نتایج جستجو برای: BSTFA
تعداد نتایج: 65 فیلتر نتایج به سال:
N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (El) and 17alpha-ethinylestradiol (EE2). In this study, three trimethylsilyl (TMS) steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl E1, were observed during the der...
A method for detecting mustard gas degradation products thiodiglycol (TDG) and thiodiglycol sulfoxide (TDGO) in water and sediment samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) after derivatization with 1-(trifluoroacetyl)imidazole (TFAI) was described. Selected reaction monitoring mode (SRM) of tandem mass spectrometry was developed for analysis of TDG and TDGO derivativ...
For the detection of rare phospholipid, phosphatidylethanol (PEt), GC-MS analysis method was adopted for the detection of derivatization products of PEt by N,O-bis (trimethylsilyl) trifluroacetamide (BSTFA). A re-structured molecule derived from PEt, ethyl bis (trimethylsilyl)-phosphate was found from search of Wiley database. This molecule can be used as a marker for PEt analysis. The molecula...
Gas chromatography–mass spectrometry (GC–MS) has been investigated for identification of bisphenol A (BPA) at ppb levels in biological samples. Initially a limit of detection (LOD) of 600 ppb BPA was established by direct selected-ion monitoring (SIM) GC–MS. Next, standard solutions of BPA and extracts of powdered milk were derivatized with two different reagents – N,O-bis-(trimethylsilyl)trifl...
are certain that a number of synthetic chemicals act like hormones (e.g. estrogen) and interact with the human hormone system. Scientists also agree that the magnitude of the problem (including human exposure) is uncertain. Therefore, the analysis of phenols in natural wastewater and soils is of prime importance to environmental organizations due to their frequent occurrence in a wide range of ...
Fecal sterol has been proposed as a chemical indicator of human fecal pollution even when fecal coliform populations have diminished due to water chlorination or toxic effects of industrial effluents. This paper describes an improved derivatization procedure for simultaneous determination of four fecal sterols including coprostanol, epicholestanol, cholesterol and cholestanol using gas chromato...
RATIONALE To provide a simple one-step derivatization procedure for the analysis of a wide variety of amino acids in human hair by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatization is already widely used outside the IRMS community, is applicable to a variety of functional groups, and provides products that...
..................................................................................................................................................v INTRODUCTION....................................................................................................................................1 1. Gastrointestinal tract (GI)............................................................................
The aim of this study was the development and validation of a new method for carbohydrates analyses obtained from woody biomass, as a step of bioethanol production. In this study, we have quantified carbohydrates in wood by gas chromatography (GC) after derivatization. Quantification of carbohydrates was made by liquid-liquid extraction, oximation and silylation and, finally, analysis by gas ch...
A sensitive and specific gas chromatographic-mass spectrometric method for the determination of clenbuterol in urine and liver samples is described. Prepared for confirmatory purposes, this method includes solid phase extraction for clean up of biological samples, derivatization and analysis of the clenbuterol derivatives in the selected ion monitoring mode. During the studies, six derivatizati...
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