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Introduction The aim of this work is to study the thermal behavior in the medium–high temperature range of the sulfur containing amino acid l -cysteine and its corresponding dimer l -cystine, which is composed of two l

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The enantiomers of serine have been separated after pre-column derivatization with ortho-phthaldialdehyde (OPA) and N-tert-butyloxycarbonyl-l-cysteine (Boc). Analysis of the enantiomers of amino acids after pre-column derivatization with OPA-Boc has been reported in the literature but no critical evaluation has been carried out. In this study, decomposition of the diastereomers, effect of the sample pH, and amount of derivatization agent were studied; the half life of the decomposition was also determined. The method was used for analysis of D and l-serine from three different areas of rat brain (the striatum, prefrontal cortex, and cerebellum).

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Dithiocarbamates fungicides (DTCs) are worldwidely used fungicides. Residue analytical methods on DTCs are usually based on headspace gas chromatography, which are not much stable and precise. In this study, a specific, simple and reliable method for determining DTCs fungicides residues was optimized and validated. The DTCs in foods and soils were extracted with an alkaline solution of EDTA and l-cysteine, followed by pH adjusting and methyl derivatization in methyl iodine solution. The organic layer of the reactants was separated, concentrated under vacuum and reconstructed in acetonitrile. DTCs residues were eluted on a C18 column and detected by HPLC-DAD at 272 nm. The S-alkyl derivatives of thiram, mancozeb and propineb were separated at different retention times. At fortified levels of 0.05 mg/kg to 2 mg/kg (residue expressed as CS2, in mg/kg, the same below), it is found that recoveries for DTCs spiked in apple, cucumber, tomato, rice and soil samples ranged from 70.8% to 105.3%, with relative standard deviations (RSD) from 0.6% to 13.7%. Limits of detection (LODs) and quantification (LOQs) ranged from 0.003 to 0.026 mg/kg and from 0.011 to 0.105 mg/kg for various foods and soils. This method was also applied to real sample tests.

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European Journal of Microbiology and Immunology
Authors: Kouassi N’Guessan, Timothée Ouassa, Anna S. Dean, Riccardo Alagna, Guy Damien Adagra, Valeri Ibode, Daniela M. Cirillo, and Jacquemin Kouakou

. Sputum samples were decontaminated by the standard N -acetyl-l-cysteine–4% NaOH procedure. The supernatant was discarded, and the pellet was resuspended with sterile phosphate buffer to a final volume of 2 mL. This was inoculated into one BACTEC

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. , and Maity , A. ( 2018 ). l-cysteine doped polypyrrole (PPy@L-Cyst): a super adsorbent for the rapid removal of Hg+2 and efficient catalytic activity of the spent adsorbent for reuse

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