نتایج جستجو برای: bstfa

تعداد نتایج: 65  

Journal: :Journal of environmental sciences 2007
Yi-Qi Zhou Zi-Jian Wang Ning Jia

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...

Journal: :Analytical chemistry 2014
Stanisław Popiel Jakub Nawała Daniel Dziedzic Martin Söderström Paula Vanninen

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...

Journal: :Experimental & molecular medicine 2000
C Yon J S Han

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...

2007
K. Szyrwińska A. Kołodziejczak I. Rykowska W. Wasiak J. Lulek

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...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2001
M I Helaleh K Tanaka S Fujii T Korenaga

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 ...

2012
Jingming Wu Ruikang Hu Junqi Yue Zhaoguang Yang Lifeng Zhang

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...

Journal: :Rapid communications in mass spectrometry : RCM 2013
Yan An Zeland Schwartz Glen P Jackson

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...

2013
Charles Harrison

..................................................................................................................................................v INTRODUCTION....................................................................................................................................1 1. Gastrointestinal tract (GI)............................................................................

2011
LACRIMIOARA SENILA ADRIANA GOG MARIN SENILA CECILIA ROMAN LUMINITA SILAGHI-DUMITRESCU

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...

2003
TOMASZ ŚNIEGOCKI JAN ŻMUDZKI ANDRZEJ POSYNIAK STANISŁAW SEMENIUK

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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