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Transformed from heterogeneous to homogeneous state, an ionic liquid (IL)-based Suzuki coupling reaction was successfully implemented in a continuous microflow system. Triethylamine (Et3N) was introduced as the base, and N-methylpyrrolidinone (NMP) was used as the solvent of boronic acid, which brought about the first improvement on the reaction performance. Then, the implementation of this reaction in a continuous microflow system brought about further improvement on the reaction yield and selectivity due to better mixing condition. The combination of IL as the reaction medium and the continuous microflow system as the reactor in this work exhibited great potential for efficient Suzuki coupling reactions.

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Authors: Erika Michéli, Márta Fuchs, József Attila Tóth, Ádám Csorba and Tamás Szegi

A szerves talajok összetétele, képződési körülményei, és földrajzi, ill. domborzati elterjedése jelentősen eltér az ásványi talajokétól. A tömegükben megőrzött hatalmas mennyiségű szerves szén és környezetük biológiai sokfélesége (biodiverzitása) kapcsán a klímaváltozás által leginkább érintett talajok, ezért megkülönböztetett figyelem irányul e talajokra. Kiterjedésükre, lebomlottsági fokukra, szerves szénkészletükre igen eltérő irodalmi és térképi adatok állnak rendelkezésre. Ugyanakkor éppen a klímaváltozás vonatkozásában óriási a globális és helyi megbízható adatigény az említett kérdésekben. Hazai láptalajaink osztályozási, felvételezési és mintavételi módszereinek megújítására teszünk javaslatot a nemzetközi standardok figyelembe vételével. A megújított Láptalaj meghatározásban a legfontosabb követelmények a 20% szerves széntartalomra, a 40 cm vastagságra és az alacsony térfogattömegre vonatkoznak. Az altípus és változati tulajdonságok a lebomlottság fokát, a mélységi, kémhatás viszonyokat, ill. sók jelenlétét adják meg. A szervesanyag meghatározásra az izzítási veszteség módszerét, a térfogattömeg meghatározás mintavételezésére a rostosság függvényében a lápfúró alkalmazását vagy feltárt szelvényből nagytérfogatú bolygatatlan mintákat javasolunk.

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Authors: Gabriella Kovács, Gabriella Kulcsár, Gábor Serlegi, Mateusz Jaeger, Nicole Taylor and Ákos Pető

A Kiskunsági homokhát, a Pesti hordalékkúp-síkság, illetve a Pilis—Alpári homokhát találkozásánál az ócsai Turjánvidék szomszédságában található Kakucs—Turján mögött lelőhely a Kárpát-medence középső bronzkorában (ca. 2000/1900–1500/1450 cal BC) a Vatya-kultúra népességének egyik jellegzetes települése volt.

A területen több talajtani módszer együttes alkalmazásával lehetőség nyílt arra, hogy feltérképezzük a bronzkori település talajtani, sekélyföldtani viszonyait, illetve a régészeti lelőhely fejlődéstörténetének, tafonómiájának egyes részleteit rekonstruáljuk.

A talajtani térképező fúrások eszközének segítségével a fedő talajképződmény alatt meghatároztuk az antropogén hatásra fejlődött és módosult talajok, valamint üledékek vertikális és horizontális kiterjedését. Ennek keretében nem csak a hármas tagolású lelőhely kerítőárkainak betöltését, hanem az épületobjektumok által megjelenített megtelepedési és pusztulási rétegeket is vizsgáltuk. A pusztulási rétegként meghatározott K1 réteg magas patics- és faszéntartalmával ellentétben az alatt elhelyezkedő — minden valószínűség szerint az eredeti megtelepedési szintet megjelenítő — K2 réteg kevesebb antropogén szemcsét tartalmazott.

Kakucs—Turján mögött bronzkori lelőhelyen végzett régészeti talaj mikromorfológiai megfigyelések arra utalnak, hogy a K1 rétegben régészeti módszerekkel meghatározott két feltételezett padló szint közül egyik sem in situ helyzetű. Bár mindkét esetben megfigyelhetők padlótöredék-darabok, ezek nagy valószínűséggel áthalmozott formában vannak jelen. Ezt támasztja alá a T4-es vékonycsiszolati mintában az égetetlen padló töredékek jelenléte, amelyek tetején égetetlen talajos jellegű betöltés és égett patics található (T3). A patics körül nincs nyoma égésnek, így az is áthalmozott anyag. A korábban padlóként meghatározott rétegtani egységek (T6 ‘c’ és T7 ‘a’) ugyancsak nem in situ, hanem áthalmozott anyagként definiálhatóak. A megfigyelések arra utalnak, hogy legalább kétféle padló típussal számolhatunk a lelőhelyen. Az egyik egy igen finom szerkezetű, kifejezetten meszes, a másik pedig homokos vályog alapanyagú. Ebből az anyaghasználat, építéstechnika, ezzel együtt pedig esetlegesen a helyhasználat különbözőségére következtethetünk.

Az antropogén eredetű összetevők aránya alacsony. Talán ez is annak a jele, hogy nem egy in situ házzal/épülettel, hanem annak áthalmozott maradványaival van dolgunk. Az antropogén eredetű mikro-maradványok a mindennapi élethez kapcsolhatók (pl. hamu, faszén — égetés; csont — élelem, ételkészítés; kerámia — tárolás, fazekasság). Az elemzett vékonycsiszolatok az anyagok folyamatos áthalmozását mutatják, ami intenzív emberi jelenlétre utal.

A vékonycsiszolatokban megfigyelt, a telepen zajló anyagmozgatás, áthalmozás mértékével kapcsolatban általánosítani nem lehet. A mintázott profil azonban jól mutatja a szándékos anyagmozgatást, áthalmozást, mely a mintázás helyén sem egyszeri esemény. A padlók esetében régészetileg is bizonytalan interpretációt („feltételezett padló”) szándékoztunk megerősíteni vagy elvetni. A terepi megfigyelések szerint valószínűsíthető volt a mintázott helyen padlók megléte, melyek nem őrződtek meg minden kétséget kizáróan. A vékonycsiszolatok megfigyelései igazolták a padlók (pontosabban padló alapanyagok) meglétét, hisz valóban padló anyag került lerakásra, de ezek vélhetően nem elsődleges, azaz kialakításuk pozíciójában voltak jelen. „Bolygatatlan” padló töredéket csupán a T2-es mintában találtunk. Bár mintázáskor itt nem rögzítettük padló jelenlétét, mind az ásatási dokumentáció mind pedig a mikroszkópos megfigyelés azt mutatja, hogy in situ padlót találtunk.

A homokos/homokos vályog szerkezetnek köszönhetően a szerves (növényi) anyagok megőrződése igen rossz. Gyakorlatilag nincsenek jelen a mintákban, így ezekkel kapcsoltban nem állt módunkban megfigyeléseket tenni.

Az intenzív emberi jelenlét az egész lelőhelyen megfigyelhető, melyet a fúrások során tapasztalt változó vastagságú kultúrréteg is mutat. A telep egyes részein anyagok halmozódtak fel, kerültek lerakásra, míg máshol ilyen jellegű tevékenység nem figyelhető meg, sekélyebb üledékréteget hátrahagyva.

Mind a talajfúrások, mind pedig a vékonycsiszolatok elemzése alapján a lelőhelyképződés a következőképen vázolható:

  1. Eredeti természeti környezet
  2. Emberi megtelepedés
  3. Az eredeti/eltemetett talaj felszínének modifikációja, mely nem drasztikus, hanem folyamatos.
  4. Folyamatos emberi behatás (házak építése, mindennapi tevékenység következtében kialakuló anyagok felhalmozódása (kerámia, patics, csont, hamu stb.), anyagok áthalmozása).
  5. Telep el/felhagyása, a telep pusztulása, eltemetődése
  6. Recens talajfejlődés

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Authors: M. Dencső, E. Tóth, Gy. Gelybó, I. Kása, Á. Horel, M. Rékási, T. Takács, Cs. Farkas, I. Potyó and N. Uzinger

A talajok tulajdonságainak javítása céljából végzett bioszénnel történő kezelések hatása a különböző fizikai, kémiai és biológiai tulajdonságú talajok esetében még nem teljesen ismert. Kísérleteinket homoktalajon végeztük az MTA ATK TAKI Őrbottyánban lévő kísérleti telepén, ahol kukoricát vetettek. Hét kezelést vizsgáltunk, négy ismétlésben. Három esetben a talaj különböző dózisban bioszenet és konstans dózisú műtrágyát tartalmazott (0,1 m/m%; 0,5 m/m%; 1 m/m%; jelölésük BC0,1M; BC0,5M; BC1,0M), három esetben pedig a fent említett bioszén dózisokat egységesen 10 t/ha komposzttal egészítettük ki (BC0,1K; BC0,5K; BC1,0K). Ezek mellett pedig kialakítottunk egy bioszén és komposzt mentes abszolút kontroll (K) kezelést is. Kutatásunk során talajszondákkal monitoroztuk a talajnedvességtartalmának alakulását, valamint statikus kamrás mintavételi eljárással a talajlégzést is mértük a kezelésekben.

A talajnedvesség éves átlagát nézve 1% bioszénnel és komposzttal kezelt parcella esetében a talaj nedvességtartalma nem szignifikáns mértékben növekedett a bioszén és komposzt mentes abszolút kontroll környezethez képest. Csapadékesemények alkalmával az 1% bioszenet és komposztot tartalmazó parcellában nőtt meg legjobban a talajnedvesség, illetve hasonlóan alakult a nedvességtartalom a 0,5% bioszénnel kezelt műtrágyás parcellában is. Csapadékesemények után az összes bioszenet és műtrágyát, illetve bioszenet és komposztot tartalmazó parcellában gyorsabban száradt ki a talaj a kontrollhoz képest. A csapadékban szegényebb, szárazabb időszak alkalmával egyedül az 1% bioszenet és komposztot tartalmazó kezelés talajnedvessége volt magasabb a kontrollhoz képest, a 0,5% bioszénnel és műtrágyával kezelt, komposzt mentes esetben a nedvesség hasonlóan alakult a kontrollhoz viszonyítva, az összes többi esetben jóval az alatt maradtak az értékek.

Összességében megállapítható, hogy a komposztot tartalmazó talajok érzékenyebben reagáltak a csapadékra, a legjobb vízgazdálkodást az 1% bioszén és komposzt kezelés esetében értük el. Önmagában a bioszén nagy mennyiségű (1,0 m/m%) adagolása nem volt egyértelműen talajnedvesség-növelő hatású.

A bioszén szén-dioxid forgalomra történő hatását a talajlégzés mérésével vizsgáltuk. A bioszénnel, valamint műtrágyával kezelt és a kontroll kezelések között csak néhány esetben volt különbség. A komposzttal kevert bioszén kezelések alkalmával hasonló eredményre jutottunk, mint a műtrágyával kevert bioszén esetében. Eredményeink alapján arra következtethetünk, hogy a talajlégzés nem függött a bioszén dózisától. A bioszén talajlégzésre gyakorolt hatása közvetett módon, a talajnedvesség befolyásolásán keresztül valósul meg, mivel bioszenet alkalmazva bizonyos esetekben a talajnedvesség emelkedett a kontrollhoz képest, ekkor a talajlégzés ugyancsak magasabb lett, amely jelenség a komposzttal kezelt esetekben jól megfigyelhető volt.

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Authors: János Kalmár, László Kuti, János Kátai, Renáta Figler and György Füleky

A Nyírség egyik jellegzetes talajtípusa a kovárványos barna erdőtalaj. Mind hazánkban, mind külföldön sokan vizsgálták a kovárványképződést és állítottak fel természettudományosan megalapozott elméleteket a képződés mikéntjére vonatkozóan. Leggyakrabban a vas-vegyületek lefelé irányuló mozgásávbal és adott mélységben történő kicsapódásával próbálták meg leírni a jelenséget. Munkánk célja ásványtani, talajtani és mikrobiológiai vizsgálatok segítségével megválaszolni a kovárványképződésének kérdését.

A Nyírség tamáspusztai homokdomb alapvetően homogénnek tekinthet ásványi összetételét tekintve. A kovárványszintek képződésének korábban leírt kémiai és szemcseösszetételbeli kritériumai teljesülnek (pH 4.5–6.5 közé esik, a szemcseösszetétel pedig a kovárványrétegben meghaladja a leiszapolható rész 10 %-ot). Részletesen vizsgálva a kovárványrétegeket benne a homokszemcsék korrodáltak, töredezettebbek, ami mind egykori gyökérnedvek korróziójának eredménye lehet. A homokszemcsék kötőanyaga a kovárványrétegben elsősorban vas-oxihidroxidból áll, és a kovárványréteg eredetileg képlékeny, gyúrt, szakadozott szerkezetet mutat. A kovárványréteg felső része erodált, ami egykori talajfelszínen történő elhelyezkedését jelzi. A réteg alsó része tagolt és gyakran benyúlik az alatta elhelyezkedő homoktestbe. Véleményünk szerint a vas-oxihidroxid kiválások a kovárványrétegben alapvetően biológiai (növényi vas felvétel, majd elhalás után mikrobiális bontás segítségével létrejött vas-oxihidroxid akkumuláció) akkumulációs és kiválási folyamatokra utalnak. Mindezek alapján úgy gondoljuk, hogy a kovárványrétegek az egykori homokdomb felszínén képződtek és nem később bekövetkezett vasmozgás során jöttek létre.

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Kísérleti munkánk célja volt, hogy műtrágyázási tartamkísérletben vizsgáljuk a N-, P- és K-ellátottság hatását a lóbab szárazanyag-felhalmozására és tápelemfelvételére. A műtrágyázási tartamkísérletet 1989-ben állítottuk be mélyben karbonátos csernozjom réti talajon, 4-4 N-, P- és K-ellátottsági szinten, teljes kezelés-kombinációban, 64 kezeléssel. A tápelem-felvételi vizsgálatokra 15 kezelést választottunk ki. Jelen dolgozatban a 2001. évi kísérlet eredményei szerepelnek, melyek alábbiakban foglalhatók össze:

A lóbab tenyészidejének első felében a 60. napig, a virágzás-hüvelyképződés kezdetéig a szárazanyag-felhalmozás mérsékelt ütemű, az összes biomassza tömegnek 26%-a halmozódik fel. Az intenzív szárazanyag beépülés a hüvely és magképződés időszakára esik, és a tenyészidő 90. napján a levél + szár tömege eléri maximumát (2,25 t ha−1), és a hüvely + mag tömege (2,64 t ha−1) az összes szárazanyag-termésből 54%-ban részesedik. A teljes érés fázisában, a tenyészidő 115. napján a maximális földfeletti szárazanyag-tömegből (5,72 t ha−1) a mag 54%- ban (3,07 t ha−1), a levél + szár 30%-ban (1,69 t ha−1) és a hüvely 16%-ban (0,96 t ha−1) részesedik.

A tenyészidő 35. napján, a lóbab 5-6 leveles fejlettségében a legnagyobb a leveles szár makro elem koncentrációja, ami a teljes érésig fokozatosan csökken. A hüvelytermésben a N-, P-, K- és Mg-koncentráció ugyancsak hígulást mutat, míg a Na és Ca esetében koncentráció növekedés tapasztalható. A növényi részek között N-ben és P-ban a mag a leggazdagabb. A magba több K épül be, mint a leveles szárba, míg Mg-ból kevesebb. A leveles szár Cu- és Fe-tartalma a teljes érésben a legnagyobb, míg a Zn- és Mn-koncentráció a tenyészidő alatt fokozatosan csökken. A Cu és a Zn elsősorban a magban koncentrálódik, míg a Mn és a Fe a leveles szárban.

A lóbab összes N- és P-felvételének maximumát a tenyészidő végén, a teljes érésben éri el. A növénybe épült összes K, Na, Ca és Mg mennyisége a hüvelytelítődés-magképződés időszakában tetőzik, majd a teljes érésig csökken. A lóbab által felvett összes makro elemből a magban halmozódik fel a N 83%-a, a P 82%-a, a K 45%-a, a Na 8 %-a, a Ca 10 %-a és a Mg 48%-a. A leveles szárban pedig a N 7%-a, a P 12%-a, a K 21%-a, a Na 66%-a, a Ca 82%-a és a Mg 33%-a.

A teljes érésben végzett tápelem-felvételi vizsgálatok alapján a lóbab fajlagos elemfelvétele 1 tonna magterméshez a hozzátartozó mellékterméssel együtt a következő: N 61,8 kg, P 9,6 kg (P2O5 22,0 kg), K 22,0 kg (K2O 26,4 kg), Na 5,1 kg (Na2O 6,9 kg), Ca 5,8 kg (CaO 8,1 kg); Mg 3,4 kg (MgO 5,7 kg) ; Cu 15 g, Zn 75 g, Mn 50 és Fe 374 g.

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Authors: Tibor Szili-Kovács, Ágnes Bárány, Anna Füzy, Tünde Takács, Gergely Krett, Ramóna Kovács and Andrea Borsodi

A szikes talajok szélsőséges vízháztartásuk, nagy sótartalmuk és alkalikus kémhatásuk miatt az élőlények alkalmazkodását alaposan próbára teszik. A talaj mikrobiális közösség katabolikus aktivitás mintázatát hasonlítottuk össze három szikes tó, a Böddi-szék, a Kelemen-szék és a Zab-szék (Felső-Kiskunsági szikes tavak) partközeli vegetációjának rizoszférájában az iszaptól a zsiókáson és a mézpázsiton keresztül a homoki legelőig. Feltételeztük, hogy a szikes jellegben és a növényzetben meglévő különbségek a mikrobiális közösségre is hatást gyakorolnak. Kezdeti eredményeink azt mutatták, hogy a szubsztrát hasznosítási mintázat alapján az egyes minták jól elkülönültek egymástól. Az alaprespiráció elsősorban a talaj humusztartalmával mutatott szoros összefüggést. A katabolikus aktivitás mintázatokat 5 szubsztrát alapján a gázkromatográfiás SIR méréssel a pH és EC, míg 15 szubsztrát alapján mikrorespirációval a pH és humusztartalom szignifikánsan befolyásolta, a növényzet közvetlen hatása kevésbé volt igazolható.

A szélsőséges talajtulajdonságokkal jellemezhető élőhelyeken, mint amilyenek a szikesek, a növények túlélésében az arbuszkuláris mikorhiza (AM) gombák fontos szerepet játszanak. Az AM gombák kolonizációjában jelentős különbség adódott két domináns növényfaj, a sziki őszirózsa és a sziki mézpázsit között, az előbbi jóval erőteljesebb kolonizációt mutatott. Ugyanazon növényfaj AM kolonizációja a három területen eltérő volt, ami nem magyarázható a talaj tulajdonságokkal.

A kutatást az OTKA (K 108572) támogatta.

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A talajok hazai és nemzetközi kutatásában egyre nagyobb szerepet kap a talajok mikrobiótájának vizsgálata. Hazai viszonylatban szikes talajokon eddig kevés ilyen irányú kutatás történt. Kutatásunkban kiskunsági szikes talajok mikrobaközösségeinek katabolikus aktivitás mintázatát vizsgáltuk Apajpusztáról származó mintákon. A mintavételhez négy, a szikesedés különböző fázisaira jellemző növényzettel rendelkező területet választottunk ki (szoloncsák vaksziknövényzet, kiskunsági szikfoknövényzet, ürmös szikespuszta és füves szikespuszta), ezek területéről a talaj mikrobiológiai szempontból legaktívabbnak tekintett 0-10 cm-es rétegét mintáztuk.

A minták néhány fontosabb talajtani paraméterét meghatároztuk (szemcseösszetétel, pH, só-, humusz- és mésztartalom, valamint néhány fontosabb tápelem mennyisége). A négy eltérő növényzetű terület között a talajtani paramétereik alapján is jelentős különbségeket tapasztaltunk.

A minták mikrobiológiai aktivitását az itthon még kevéssé ismert mikrorespirációs (MicroRespTM) módszerrel vizsgáltuk. Ennek során a talajmintákhoz 23 különböző szerves szubsztrátot adtunk, és az általuk indukált légzési válaszon keresztül mértük, hogy az egyes talajminták mikrobaközösségei milyen mértékben képesek hasznosítani az egyes szubsztrátokat. Az így kapott, közösségre jellemző katabolikus aktivitás mintázatokat főkomponens elemzéssel és kanonikus korreszpondancia elemzéssel értékeltük.

Eredményeink alapján a mikrorespirációs módszer egyértelműen alkalmas az általunk vizsgált talajok mikrobiótájának elkülönítésére. Az egyes minták katabolikus aktivitás mintázatai közötti különbségek egybevágtak a minták közötti, talajfizikai és —kémiai tulajdonságban megfigyelt eltérésekkel.

A kutatást az OTKA (K 108572) támogatta.

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Recently, considerable numbers of poisoning cases have been reported owing to the ingestion of three structurally related organophosphorus pesticides (OPPs): chlorpyrifos (C), quinalphos (Q), and triazophos (T). Normal-phase high-performance thin-layer chromatography (NP-HPTLC) on silica gel 60 F254 and reversed-phase (RP)-HPTLC on silica gel 60 RP-18 W F254 were used to evaluate the retention and separation data for these three pesticides. Optimum separation of pesticides has been achieved on NP-TLC layer with n-hexane—acetone 9:1 (v/v) and on RP-TLC layer using acetonitrile—water 8:2 (v/v) as the mobile phases. The R F values of pesticides increased with increasing acetone content in the case of NP-HPTLC and decreasing water content in RP-HPTLC. Under the chromatographic conditions used, in regard to changes in the mobile phase composition, C adsorbed most strongly on the silica gel RP-18 plate. A linear relationship between R M values and mobile phase composition was established. Densitometric detection was performed at the respective λ max value of the pesticide. The peak resolution (RS) was greater than 1.25 for all compound pairs (C-Q, Q-T, and C-T). The pesticide samples are stable on plate and in solution at room temperature as well as at 4°C. The ultraviolet (UV) spectra (λ max) of the OPPs were apparently unaffected by changes in pH. No significant chromatographic interference was noticed from other OPPs of forensic relevance.

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Patrinia scabiosaefolia Fisch. (PSF), a well-known traditional Chinese medicine, has been demonstrated to show therapeutic effects on inflammatory bowel disease. In this study, a rapid and sensitive method using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) was developed for identification of the major constituents in PSF. The separation analysis was performed on Waters Acquity UPLC system, and the accurate mass of molecules and their fragment ions were determined by Q-TOF-MS. Thirty-one constituents, including triterpenoids, iridoids, flavonoids, and organic acids were detected and tentatively deduced on the basis of their element compositions, tandem mass spectrometry (MS/MS) data, and relevant literatures. Twelve constituents were discovered for the first time in PSF. The results demonstrated that hederagenin-type and oleanolic acid-type saponins were the main constituents of PSF. Our work provides a certain foundation for further quantitation of major chemical constituents and in vivo pharmacokinetic studies of PSF. Moreover, the analytical approach developed herein has proven to be generally applicable for profiling the chemical constituents in traditional Chinese medicines (TCMs) and other complicated mixtures.

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New polyacrylate-based monosized-porous polymer beads were proposed as a stationary phase for the separation of polar compounds by microbore reversed-phase chromatography. For this purpose, monosized-porous poly(glycerol dimethacrylate-co-glycerol-1,3-diglycerolate diacrylate), poly(GDMA-co-GDGDA), beads with hydroxyl functionality were synthesized by a modified seeded polymerization. The selected octadecylating agent, stearoyl chloride (SC), was covalently attached onto the hydrophilic beads via a direct, single stage reaction with a simple synthetic route. SC attached-poly( GDMA-co-GDGDA) beads were slurry-packed into the microbore columns and used as separation medium microbore reversed-phase chromatography. The stationary phase was used for separation of alkylbenzenes and polar analytes by micro reversed-phase chromatography, using mobile phases with low acetonitrile content. Theoretical plate number (TPN) values up to 12,000 plates m−1 and 10,000 plates m−1 for alkylbenzenes and polar analytes, respectively, were achieved. The results also showed that poly(GDMA-co-GDGDA) hydrogel beads are a promising starting material for a number of chromatographic applications like reversed-phase (RP) chromatography, hydrophilic interaction chromatography (HILIC), ion-exchange chromatography (IEC), and affinity chromatography with a single-stage surface modification.

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The use of polypropylene materials in industry for food packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these additives are potential risk for human health. In this context, an efficient analytical method for the quantitative determination of three antioxidants (2,6-di-tert-butyl-4-methylphenol (BHT), dibutylhydroxyphenylpropionic acid stearyl ester (Irganox 1076), and tns-(2.4-di-tert-butyl)-phosphite (Irgafos 168)) and five ultraviolet stabilizers (2-(2′-hydroxy-5′-methylphenyl) (UV-P), (2′-hydroxy-3′-tert-5′-methylphenyl)-5-chloroben zotriazole (UV-326), 2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327), 2-(2H-benzotriazol- 2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol(UV-329), and 2-hydroxy-4(octyloxy) benzophenone (UV-531)) in polypropylene food packaging and food simulants by high-performance liquid chromatography (HPLC) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic condition were studied in order to determine operating conditions. The analytical method showed good linearity, presenting correlation coefficients (R ≥ 0.9977) for all additives. The limits of detection and quantification were between 0.03 and 0.30 μg mL−1 and between 0.10 and 1.00 μg mL−1 for eight analytes, respectively. Average spiked recoveries in blank polypropylene packaging and food simulants were in the range of 80.4–99.5% and 75.2–106.7%, with relative standard deviations in the range of 0.9–9.1% and 0.2–9.8%. Dissolving the polypropylene food packaging with toluene and precipitating by methanol was demonstrated more effective than ultrasonic extract with acetonitrile or dichloromethane for extracting the additives. The method was successfully applied to commercial polypropylene packaging determination, Irgafos 168 and UV-P were frequently found in six commercial polypropylene films, and the content ranged from 166.47 ± 5.11 to 845.27 ± 29.31 μg g−1 and 2.10 ± 0.29 to 19.23 ± 1.26 μg g−1, respectively.

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Authors: Mei-Xia Zhu, Sheng-Nan Li, Hai-Dan You, Bin Han, Zhi-Ping Wang, Yan-Xi Hu, Jin Li and Yu-Feng Liu

High-performance liquid chromatography coupled with photodiode array detection and evaporative light scattering detection (HPLC—DAD—ELSD) was established to determine paeoniflorin and albiflorin simultaneously in Radix Paeoniae Rubra. The assay was performed on a Diamonsil C18 (4.6 mm × 250 mm, 5 μm) column by a gradient elution program with acetonitrile and aqueous formic acid (0.05% v/v) as mobile phase at a flow rate of 1.0 mL min−1. The detection wavelength of DAD was 230 nm, and the evaporator tube temperature of ELSD was set at 110 °C with the nebulizing gas flow rate of 3 L min−1. The temperature of column was kept at 30 °C. The linear ranges of paeoniflorin and albiflorin were within 0.050–1.510 mg mL−1 and 1.007–5.035 mg mL−1. The recoveries of paeoniflorin and albiflorin were 96.2–102.9% and 95.0–102.4%, respectively, while the relative standard deviation (RSD) of them was 0.2–2.5%. This method was quick, simple, accurate, and specific. It could be used for the quality control of Radix Paeoniae Rubra. The proposed approach was expected as a powerful tool for the quality control of Radix Paeoniae Rubra.

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Quantification of carbohydrates and metabolites in fermentation processes can be considered as key factor in determining yield and productivity for a better understanding of the microbial behavior under different conditions. The main aim of the present study was to develop and set up analytical methods for detecting complex sugar and/or metabolite mixtures in fermentation broth based on high-performance thin-layer chromatography (HPTLC). HPTLC is a fast and accurate method of separating complex mixtures, based on planar development. The proposed methods involved the separations of a mixture of monosaccharides (glucose, xylose, arabinose, and rhamnose) deriving from delignification and hydrolysis of hazelnut shells and the corresponding sugar alcohols (xylitol, arabitol, and sorbitol) obtained by fermentations of Candida tropicalis spp., a yeast able to ferment aldoses to produce sugar alcohols. HPTLC methods were set up on simple chamber development and using instrumental techniques like overpressured layer chromatography (OPLC). This approach has enabled the simultaneous monitoring of several samples with significant time and money savings. Different multicomponent broths at different times of fermentation were analyzed.

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Linaclotide, a first-in-class guanylate cyclase-C agonist, was recently approved by US Food and Drug Administration (FDA) as a promising pharmacotherapy for the management of constipation-predominant irritable bowel syndrome (IBS). In this communication, we present a novel stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method for the quantitative determination of linaclotide along with its degradation products. During the International Conference on Harmonization (ICH) prescribed stress study, linaclotide was found susceptible to degrade under hydrolytic (acid and base) and oxidative (peroxide) conditions. The separation of the degradants from the analyte was achieved on a Zorbax Eclipse XDB C8 Column (250 mm × 4.6 mm, 5 μm) using 0.01 N potassium dihydrogen orthophosphate buffer and acetonitrile (80:20 v/v) as mobile phase at a flow rate of 1.00 mL min−1 at column temperature of 40 °C. The detection of the column effluents was realized on a photodiode array detector set at 220 nm. Under the above optimal condition, the method was validated with respect to specificity, linearity, range, precision, robustness, and sensitivity in compliance to the regulatory requirements.

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A key reaction in one of the routes to efavirenz, an essential drug used in the treatment of acquired immunodeficiency syndrome (AIDS), is the ortho-lithiation reaction of N-Boc-4-chloroaniline. For the first time, we demonstrate that the reaction may be conducted using n-BuLi and show that the reaction may be performed in a flow reactor with a significantly higher yield (70%) compared to batch (28%) when using n-BuLi for the ortho-metalation reaction at a temperature of −45 °C. In addition, it was shown that tetramethylethylenediamine (TMEDA) did not need to be added to the flow reaction, which simplified the purification procedure.

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Authors: András Makó, Tamás Varga, Hilda Hernádi, Viktória Labancz and Gyöngyi Barna

A lézerdiffrakciós szemcseanalízis egy korszerű módszer a talajmechanikai vizsgálatokban, ám egy egységes mérési szabvány bevezetése (akár műszerhez köthetően) nagymértékben növelné a mérések reprodukálhatóságát. A mérések tekintetében kiemelt szerepe van az előkészítő módszereknek (talajszerkezetet kialakító kötőanyagok roncsolása, elemi szemcsék diszpergálása), azonban ezen a téren is hiányzik az egységes szabványosítás. A tanulmányozott közlemények alapján megállapítható, hogy mind az optimális mintaelőkészítési módszer, mind pedig a legmegfelelőbb műszerbeállítás nagymértékben függ a mérni kívánt minta fizikai és kémiai sajátságaitól. A mérési eredmények hagyományos ülepítéses módszerrel kapott eredményekkel történő összehasonlítására szolgáló konverziós módszerek (frakció mérethatárváltások, illetve konverziós egyenletek) használhatósága is talajminta- és LDM vizsgálati módszer-függő. A lézeres szemcseanalízis alkalmazása a talajok aggregátum-stabilitás vizsgálata során ígéretes módszertani lehetőség, ám a mérések értelmezése és az összahasonlíthatóság megteremtése végett ezen a téren is elkerülhetetlen a szabványosítás.

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This study aims at establishing a thin-layer chromatographic (TLC) scanning method for the determination of three alkaloids in Sophora alopecuroides and preliminary screening of antioxidant active components in S. alopecuroides with TLC—bioautography technology. The alkaloids in S. alopecuroides were identified by silica gel thin-layer chromatography; the expansion agent was toluene— acetone—methanol—ammonia—water (8:3:0.2:0.5:8), and the chromogenic agent was modified bismuth potassium iodide solution, sophoridine, matrine, and sophocarpine in S. alopecuroides by TLC scanning at 500 nm. The linear ranges were 0.4152–2.4912 μg for sophordine, 0.4245–2.5470 μg for matrine, and 0.4101– 2.4606 μg for sophocarpine, with correlation coefficients of 0.9939, 0.9956, and 0.9975. Ultraviolet (UV) method was used to determine the total scavenging activity of the 2,2-diphenyl-1-picrylhdrazyl (DPPH) free radical. The best TLC identification condition was selected, and the antioxidant activity of DPPH was screened with the color. DPPH tests indicated that IC50 of S. alopecuroides was 0.40 mg mL−1. The TLC—bioautography technology showed the alkaloids in the purple background, and a white spot was not evident. Precision, accuracy, and repeatability of the TLC scanning method were evaluated, and the results were in accordance with the requirements of methodology validation. S. alopecuroides exhibits certain antioxidant activity, but the three alkaloids do not exhibit an evident antioxidant effect, and the unknown components of S. alopecuroides show weak antioxidant effect. The specific components need further studies.

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As it was shown in earlier experiments, magnetic field can influence various processes taking part in nature. One of them might be the permeation of chemical compounds across biological membranes. An excellent tool for investigations on that subject is chromatography. Basing on retention measurements performed using reversed-phase thin-layer chromatography (RP-TLC) and micellar liquid chromatography—thin-layer chromatography (MLC—TLC), descriptors of lipophilicity were calculated for the group of 1,2,4-triazole derivatives. The experiments were performed in moderate (≈0.4 T) magnetic field and simultaneously outside it. The analysis of the obtained data showed that the presence of an external static magnetic field can alternate the obtained descriptor values which allows to assume that the ability of passive permeation of the investigated substances across cellular membrane also changes. The intensity of changes depends on the structure of the chromatographed substance and the lipophilicity measurement method.

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Commercially available hop pellets of different origins were extracted by use of ethanol and water, chromatographed on silica layers by use of nonaqueous eluents, chemically derivatized and observed in ultraviolet (UV) light for the localization of component bands. The plates were developed in optimized systems, and direct bioautographic method by use of Bacillus subtilis and Escherichia coli strains was applied for the examination of the antimicrobial activities of hop components. The method enables for the identification of bactericidal/bacteriostatic components in the extracts of different polarities and shows differences in the composition of extracts from various varieties from an antimicrobial point of view.

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Room temperature ionic liquids are a new class of solvents of potential interest for liquid chromatography. Ionic liquids possess a combination of physical and solvation properties that are complementary to conventional organic solvents. Applications in liquid chromatography are currently limited by their unfavorable viscosity and low-wavelength absorption in the ultraviolet (UV) region. In addition, for planar chromatography, the absence of a vapor pressure does not allow evaporation of ionic liquid solvents after development. The room temperature ionic liquids are good solvents for nonionic compounds with a different blend of intermolecular interactions compared with conventional organic solvents as indicated by solvatochromic measurements and the system constants of the solvation parameter model. Current applications in column and planar chromatography are reviewed to demonstrate the potential of room temperature ionic liquids as mobile phases or mobile phase additives in separation science. A real breakthrough in their use, however, requires the identification of new room temperature ionic liquids with viscosity closer to those of conventional organic solvents as well as addressing other minor issues described in the text.

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Authors: Aneta Hałka-Grysińska, Radosław Ł. Gwarda, Krzysztof Pawełek, Tomasz Baj and Tadeusz H. Dzido

Satisfactory separation of a test mixture of 19 dyes with a general elution problem was obtained by reversed-phase stepwise gradient thin-layer chromatography with single void volume of the mobile phase. An effect of the supplementary mobile phase flux to the surface of the adsorbent layer, observed previously, was eliminated. This improves the flow profile of the mobile phase and the shape of spots, and increases the repeatability of the results within the same plate and between studies. The experimental values of the relative zone/spot position, R p g, showed good correlation with the results predicted by the computing calculation.

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In this study, thin-layer chromatography—direct bioautography (TLC—DB) was used for guiding the isolation and identification of antibacterial constituents of Thymus vulgaris L. ethanol extract. This TLC—bioassay method enables the separation and detection of active components directly on the surface of chromatographic plates. They can be identified by comparison with reference substances or using physicochemical methods, preferably spectroscopic ones (liquid chromatography—tandem mass spectrometry [LC—MS/MS], in the presented paper). The described method belongs to the effect-directed analyses (EDA). Seven bacterial strains were used as test organisms, both pathogenic and nonpathogenic, including methicillin-resistant Staphylococcus aureus as well as luminescent bacteria like Aliivibrio fischeri. Five fractions with the widest antimicrobial spectra were detected using TLC—DB, isolated by semi-preparative TLC and subjected to LC—MS/MS analyses. Finally, two bioactive components were tentatively identified, basing on their fragmentation pattern, as eriodictyol and 4,4′-dihydroxy-5,5′-diisopropyl-2,2′-dimethyl-3,6-bifenylodion.

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Overpressured layer chromatography (OPLC), ensuring pumpforced constant mobile phase flow and the possibility of overrun, offers the expanded exploitation of fine-particle adsorbent layers for a longer development distance. Using an infusion—transfusion OPLC method with a 26-cm long development, the separation of clove, rosemary, eucalyptus, tea tree, spearmint, thyme, and cinnamon bark essential oil components was achieved with good resolutions. In the combination of OPLC and Aliivibrio fischeri assay, the main essential oil components eugenol, borneol, (−)-R-carvone, thymol, and trans-cinnamaldehyde exhibited antibacterial effect. The OPLC—2,2-diphenyl-1-picrylhydrazyl (DPPH*) test showed two antioxidant components: eugenol and thymol.

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In this study, authors propose a simple and cost-effective two-dimensional thin-layer chromatography (2D-TLC) method for the simultaneous determination of eleven standards alkaloids: allocryptopine (A), berberine (Be), boldine (Bo), chelidonine (Ch), glaucine (G), papaverine (Pa), emetine (E), columbamine (Col), magnoflorine (M), palmatine (Pal), and coptisine (Cop). Separation of the alkaloid mixture was achieved by 2D-TLC using an aqueous mobile phase (RP) in the first dimension (80% methanol + water + 0.05 mL−1 diethylamine) and a normal phase (NP) in the second dimension (18% methanol, 18% acetone in 63% diisopropyl ether containing 1% ammonia, v/v) on bilayer Multi-K CS5 plates. The composition of the mobile phases was optimized in terms of retention, separation selectivity, spots symmetry, and system efficiency. The procedure was evaluated in terms of natural samples analysis. Magnoflorine and berberine were identified in Thalictrum foetidum root extract. Additionally, the alkaloids in the extract sample were confirmed by high-performance liquid chromatography—diode-array detection method.

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We present a two-dimensional (2D) planar chromatographic separation of estrogenic active compounds on RP-18 W (Merck, 1.14296) phase. A mixture of 8 substances was separated using a solvent mix consisting of hexane, ethyl acetate, acetone (55:15:10, v/v) in the first direction and of acetone and water (15:10, v/v) in the second direction. Separation was performed on an RP-18 W plate over a distance of 70 mm. This 2D-separation method can be used to quantify 17α-ethinylestradiol (EE2) in an effect-directed analysis, using the yeast strain Saccharomyces cerevisiae BJ3505. The test strain (according to McDonnell) contains the estrogen receptor. Its activation by estrogen active compounds is measured by inducing the reporter gene lacZ which encodes the enzyme β-galactosidase. This enzyme activity is determined on plate by using the fluorescent substrate MUG (4-methylumbelliferyl-β-d-galactopyranoside).

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The most current in vitro and in vivo results in the BioArena system and under greenhouse conditions provide a good opportunity for a fundamental renewal of biological detections and interactions in layer liquid chromatography. The adsorbent bed in a column liquid arrangement is not suitable for biological detection because the living cells do not grow there. Contrarily, the planar adsorbent layer enables the in situ biodetection of antimicrobials and the interactions among separated compounds, cells, and further various cofactors (molecules), making the study of mechanisms of action possible. The basic elements of the time- and dose-dependent quadruple immune response of plants to pathogens in relation to the function and reactions of formaldehyde and its reaction products (mainly endogenous ozone) were demonstrated. This finding opens a new horizon in the field of disease resistance in plants and perhaps in general in the biological world. These results give a good basis and possibility for studying and understanding the unique high-dilution phenomena as well, and at that time, they promise the elimination of century contradictions in this field.

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Conventional flash vacuum pyrolysis is the best method for the preparation of isothiocyanate-substituted allenes by [3,3]-sigmatropic rearrangement. These synthetically useful allenes undergo a variety of successive reactions; the most prominent is thiazole ring formation after nucleophilic attack at the isothiocyanate carbon. We now present the development and application of the solution spray method in flash vacuum pyrolysis of low- or nonvolatile propargyl thiocyanates. By using model reactions, the setup was optimized for a synthetic scale approach utilizing also steel nozzles (distributed for oil-fired heating furnaces) for spray generation. Selected examples emphasize advantages such as enabling gas-phase reactions of nonvolatile compounds and improvement of challenging syntheses via highly reactive species under different operating conditions (400–600 °C, 0.01–0.05 mbar).

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Four geminal ionic liquids (GILs), namely, 1,4-bis(1,1′-butyl-3,3′- methylene- imidazolium)-benzene bis[(trifluoromethyl)sulfonyl]imide (BBMIB-NTf2), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene tetrafluoroborate (BBMIB-BF4), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene hexafluophosphate (BBMIB-PF6), and 1,4-bis(1,1′-methyl-3,3′-methylene-imidazolium)-benzene bis[(trifluoromethyl) sulfonyl] imide (BMMIB-NTf2), were synthesized. They were statically coated onto the inner walls of fused-silica capillary columns and used as stationary phases for gas chromatography. The evaluation of BBMIB-NTf2, BBMIB-BF4, BBMIB-PF6, and BMMIB-NTf2 as stationary phases is reported here for the first time. These new stationary phases exhibit efficiencies of at least 2.3 × 103 plates per meter. Abraham solvation parameter model was used to evaluate the solvation characteristics. The system constants indicated that the dipolarity/polarizability and the hydrogen-bond basicity play a major role among five molecular interactions between stationary phases and solute molecules. A fundamental understanding into the solvation characteristics of these GILs can be used as a guide to choosing the appropriate geminal ionic liquids for specific applications in various fields. The chromatographic separation performance was evaluated by a Grob test mixture, n-alkanes, alcohols, and aromatic isomers. Furthermore, the thermal stability was tested. The present results demonstrate that these geminal ionic liquids stationary phases possess excellent chromatographic separation performance and good thermal stability (at least up to 270 °C) and may be applicable as gas chromatography stationary phases for more application.

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In this short communication, we report on three striking phenomena of the circadian rhythm. One was observed with the non-linear concentration changes of the monomeric L-Cys and the non-linear yields of the L-Cys derived peptides, when undergoing spontaneous non-linear peptidization. The other one was observed with the binary L-Phe-L-Pro system, and the third one with L-Ser, D-Ser, and DL-Ser. So far, no analogous reports have been released on the circadian rhythm of the spontaneous non-linear peptidization of proteinogenic amino acids in a sterile abiotic environment (70% aqueous acetonitrile, or 70% aqueous methanol solutions). At the moment, we cannot find any rational explanation of this phenomenon, yet it seems highly probable that its origin is analogous to or even of a primordial nature for the circadian rhythm phenomena abundantly found in biological samples by other researchers. An experimentally established lack of the circadian rhythm with peptidization of the non-proteinogenic amino acid (D-Ser) can encourage us to revisit a still unsolved question of homochirality preconditions.

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Authors: Sarah E. Smith, Zachary J. Huba, Fahad Almalki, J. R. Regalbuto, John Monnier and Everett E. Carpenter

Magnetic nanomaterials have many applications in the fields of catalysis, medicine, and environmental studies. An emerging synthetic method capable of large-scale production of nanomaterials is a continuous-flow microreactor. However, translating known conventional benchtop reactions to a continuous-flow system can be difficult; reaction parameters such as reaction time and viscosity of the solution are significant limitations in flow-based systems. In this study, nanocrystalline Cu—Ni and Cu—Co core—shell materials were successfully synthesized using a capillary microreactor in a one-step process. Ethanol was used as solvent, allowing for faster reaction times and reduced reaction solution viscosity, compared to similar bench top synthetic protocols. Both nanocomposites were tested for activity in Fischer—Tropsch and showed activity above 220 °C. This study shows that a continuous-flow capillary microreactor has the capabilities to make complex metallic nanomaterials at short reaction times with proper selection of reaction solvent systems.

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A continuous synthesis route of the metal—organic framework (MOF) CPO-27-Ni (also known as Ni2(dhtp), Ni/DOBDC or Ni-MOF-74) from aqueous solutions of the nickel acetate and sodium salt of the 2,5-dihydroxyterephtalate linker using tubular reactor techniques has been developed. When running the reaction at 90 °C, a conversion of above 90% is reached in just 20 min. The resulting MOF has a specific surface area (Brunauer—Emmett—Teller [BET]) of around 1085 m2/g and a powder X-ray diffraction pattern consistent with the known CPO-27-Ni structure. Scanning electron microscopy clearly shows that crystallite sizes around 40 nm are obtained when using the tubular reactor approach, while state-of-the-art batch synthesis in water typically gives micrometer-sized crystallites as product. The tubular reactor setup can be easily up-scaled by parallelization.

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The objective of this study was to develop and validate an assay method for simultaneous determination of atenolol, furosemide, losartan, and spironolactone in pharmaceutical formulations. A reverse-phase high-performance liquid chromatography procedure was developed, using a Kinetex® C-18 column (100 mm × 4.6 mm, 2.6 μm). The mobile phase was composed of methanol—water (75:25 v/v, pH 3.0, adjusted with phosphoric acid), with a flow rate of 0.4 mL min−1. All drugs were separated in less than 5 min. The method was validated according to International Conference on Harmonization (ICH) and Association of Official Analytical Chemists (AOAC) guidelines. The method showed linearity in a concentration range of 0.75–12.0 μg mL−1 for atenolol (r = 0.9995), 0.30–12.00 μg mL−1 for furosemide (r = 0.9997), 0.45–12.00 μg mL−1 for losartan (r = 0.9995), and 0.45–12.0 μg mL−1 for spironolactone (r = 0.9999). The method also showed repeatability and precision. The three-day average intra-day precisions were 101.35 ± 0.74% for atenolol, 95.84 ± 1.44% for furosemide, 98.90 ± 1.16% for losartan, and 97.19 ± 0.18% for spironolactone. Similarly, the inter-day precisions were 101.34 ± 0.72% for atenolol, 95.84 ± 0.1.50% for furosemide, 98.90 ± 1.17% for losartan, and 97.19 ± 0.83% for spironolactone. The method accuracy was also tested and validated — in this case, the average recovery values were 100.18 ± 1.20% for atenolol, 99.83 ± 1.54% for furosemide, 100.07 ± 0.95% for losartan, and 99.94 ± 0.93% for spironolactone. Finally, the method was successfully applied in the simultaneous determination of atenolol, furosemide, losartan, and spironolactone in magisterial formulas, as well as in commercial pharmaceutical formulations.

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A new way to perform reactions in core—shell double emulsions is reported herein. The phase boundaries of the threephase droplet flow were used to pressurize the reactants in the shell liquid, enhancing the reaction rate of a cycloaddition greatly in comparison to known methods. As key parameters, solvophobic effects and precise control over the droplet sizes were used to exploit a reaction with a negative volume of activation. The internal pressure of the reaction solution was regulated purely by the thickness of the shell liquid without adding additional reagents. Additionally, the reaction performed better when the core droplet was used to stir the shell droplet, considerably improving the mass transfer inside the otherwise diffusion-limited process.

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The hydrodistilled essential oil from flowering aerial parts of Ocimum gratissimum L. (Lamiaceae) growing desolately in South India was examined to determine its composition. The oil was analyzed by gas chromatography equipped with flame ionization detector (GC–FID) and gas chromatography coupled with mass spectrometry (GC– MS). Forty-one constituents were identified, representing 99.4% of the total oil. The main components were identified as eugenol (57.1%), α-bulnesene (15.6%), and β-caryophyllene (14.2%). Phenylpropanoids (57.3%) and sesquiterpene hydrocarbons (31.6%) were the prominent groups of compounds, followed by oxygenated sesquiterpenes (6.5%), oxygenated monoterpenes (3.0%), and monoterpene hydrocarbons (1.0%). The compound α-bulnesene was identified for the first time in this report. The essential oil was found to be eugenol–α-bulnesene–β-caryophyllene chemotypes.

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In this Section of the journal, the literature on continuous flow synthesis (primarily organic synthesis and functional materials) from the period of October — December 2016 is presented. All the publications are listed ordered by journal name, with two Review articles appearing at the end. In this quarter the number of papers on continuous flow organic synthesis is relatively less as a few special issues are planned in the coming months. Two contributions on machine learning for optimization in flow synthesis and the scale-up of continuous flow reactors from Eli Lilly are the real highlights of this quarter!

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Authors: S.M. Nurulain, S. Ojha, S. Dhanasekaran, K. Kuča, N. Nalin, C. Sharma, A. Adem and H. Kalász

Distribution of K027, a hydrophilic, positively charged compound is monitored in the body of pregnant mice using high-performance liquid chromatography (HPLC). Intraperitoneal injection was done on the 18th day of pregnancy; the plasma and brains of the mother mice, placentae and the fetuses’ brains were dissected following 5, 15, 30, 60, and 120 min of treatment. Significant incorporation of K027 was found in the placentae and in fetuses’ brains relative to its levels in the mothers’ plasma and brains. This incorporation warns of a possible adjustment of dose of pyridinium aldoxime antidotes in case of pregnancy. Further studies with different gestational periods and animal models are warranted.

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A new, sensitive, and selective high-performance liquid chromatography (HPLC) method with fluorimetric detection was developed for the determination of moxifloxacin (MOX) in human breast milk. MOX was precolumn derivatized with fluorescamine; the fluorescent derivative was separated on an RP C18 column using a mobile phase composed of acetonitrile–10 mM orthophosphoric acid by isocratic elution with flow rate of 0.5 mL min−1. The method was based on the measurement of the derivative using fluorescence detection at 481 nm with excitation at 351 nm. The calibration curve was linear over the range of 1–40 μg mL−1. Limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.3 and 1 μg mL−1, respectively. Intra-day and interday repeatabilities were less than 3.15%.

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The analysis of trace levels of explosives in post-blast debris is critical in homeland security, environmental analysis, and crime scene forensic investigations. A fast and a selective determination method with high recovery was developed for the common explosives 2,4,6-trinitrotoluene (TNT), 3,5-trinitro-1,3,5-triazacyclohexane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in soil, using liquid chromatography—tandem mass spectrometry (LC—MS/MS). An easy and practical sample preparation method was developed using 4.00 mL acidified acetone with 0.25% HCl. After the easy evaporation of acetone extract, 10 min LC—MS/MS analysis provided a clear separation in column. Short duration of the whole procedure allows the use of this method in routine analysis. As a result of the analysis performed in spiked soils in 50.0, 100.0, and 250.0 ng g−1 concentrations, high recoveries such as 100.4 (±8.8)% for RDX, 96.9 (±10.5)% for HMX, and 97.6 (±13.9)% for TNT were obtained. Limit of detection (LOD) and limit of quantification (LOQ) values obtained from the analysis of the spiked soils were 4.3 ng g−1 and 7.00 ng g−1 for RDX, 6.8 ng g−1 and 10.0 ng g−1 for HMX, and 18.9 ng g−1 and 38.0 ng g−1 for TNT, respectively. The Horwitz Ratio (HorRat) calculation was used to evaluate if the inter-day and inter-analyst precisions were in the acceptable limits. The method was successfully applied to three artificial explosion samples for detection of explosives.

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Selection of adsorbent for the development of purification process for biomolecules is crucial due to the requirement of large number of binding sites and adsorption area. Considering this, porous structure with high charge density is selected as an adsorbent for macromolecule purification. Such selection may provide high static binding capacity but causes loss of separation performance due to improper porosity of adsorbent in comparison to solute sizes involved. To address this problem for the screening of adsorbent, this work reports adsorbent selection procedure on the basis of adsorbent pore diameter (d p), solute hydrodynamic dimensions (RH), and flow velocity in support of binding capacity. Towards that end, this study evaluated the pore accessibility performance of varying characteristics adsorbents using tracers like acetone, lysozyme, and bovine serum albumin (BSA) by designing nonbinding conditions. All screened adsorbents showed certain loss of total surface area depending on the solute dimensions and pore size. Sepharose type adsorbents showed accessible area loss up to 25% for lysozyme and 50% for BSA. Sepabeads type showed 30% loss, while macroporous UNO type showed only 7% loss of surface area for lysozyme. The study correlates accessibility with size ratio β (d p/RH). The value of β > 38 is found to be required for the accessibility of total pore area and optimum separation performance of ion exchangers investigated. Accessibility and β provide useful information for the selection of suitable adsorbent for the purification of macromolecules.

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Authors: Aida Begic, Ana Djuric, Borko Gobeljic, Ivana Stevanovic, Vera Lukic, Ivan Stanojevic, Milica Ninkovic, Luciano Saso, Danilo Vojvodic and Mirjana Djukic

The aim of our work was to optimize and apply simple high-performance liquid chromatography method with ultraviolet detection (HPLC—UV) for simultaneous determination of reduced (GSH) and oxidized (GSSG) glutathione in biological matrix (specifically, the rat liver tissue was used herein), since the ratio between oxidized and reduced glutathione forms (GSSG—GSH) has been recognized as an important biological marker of oxidatively depleted GSH in oxidative stress (OS)-associated diseases and poisonings. An isocratic chromatographic separation of GSH and GSSG (2.8 min and 6.3 min, respectively) was performed with the mobile phase consisted of sodium perchlorate solution (pH adjusted to 2.8) at flow rate of 1 mL min−1, detection set at 215 nm, and column temperature of 40 °C. The method offers short run time, linearity in the range of 0.01—200 μM concentration for both compounds (R 2 = 1), low limits of detection and quantification (GSH: 0.18 μM and 0.56 μM, GSSG: 0.52 μM and 1.58 μM, respectively), precision, accuracy (bias < 2%), and high reproducibility.

Through suitable sample handling, an overestimation of GSSG was prevented. High recovery (>99%) was achieved. The method was successfully applied for the analysis of GSH and GSSG in liver homogenates of Wistar rats intraperitoneally exposed to cadmium (Cd) (1 mg kg−1 CdCl2/21 days). Regardless of other Cd-mediated hepatotoxicity mechanisms, herein, we have exclusively interpreted/emphasized oxidative GSH depletion.

The presented method is acceptable for a routine analysis of GSH and GSSG in biological matrix, while the calculated ratio GSSG—GSH is considered as a valuable OS marker.

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Authors: Gui-Hua Gu, Da-Jian Yang, Shi-Yun Wang, Wei Zeng, Wei Wang and Jing-Song Yuan

A high-performance liquid chromatography—diode-array detection method was developed and validated to determine simultaneously eleven major alkaloids in Corydalis decumbens (Thunb.) Pers. The alkaloids detected were corlumidine, protopine, coptisine, tetrahydrojatrorrhizine, palmatine, berberine, sanguinarine, papaverine hydrochloride, tetrahydropalmatine, bicuculline, and corydaline. Chromatographic separation was achieved using a C-18 column with a mobile phase composed of A (0.2% acetic acid solution, adjusted with triethylamine to pH 5.0) and B (acetonitrile), with stepwise gradient elution. Ultraviolet diode-array detection was used; chromatograms were examined at the wavelength of 280 nm. The regression equations showed a good linear relationship between the peak area of each marker and concentration (r = 0.9994–0.9999). The recovery values ranged between 93.66% and 100.54%. The method was fully validated with respect to detection and quantification limits, precision, reproducibility, and accuracy. The described high-performance liquid chromatography (HPLC) method was successfully used for the differentiation and quantification of the eleven major alkaloids in C. decumbens (Thunb.) Pers. and can be considered an effective procedure for the analyses of this important class of natural compounds.

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This paper explores the high-performance thin-layer chromatographic (HPTLC) fingerprinting of non-sugar constituents for the authentication of honeys using highly antibacterial Jarrah (Eucalyptus marginata) and Marri (Corymbia calophylla) honeys sourced from Western Australia, different Leptospermum-derived Manuka honeys, and a typical table honey from an undisclosed floral source as test samples. As is demonstrated in this study, using HPTLC fingerprinting, it is possible to define differences in botanical origin as the honey fingerprints exhibit a unique profile of bands (i.e., R f values, color) and peak profiles (i.e., R f and peak intensity values, peak intensity ratios) that differ distinctly from each other. The identification of patterns of common bands among honeys derived from the same floral source as authentication tool is possible. Further, slight differences among honeys from the same botanical origin might be due to age, processing, or regional factors. The HPTLC analysis of two differently aged Jarrah honeys of the same supplier indicates also that future closer investigation of intraspecies differences might assist in developing HPTLC-supported quality control tools.

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Oldenlandia corymbosa Linn. (Rubiaceae) is an important herb traditionally used as a febrifuge and liver tonic. In this study, a high-performance thin-layer chromatography (HPTLC) method has been established for the quantification of four bioactive markers, oleanolic acid (OA), ursolic acid (UA), lupeol (LU), and stigmasterol (ST), in the whole plant of O. corymbosa. Separation was achieved on silica gel 60 F254 HPTLC plates using hexane-ethyl acetate-methanol (8.2:1.8:0.5, v/v) for oleanolic acid and ursolic acid; and toluene-methanol (9.4:0.6, v/v) for lupeol and stigmasterol as the mobile phases. The quantitation of the four markers was carried out using the densitometric scanning at 540 nm after derivatization using sulfuric acid reagent. The linear regression analysis data for the calibration plots showed a good linear relationship (r 2 = 0.9831–0.9979) in the concentration range of 1200–4200 ng for oleanolic acid, 400–1400 ng for ursolic acid, 100–500 ng for lupeol, and 500–2500 ng per spot for stigmasterol with respect to area. The method was validated for linearity, inter-day precision, intra-day precision, repeatability, accuracy, specificity, limit of detection, and limit of quantification. The average recoveries for oleanolic acid, ursolic acid, lupeol, and stigmasterol were 98.77 to 99.12%, indicating the good reproducibility. Stigmasterol 1.19 ± 0.04% w/w was present at high concentration, and oleanolic acid 0.012 ± 0.006% w/w was present at low concentration in the whole plant powder. The proposed HPTLC method was found to be simple, precise, sensitive, accurate, reproducible, and robust.

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Author: Bernd Spangenberg
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Plumbago zeylanica L. (PZ) is a significant medicinal plant in Ayurveda, so is used for the treatment of various disorders. The main active part of this plant is the root, and due to its inherent uses, it has been exploited hence becoming an endangered species. Dyerophytum indicum (Gibbs ex Wight) Kuntze (DI), mainly considered as a substitute of PZ, is also an important folklore medicine, used in many health problems. Both plants are much similar in their physical as well as chemical properties. However, an effective validation is required before declaration of substitution. In the present study, quantitative and qualitative estimations were performed on both plants with the help of modern analytical techniques. Simultaneous high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) and quantitative determinations of β-sitosterol have been performed for comparing both plants, i.e., PZ and DI. HPTLC fingerprinting analysis was also performed comparatively in different plant parts of PZ and DI. Successive extracts from different plant parts were evaluated for TLC separation profile of secondary metabolites. A comparative polyphenolic content- and antioxidant screening was evaluated to check the free radical scavenging effect of both plants (leaf, stem, and root) in comparison with the standards gallic and ascorbic acid.

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Authors: Veena Dixit, Saba Irshad, Harsh Singh, Priyanka Agnihotri, Tariq Husain and Sayyada Khatoon

This study was designed to develop a simple, sensitive, selective, and precise high-performance thin-layer chromatography (HPTLC) fingerprint and quantitative estimation method for the analysis of three phenolic compounds from nine Leucas species. The developed HPTLC method was validated according to the International Conference on Harmonization guidelines. The method permits reliable quantification of one important phenolic acid (gallic acid) and two hydroxycinnamic acids (caffeic and ferulic acids) in 50% hydroethanolic extracts on silica gel with toluene—ethyl acetate—formic acid 8:2:1 (v/v) as the mobile phase. The system showed good resolution and separation of caffeic, ferulic, and gallic acids (at R f values 0.48, 0.60, and 0.30, respectively) from the other constituents of the extract. Densitometric scanning was done at 300 nm in absorbance mode. All the results obtained by the developed method were statistically compared for validation parameters, for accuracy and good precision. Caffeic, ferulic, and gallic acids were estimated in all the aforesaid nine Leucas species, but the quantity varied from species to species. Further, these phenolics were reported from the aforesaid Leucas species for the first time, except for Leucas lanata and Leucas urticifolia. However, Leucas biflora, Leucas decemdentata, and Leucas stricta were documented for their chemical constituents for the first time. The proposed HPTLC method can be used for routine quality testing of Leucas species.

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Trikatu Churna is an important formulation in Ayurveda — the Traditional System of Indian Medicine. It consists of fine powders of fruits of Piper nigrum L., Piper longum L., and rhizomes of Zingiber officinale Roscoe in equal proportions. Piperine, present in both P. nigrum and P. longum, is considered to be responsible for the improvement of digestion and bioavailability enhancement of many medicaments. Gingerols and 6-shogaol are key chemical molecules in Z. officinale. Piperlongumine is present in P. longum fruits but absent in the fruits of P. nigrum. We report a validated high-performance thin-layer chromatography (HPTLC) method for the determination of piperine, piperlongumine, and 6-shogaol in these herbs and in Trikatu Churna. Piperine, piperlongumine, and 6-shogaol resolved well in n-hexane—ethyl acetate (8:2) on precoated silica gel 60 F254 plates. The absorption maxima for piperine, piperlongumine, and 6-shogaol were found to be 327, 272 and 235 nm, respectively. Linearity for the corresponding markers was observed between 0.1–0.5, 0.2–1.0, and 0.1–1.6 μg spot−1, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 28 and 100, 56 and 200, and 32 and 100 ng for piperine, piperlongumine, and 6-shogaol, respectively. Recovery experiments showed 99.6%, 99.5%, and 99.7% recoveries for piperine, piperlongumine, and 6-shogaol, respectively. P. nigrum fruits from Delhi and Ahmedabad had around 2.0% w/w piperine, while fruits of P. longum from these markets were analyzed for 0.8% and 0.6% w/w piperine. Piperlongumine was not found in both samples of P. nigrum, while the fruits of P. longum had 0.36% and 0.26% w/w piperlongumine. Z. officinale from Delhi had 0.19% w/w of 6-shogaol as against 0.16% w/w found in the sample from Ahmedabad. Plant materials procured from Delhi were employed for the preparation of Trikatu Churna which showed 96.5%, 95%, and 103% w/w of the expected values of piperine, piperlongumine, and 6-shogaol, respectively. The present method is simple, reproducible, and reliable which can be applied for the routine analysis of Trikatu Churna and its ingredients in polyherbal formulations.

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Authors: Qasimullah, Ali Mohammad and Mahfoozurrahman Khan

This review encapsulates the work which appeared in the literature during 1995–2015 on the use of microemulsion as the mobile phase in the analysis of inorganic anions and organic compounds by thin-layer chromatography (TLC). Among anionic, cationic, and non-ionic surfactants used as one of the components of oil-in-water (O/W) and water-in-oil (W/O) microemulsions, sodium dodecyl sulfate (SDS) (anionic surfactant) has been found the most effective for the analysis and separation of different compounds. Compared to the work performed with the use of W/O microemulsion, little work has been reported on use of O/W microemulsion in the TLC—high-performance thin-layer chromatography (HPTLC) analysis of organic compounds. In contrary to TLC, more work has been done on use of O/W microemulsion in high-performance liquid chromatography (HPLC). Out of the sorbent phases, silica gel in combination with microemulsion eluent has been favorable for realizing analytically useful separations. Classification of microemulsions and surfactants is also discussed in the present review.

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Kutkin, a mixture of two iridoid glycosides, viz., picrosides I and II, is a major active constituent of Picrorhiza kurroa (family: Scrophulariaceae). P. kurroa is reported to be effective in many ailments, viz., liver disorders, cancer, asthma, and inflammation. Various herbal and Ayurvedic preparations containing P. kurroa are available on the market. In these formulations, quality is not maintained in the absence of quick, efficient, and economic quantification methods for active markers. In the present study, a high-performance thin-layer chromatographic (HPTLC)—densitometric method was developed for the simultaneous quantification of picrosides I and II using kutkin from P. kurroa crude drug, P. kurroa extract, and its marketed formulations, viz., Picrolax capsules and Picrolax suspension. The method was validated as per the International Conference on Harmonization (ICH) guidelines. The samples were prepared and applied in triplicate on HPTLC plates. The plates were developed using the mobile phase ethyl acetate—methanol—glacial acetic acid (5:1:0.3, v/v) and scanned at a wavelength of 270 nm. The active contents of picrosides I and II were estimated for P. kurroa crude drug (2.62 ± 0.02% w/w and 1.23 ± 0.01% w/w), P. kurroa extract (8.83 ± 0.36% w/w and 6.34 ± 0.13% w/w), Picrolax suspension (0.13 ± 0.003% w/v and 0.04 ± 0.002% w/v), and Picrolax capsules (2.84 ± 0.02% w/w and 1.11 ± 0.04% w/w). The HPTLC—densitometric method, developed for the quantification of picrosides I and II, was found to be simple, precise, specific, sensitive, and accurate, hence it can be used in the routine quality control of raw materials and finished products.

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Rapid and sensitive thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC)—densitometry methods were used to separate, identify and quantify luliconazole (LUL), a new azole antifungal, in bulk and pharmaceutical dosage form. The proposed method can be used as a stability-indicating assay for the determination of LUL in the presence of its degradation products under forced degradation conditions (alkaline, acidic, oxidative, thermal and photolytic degradation). Complete separation was achieved by TLC and HPTLC on silica gel F254 plates with the solvent system toluene—isopropanol—ammonia (90:10:0.5, v/v). The chromatographic bands were visualized under short-wave ultraviolet (UV) light, and the amount of LUL was determined by scanning densitometry at 297 nm using peak area. The linear ranges were 1–24 and 0.8–6 μg band−1 with mean percentage recoveries of 99.84% ± 0.623 and 99.98% ± 1.405 for TLC and HPTLC, respectively. The methods were validated according to the International Conference on Harmonization (ICH) guidelines. The statistical analysis of the results revealed high accuracy and good precision. The suggested procedures could be used as a stability-indicating assay for the determination of LUL in drug substance and drug products in the presence of its degradation products.

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Response surface methodology (RSM) was used to optimize solid– liquid ultrasonic-assisted extraction (UAE) conditions for the maximization of the stigmasterol content from an Ayurvedic plant Tecomella undulata (T. undulata) bark. The Box—Behnken design (BBD), form of RSM, was employed for the optimization of ultrasonic extraction parameters, viz., temperature (°C), drug-to-solvent ratio (mg/10 mL), and time (min). Quantification of stigmasterol was performed using high-performance thin-layer chromatography in visible range (HPTLC–vis). HPTLC analysis of stigmasterol was carried out in the absorbance mode at 510 nm using toluene—ethyl acetate—formic acid (8.0:1.5:0.5, v/v) as the solvent system. This system was found to give compact spots for stigmasterol at R f 0.44 ± 0.01. The optimal UAE processing parameters were the following: extraction time, 46 min; temperature, 50°C; and drug-to-solvent ratio, 528 mg/10 mL, with stigmasterol yield of 2.45 ± 0.073%. This study proves that the use of BBD for the optimization of UAE process provides more accuracy than single factorial optimization. The optimized UAE was a more efficient technique over conventional Soxhlet extraction (CSE) due to the higher stigmasterol content along with the low ingredient and time consumption. To the best of the authors’ knowledge, no studies have been published previously addressing specifically the optimization of ultrasonic extraction of stigmasterol from T. undulata bark using BBD.

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