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Abstract

Atractylodis macrocephalae rhizome (AMR) belongs to medicine food homology. Its' clinical application of invigorating the spleen-stomach of AMR was applied to various diseases. In this research, a UPLC-QTOF-MS method was developed for qualitative and quantitative analysis of AMR, simultaneously. A Waters Acquity BEH C18 column (2.1 mm × 100 mm, 1.7 μm particle size) was used for separation of AMR multi-components. The column was eluted with a mobile phase of 0.1% formic acid-water and 0.1% formic acid-acetonitrile. Electron spray ionization with positive-ion mode and external standard method was utilized for quantifying the nine analytes in AMR. Constituents of AMR were scanned by UPLC-QTOF-MS and then identified by mass fragments and chromatographic information compared with the published literature and reference standards. Under positive mode, a total of 61 chemical compositions including 16 terpenoids, 8 polyacetylenes, 6 aromatics, 5 flavonoids, 5 coumarins, 5 organic acids, 4 amino acids, 3 fatty acids, 3 aliphatics, 2 steroids, and 2 alkenes, a nucleoside and an aldehyde were identified. Simultaneously, the contents of three amino acids (L-tyrosine, L-phenylalanine, and L-tryptophan), three sesquiterpenoids (atractylenolide Ⅲ, atractylenolide Ⅱ, and atractylenolide Ⅰ), a flavonoid (rutin), an organic acid (ferulic acid), and a pentacyclic triterpenoid (oleanolic acid) were determined in seventeen AMR batches. Amino acids and triterpenoid were quantified for the first time in AMR. The UPLC-QTOF-MS method developed in this article was reliable, practical, and useful for qualitative and quantitative evaluation of AMR multi-components.

Open access

Abstract

Coloring agents in foods and drinks have been popular for centuries. This study aims to analyze the presence of ten synthetic colors (namely, (allura red (E129), amaranth (E123), sunset yellow (E110), tetrazine (E102), fast green (E143), ponceau 4R (New Coccine) (E124), erythrosin B (E127), brilliant blue FCF (E133), brilliant black (E151) and carmoisine (E122))) in food and drink samples using ultra-high-performance liquid chromatography diode array detection (UHPLC-DAD). The present analytical method was carried out using Agilent Poroshell 120 HPH-C18 column, 3 × 100 mm, 2.7 µm, and a mobile phase consisting of 10 mM Na2HPO4, pH 7, mixed with methanol as a time-increment gradient solution until the time was 20 min, then decreased with time until the time was 26 min. The pH was set by orthophosphoric acid at 7 and 5 μL injection volume, 0.50 mL flow rate, and the elution systems were monitored at 428 nm for E102, 518 nm for E124, E110, E129, E122, 530 nm for E151, E127, 622 nm for E143, and E133, respectively. The limit of detection and quantification for all colors ranged from 0.017 to 0.025 and 0.057 and 0.082 mg L−1, respectively. The correlation coefficient values ranged between 0.9991 and 1.0. The selectivity of the assay revealed no interference from other components in the analyzed samples. The percent recovery and precision (intra- and inter-day) of the spiked samples were within the acceptable limits of the ICH guidelines. Five analytical parameters were employed, and the results showed a new, novel, and robust method according to ICH guidelines for analyzing these colors. While most of the investigated food and drinks fell within the accepted range, some fell outside. The current sample preparation and analytical methods are comprehensive and universal for extracting and measuring synthetic colors in various food and drink samples.

Open access

Talajnedvesség-tartalom mérése földradarral (GPR) és mezőgazdasági alkalmazhatóságának lehetőségei

Soil water content measurements with ground penetrating radar (GPR) and its application possibilities in the agriculture

Agrokémia és Talajtan
Authors:
András Herceg
and
Csaba Tóth

A talajnedvesség-tartalom variabilitásának mérését jelentősen megnehezíti a talaj heterogenitása és a környezeti változatosság. Jelenleg még nem fejlesztettek ki olyan univerzális módszert, amely a magas vagy alacsony talajnedvesség-zónák szántóföldi léptékű feltérképezésére alkalmas úgy, hogy a talajnak és a talajnedvesség áramlásának teljes zavarásmentességét nagy mélységben is biztosítja.

A talajnedvesség-mérés részben (talajkapcsolt), vagy teljesen roncsolásmentes (levegőkapcsolt) lehetőségét biztosítja a földradar (GPR), amely nagy felbontást és jelentős behatolási mélységet biztosít a közepes léptékű talajnedvesség meghatározáshoz, így hiánypótló technikát jelent a kisléptékű pontszerű és a nagyléptékű távérzékelt mérési technikák közötti metodikai hiány kitöltésére. Emellett jobb időhatékonyággal alkalmazható más roncsolásos és roncsolásmentes eljárásokkal összevetve.

A talajradart sikeresen alkalmazták a talajnedvesség-meghatározásra, de hidrológiai vizsgálatokban történő alkalmazásának nagy potenciálja ellenére nem minden körülmény között működik optimálisan. Felhasználhatósága többnyire olyan területekre korlátozódik, ahol viszonylag alacsony az elektromos vezetőképesség (az elektromágneses hullám gyenge csillapodására való tekintettel). Ezen túlmenően egyes talajradar módszerek működésének alapfeltétele a jól azonosítható és folyamatos jelvisszaverődés, továbbá a dielektromos állandó tekintetében a földradar-rendszerek térben folyamatos felszín alatti kontrasztot igényelnek.

A talajnedvesség és annak áramlása kulcsparaméter a mezőgazdaság különböző területein. A talajnedvesség (és a talajvíz) látja el a növényeket, ami elengedhetetlen feltétele a növények fejlődésének. Ennélfogva a talaj nedvességtartalmának, eloszlásának, áramlásának, valamint a beszivárgás sajátosságainak alapos és lokális ismerete az öntözés hatékony megvalósításának alapköve, különösen a félszáraz és száraz éghajlatú területeken.

A talajradar mérési alapjaival, valamint hasznosítási lehetőségeivel összefüggésben az elsősorban nemzetközi szakirodalmat összegezve megállapítható, hogy a GPR előnyös mérőeszköz lehet, amely segíthet a talaj nedvességeloszlásának feltérképezésében, tekintettel a beszivárgásra, a párolgás és a növényi vízfelvétel okozta vízveszteségre is. Következésképpen mezőgazdasági felhasználhatósága lehetséges.

A talajradar hasznos része lehet a „Smart farming”-nak (intelligens gazdálkodás), segítséget nyújthat a talajban elhelyezett talajnedvesség-mérő szenzorok kijelölésében. Különösen, ha a közelmúltban megjelent új, szimultán többeltolásos és többcsatornás (SiMoc) GPR rendszerre asszociálunk, amely gyors talajprofil-feltérképezést tesz lehetővé a hét vevőegységével, de a hagyományos egycsatornás GPR sebességével.

Ha a teljes roncsolásmentesség a cél, úgy a drónra szerelt levegőkapcsolt GPR-ek nyújthatnak lehetőséget. Megjegyzendő azonban, hogy a talaj-levegő határfelületen jelentkező szignifikáns jelcsillapodás (hullámszóródás) következtében a feltárási mélység jelentősen csökken.

A földradar végső soron mérési alapul szolgálhat a hatékony (precíziós) öntözési gazdálkodás kialakításához, és a megfelelő vízfelhasználási hatékonyságot biztosítva járulhat hozzá a precíziós mezőgazdasági programok megvalósításához.

Open access

Abstract

In order to improve the thermal performance of heat exchangers and air collectors, we insert various forms of artificial roughness, known as ribs, into the useful duct. These ribs promote the creation of turbulent flows and enhance heat transfer by conduction, convection and radiation.

However, the introduction of these ribs leads to an increase in pressure drop, requiring higher mechanical power to pump the heat transfer fluid. This experimental study focuses on estimating, using empirical approaches, the pressure losses induced by rectangular ribs with an inclined top. The ribs are made from 0.4 mm galvanized sheet steel.

An experimental set-up was designed to measure the head losses generated by the ribs, from the point of entry to the point of exit from the useful duct. Using the dimensional analysis method, correlations were established to evaluate head losses as a function of flow regime and rib geometry and configuration (including different geometries for rib arrangement over the configuration area).

Open access
Acta Chromatographica
Authors:
Fan Chen
,
Ziyue Wang
,
Xiaoyun Xia
,
Wanhang Wang
,
Yizhe Ma
,
Xiuwei Shen
,
Xuzhao Zhou
, and
Congcong Wen

Abstract

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of monocrotaline and usaramine in rat plasma, to study the plasma drug concentration and pharmacokinetics, and to calculate the absolute bioavailability. The plasma was treated with acetonitrile and methanol (9:1, v/v) protein precipitation method. The chromatographic column was UPLC HSS T3 (50 mm × 2.1 mm, 1.7 μm), the mobile phase was methanol-water (containing 0.1% formic acid with 10 mM ammonium acetate in water), and the elution time was 4 min at a flow rate of 0.4 mL min−1. Electrospray ionization (ESI) positive ion mode was used for detection and multiple reaction monitoring (MRM) mode was used for quantitative analysis. Monocrotaline and usaramine were administered sublingual intravenously (iv) 1 mg kg−1 and orally (po) 5 mg kg−1, respectively, with 6 rats in each group, for a total of 24 rats. Then the pharmacokinetic differences in rats were evaluated. For the UPLC-MS/MS method, the calibration curve showed good linearity in the range of 2–2,000 ng mL−1, where r was greater than 0.99. The precision, accuracy, recovery, matrix effect and stability results were all consistent with the requirements of biological sample detection methods. to provide scientific experimental basis for the basic research The bioavailability of monocrotaline and usaramine in rat plasma was calculated, which was 43.5 and 19.5%, respectively.

Open access

Abstract

Silica, as a stationary phase, has low separation efficiency accompanied by overlapping, broadened, and tailed peaks, so it needs to be modified to improve its efficiency. This study aims to develop a silica-based stationary phase modified by tetraethylene glycol (TEG) to separate phenolic compounds. Silica was modified by a chemical bond between silanol groups on the silica surface and TEG through a 3-glycidyloxypropylmethoxysilane reaction. The modified silica was packed into a capillary column and used to separate simple phenolic compounds consisting of phenol, pyrocatechol, and pyrogallol. A sample of 0.2 µL was injected into the capillary liquid chromatography and the mobile phase employed was acetonitrile 98% with a flow rate of 3 μL min−1. Elution was also done isocratically in this process and detection was carried out at a wavelength of 254 nm. The mixture of simple phenolic compounds was successfully separated in less than 7 min. The asymmetry factor and resolution were 1.43–2.12 and 1.72–5.43 respectively. The number of the theoretical plates ranged from 213 to 7,857. Columns containing Si-TEG stationary phase also separate phenolic compounds, which consist of gallic acid, syringic acid, ferulic acid, and caffeic acid. A sample of 0.2 µL was injected into the capillary liquid chromatography and successfully separated the mixture in less than 12 min. The samples were eluted isocratically using a mixture of methanol and 50 mM phosphate buffer pH 2.5 (8:92) with a flow rate of 3 μL min−1. The phenolic acids compounds were detected at a wavelength of 280 nm. The chromatogram showed four separate peaks. The asymmetry factor and resolution were 1.53–1.63 and 1.14–1.74, respectively, but the number of the theoretical plates was low, ranging from 190 to 796.

Open access

Abstract

Pinus merkusii Jungh & De Vries. has become increasingly gathered more attention from researchers because the plant has a range of folk medicinal uses. Heartwood plant is the major source of dehydroabietic acid (DHAA) and abietic acid (AA), which possesses several medicinal properties, such as antiviral, antimicrobial, antiobesity and anti-inflammatory. The research proposed herein a low-cost, fast, specific, uncomplicated, sensitive, precise reverse-phase high-performance liquid chromatography (RP-HPLC). This method was conducted and validated for evaluating an amount of DHAA and AA in ethanol extract and oral spray containing P. merkusii heartwood extract. Additionally, stability and antimicrobial activities against clinically isolated Streptococcus mutans of the oral spray were determined. The separation was achieved on Pursuit 200Å PFP column, 150 × 4.6 mm, particles of 3 µm with a flow rate of 1.0 mL min−1. Methanol and water (70:30 v/v) were used as eluent with an isocratic mode and sample analysis volume was set at 10 µL, at a detection wavelength of 210 and 245 nm. The developed HPLC method for analysis of DHAA and AA showed good linearity with correlation coefficients equal to 1. Moreover, other validation parameters, comprised of accuracy, precision, specificity and detection and quantitation limits of this method displayed excellent reliability, validity and sensitivity. This method could be an interesting alternative for quantitative measurement of P. merkusii heartwood extract, oral spray formulation and other P. merkusii heartwood extract preparations. The result from antibacterial tests suggested that the oral spray containing P. merkusii heartwood extract is able to inhibit the oral pathogens causing dental caries. The oral spray decreased S. mutans population size by about 0.5–2 Log CFU mL−1 at 1–4 h and complete elimination of all bacteria strains within 24 h. This study provides validity for using P. merkusii heartwood extract as an alternative for preventing and treating oral infectious diseases.

Open access

Abstract

In this study, we compile the findings to date on using several cellulose-based materials as adsorbents of potentially toxic elements (PTEs) from wastewater. Furthermore, this review discussed the destiny of PTEs-loaded cellulose-based adsorbents and some sustainable methods for their management, hoping to close the pollution loop.

Open access

Abstract

Mirtazapine is an antidepressant medication used to treat the major depressive disorder in adults. In this study, two different chromatographic methods were developed for the determination of mirtazapine in pharmaceutical products. In the first method, An Extend C18 column (250 × 4.6 mm, 5 μm) was used and the temperature was kept constant at 25 °C. The mobile phase was determined as 0.1% formic acid solution and acetonitrile (80/20, v/v), and isocratic elution was applied. The flow rate of the mobile phase was determined as 1.0 mL min−1 and the injection volume was 20 µL. Detection was performed at 291 nm. using a UV detector. In the second method, ethanol was used as the organic modifier. The only difference between these methods was the organic modifier. All other conditions of the methods were the same. Both chromatographic methods were validated by ICH guidelines for various parameters such as selectivity, linearity, accuracy, precision, detection and quantification limit, and robustness. The determination coefficients of chromatographic methods were greater than 0.999 in the concentration range of 5–30 µg mL−1. of mirtazapine. Later, these chromatographic methods were applied to pharmaceutical formulations. Comparison of the obtained results in terms of means was made using Student's (t) test, and comparisons in terms of standard deviations were made using the Fischer (F) test. It was observed that there was no significant difference between these methods. These two methods were then evaluated using the AGREE-Analytical GREEnness metric software. The chromatographic method using ethanol as an organic modifier has been proposed as an excellent eco-friendly and analyst-friendly alternative for the determination of mirtazapine in pharmaceutical formulations.

Open access

Abstract

It still remains a great challenge to selectively enrich and sensitively quantify the trace volatile organic compounds (VOCs) in real samples with complex matrix. In this study, an integration method combining a selective enrichment medium of reduced graphene oxide (rGO) with a specially designed micro thermal-assisted purge-and-trap sampling device was developed for efficient enrichment and sensitive quantification of trace tobacco VOCs coupling with thermal desorption (TD)-gas chromatography/mass spectrometry (GC/MS). The prepared rGO has been proved to possess excellent enrichment selectivity and capacity for tobacco polar VOCs with the multi-layer structure, good thermal stability and large specific surface area. The specially designed sampling device was efficient and suitable for enriching and sampling trace polar tobacco VOCs coupling with rGO medium. Under the optimized sampling and analytical conditions, the established analytical method could be actually applied for quantification of typical tobacco polar VOCs with the good recoveries of 72.9–128% and the satisfied RSDs of 1.8–19.9% (n = 3). The results suggested that the developed method was selective, sensitive and reliable for enrichment and quantification of trace tobacco polar VOCs.

Open access