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Chemical engineering is an engineering branch that deals with the chemical production and manufacture of products that undergo chemical processes. This includes equipment design, creating systems and processes to refine raw material, as well as mixing, compounding, and processing chemicals to create products.

Chemistry and Chemical Engineering

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Abstract

Residues of the fungicides difenoconazole, propiconazole, cyflufenamid, and mandipropamid were determined in tomato fruit using acetonitrile for extraction and LC-MS/MS for quantification. Validation criteria include linearity range, the limit of detection (LOD) and limit of quantitation (LOQ), accuracy in terms of precision and trueness, and matrix effect were studied. The recovery rates of the method ranged from 91.8 to 106.3%. The precision of the method in terms of repeatability at one day (RSDr) and between three days (RSDR) ranged from 2.8 to 6.4% and from 4.3 to 7.6%, respectively, with good trueness from 92.2 to 96.4%. Matrix effects (suppression effects) ranged from 3.8% to 11.1%. The validated method was used to evaluate the dissipation kinetics of three different premix formulations: 30% EC (15% difenoconazole + 15% propiconazole), 14% DC (12.5% difenoconazole + 1.5% cyflufenamid), and 50% SC (25% difenoconazole + 25% mandipropamid) used on field tomatoes in Egypt. A first-order kinetic equation best describes residue dissipation. The calculated half-lives of difenoconazole, propiconazole, cyflufenamid, and mandipropamid were 2.01–2.27, 1.89, 1.97, and 1.71 days, respectively. The dissipation rate of difenoconazole did not differ significantly in the three premix formulations. Mandipropamid also dissipated faster compared to the other fungicides tested. The chronic dietary risk assessment results showed a minimal risk to adult Egyptian consumers. Waiting periods were advised for the safe consumption of tomatoes treated with the tested premix formulations.

Open access

Az azbesztszálak kimutatására szolgáló vizsgálatok középpontjában a levegőszennyezettségi értékek álltak, de a 21. században felmerült az igény a problémakör kiterjesztésére. Az elmúlt években megjelent nemzetközi tudományos szakirodalmak megcáfolták az évtizedeken át fennálló feltételezést, miszerint az azbeszt csupán a levegőterheltség révén vált ki kockázatot. Vízminőségi és talajminőségi kutatások által teret nyert az azbesztszálak, különösen a krizotilszálak alternatív transzportútjainak vizsgálatát célzó kutatásterület. Annak ellenére, hogy mind a települési, mind pedig a mezőgazdasági vízgazdálkodás potenciálisan érintett a krizotil-azbeszt jelenléte kapcsán, nincs nemzetközi szinten egységes és elfogadott módszer vagy küszöbérték az egyes vízforrások biztonságára vonatkozóan. A kutatások nyilvánvaló korlátja, hogy csekély mennyiségű és minőségű tudás érhető el. Az azbesztszálak megjelenése az egyes vízbázisokban jelentősen megváltoztatja mind a mezőgazdasági, mind a települési vízgazdálkodás környezeti hatásoknak való kitettségéről alkotott eddigi ismereteinket. Az öntözővizzel és a gyűjtött csapadékkal kijuttatott azbesztszálak hatásainak palettája mára túlhaladta a humán- és állategészségügyi hatásokat, immár figyelmet kell fordítani a vegetációs hatásokra is. Annak érdekében, hogy nagyobb betekintést nyerjünk az azbeszttoxicitás növényekre gyakorolt hatásaiba, sokkal több tudományos eredményre van szükség.

Jelen összefoglaló tanulmányban bemutatjuk az azbeszt, különös tekintettel a krizotil azbeszt legfontosabb tulajdonságait, humán-, állat- és növényegészségügyi kockázatait. Rávilágítunk arra, hogy ismereteink rendkívül hiányosak, valamint felhívjuk a figyelmet a települési és mezőgazdasági vízgazdálkodás érintettségének egyes faktoraira, közvetlen és közvetett kockázati tényezőire, valamint arra, hogy ezek miként hatnak az élőlényekre, kiemelt tekintettel a növényekre.

Open access
Agrokémia és Talajtan
Authors:
Andrea Balláné Kovács
and
János Kátai
Restricted access

Abstract

A novel doxorubicin hydrochloride liposome injection was prepared to reduce toxicity and side effects, as well as extend plasma half-life in the treatment of breast cancer. In this study, a rapid and sensitive bioanalytical method was developed and validated to characterize the pharmacokinetic profile of total and free doxorubicin in plasma of 3 Chinese patients after intravenous infusion of this injection. Plasma samples were prepared by protein precipitation for the determination of total doxorubicin, while solid phase extraction was used to determine free doxorubicin. After plasma sample pre-treatment, total and free concentrations were quantified individually using a validated LC-MS/MS method. The calibration curves were found to be linear in the range of 0.20–500.0 ng mL−1 for total doxorubicin and in the range of 1.00–1,000 ng mL−1 for free doxorubicin. The free concentrations in plasma were only one sixth to one quarter of the total levels. Liposomal doxorubicin had a longer apparent half-life (>50 h) than the non-targeted drug (<10 h) reported in the reference. and a lower volume of distribution. This novel injectable formulation steadily released free doxorubicin from liposomes over a long period of time to reduce cardiac toxicity and side effects, while ensuring a clinical curative effect.

Open access

Abstract

In this work, a UPLC-MS/MS assay was established for the determination of morphine, codeine, thebaine, papaverine and noscapine in rat plasma. ACQUITY UPLC BEH C18 column was employed for chromatographic separation with the mobile phase comprised acetonitrile-10 mmol L−1 ammonium acetate aqueous solution (0.05% aqueous ammonia) using gradient elution. Midazolam was used as internal standard (IS). Electrospray ionization (ESI) in positive-ion mode with reaction monitoring (MRM) was used for quantitative analysis. The calibration curves for morphine, codeine, thebaine, papaverine and noscapine demonstrated good linearity (r > 0.995) in the range of 5–500 ng mL−1 for morphine and codeine, and 1–100 ng mL−1 for thebaine, papaverine and noscapine. The intra-day and inter-day precisions of morphine, codeine, thebaine, papaverine and noscapine were within 15%, the intra-day and inter-day accuracies were 89–114%, the recovery was better than 65%, and the matrix effects were 96–112%. The developed UPLC-MS/MS assay was successfully applied in the pharmacokinetics of papaverine and noscapine.

Open access

Abstract

In this study, a UPLC-MS/MS method was developed for determination of pancratistatin in the mouse blood, and the pharmacokinetics of pancratistatin in mice after intravenous (5 mg kg−1) and intragastric (15 mg kg−1) administration was studied. HSS T3 column was used for separation with mobile phases of acetonitrile and 0.1% formic acid using gradient elution procedure. The blood sample was treated by protein precipitant with acetonitrile, midazolam was used as internal standard (IS). Multiple reaction monitoring mode (MRM) was used for quantitative analysis, m/z 326.2→83.8 for pancratistatin and m/z 326.2→291.4 for IS in electrospray (ESI) positive interface. It showed a good linear in the range of 10–4,000 ng mL−1 (r > 0.998); the intra-day and inter-day precision was <15%, and the accuracy was 93%–105%. The recovery was better than 82%, and the matrix effect was 94%–105%. The developed UPLC-MS/MS method was fast, selective, and suitable for the pharmacokinetics of pancratistatin in mice.

Open access

Abstract

The rapid technological development that is still taking place today, with increasingly interconnected IT tools, is introducing dramatic changes. The development of computer programs is rapidly transforming traditional processes and the systems that support them. It is therefore natural that the fourth industrial revolution (Industry 4.0) and its impact on Hungarian companies is one of the key topics of our time. We conducted an exploratory quantitative survey, asking 140 managers of Hungarian small, medium and large enterprises about their current situation in the context of Industry 4.0. We sought to find out to what extent the specific R&D and innovation potential of Industry 4.0 is accepted, and whether it has already been introduced in the companies. On a qualitative side, 2 case studies and 3 interviews were conducted, in which structured interviews were used to further explore the issue. We aimed to find out where SMEs stood in terms of digital preparedness and what advantages, possible disadvantages, and goals they managed to identify. Our research showed that an increasing number of companies have already decided to take the first steps towards industrial digitalisation, which will completely transform their internal processes.

Open access