Gas chromatography/mass spectrometry and gas chromatography/mass spectrometry/mass spectrometry of methyl ester/methoxime/trimethylsilyl ether derivatives of thromboxanes

1988 ◽  
Vol 15 (3) ◽  
pp. 139-142 ◽  
Author(s):  
Horst Schweer ◽  
Hannsjörg W. Seyberth ◽  
Claus O. Meese ◽  
Otto Fürst
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Methyl Ester ◽  
Trimethylsilyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Derivatives Of ◽  
Mass Spectrometry Mass Spectrometry

Liquid Chromatographic Determination of Monensin in Chicken Tissues with Fluorometric Detection and Confirmation by Gas Chromatography-Mass Spectrometry

1986 ◽  
Vol 69 (3) ◽  
pp. 443-448
Author(s):  
Keigo Takatsuki ◽  
Shigeru Suzuki ◽  
Isamu Ushizawa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Trimethylsilyl Ether ◽  
Phosphate Buffer Solution ◽  
Fluorescent Labeling ◽  
Gas Chromatography Mass Spectrometry ◽  
Fluorometric Detection ◽  
Chicken Tissues ◽  
Chromatography Mass Spectrometry

Abstract An accurate, sensitive method is described for the determination of monensin residue in chicken tissues by liquid chromatography (LC), in which monensin is derivatized with a fluorescent labeling reagent, 9-anthryldiazomethane (ADAM), to enable fluorometric detection. Samples are extracted with methanol-water (8 + 2), the extract is partitioned between CHCl3 and water, and the CHC13 layer is cleaned up by silica gel column chromatography. Free monensin, obtained by treatment with phosphate buffer solution (pH 3) at 0°C, is derivatized with ADAM and passed through a disposable silica cartridge. Monensin-ADAM is identified and quantitated by normal phase LC using fluorometric detection. The detection limit is 1 ppb in chicken tissues. Recoveries were 77.6 ± 1.8% at 1 ppm, 56.7 ± 7.1% at 100 ppb, and 46.5 ± 3.7% at 10 ppb fortification levels in chicken. Gas chromatography-mass spectrometry is capable of confirming monensin methyl ester tris trimethylsilyl ether in samples containing residues >5 ppm.

Estradiol-17 beta determined in plasma by gas chromatography-mass spectrometry with selected ion monitoring of mixed silyl ether-perfluoroacyl ester derivatives and use of various stable-isotope-labeled internal standards.

1989 ◽  
Vol 35 (4) ◽  
pp. 532-536 ◽  
Author(s):  
L Dehennin
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Stable Isotope ◽  
Trimethylsilyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Specific Method ◽  
Silyl Ether ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Target Values

Abstract A highly specific method is described for measuring estradiol-17 beta (E2) in plasma by gas chromatography-mass spectrometry (GC-MS) associated with stable isotope dilution. A mixed derivative, E2-3-trimethylsilyl ether-17-heptafluorobutyrate (E2-3-TMS-17-HFB), was found to have excellent analytical properties. The specificity of the derivatization procedure exploits a unique feature of estrogens: the selective exchange of a phenolic perfluoroacyl ester for a trialkylsilyl ether. No significant differences in E2 concentration could be ascribed to the use of 2H- or 13C-labeled analogs, thus ruling out interferences from possible isotope exchange commonly attributed to deuterated compounds. Precision is closely similar to that for methods in which the more common E2-3, 17-bis(trimethylsilyl) ether and E2-3, 17-bis(heptafluorobutyrate) derivatives are used. Sensitivity and specificity of the mixed 3-TMS-17-HFB derivative allow adequate determinations of E2, even in plasma from males, in 2-mL samples. Interlaboratory mean concentrations of E2 obtained by routine immunoassays were consistently higher than the target values estimated by GC-MS, particularly at concentrations less than 100 pmol/L.

Comprehensive analysis of metabolites in Corynebacterium glutamicum by gas chromatography/mass spectrometry

2004 ◽  
Vol 385 (9) ◽  
pp. 853-861 ◽  
Author(s):  
Sergey Strelkov ◽  
Mirko von Elstermann ◽  
Dietmar Schomburg
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Corynebacterium Glutamicum ◽  
Growth Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Fast Method ◽  
Chromatography Mass Spectrometry ◽  
High Matrix ◽  
First Time ◽  
Derivatives Of

AbstractAn analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation ofCorynebacterium glutamicum. For the first time a fast method for metabolic screening that can be automated is described for this organism. More than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. Out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quantified in one sample. In spite of the different chemical nature of metabolites and high matrix content, a measurement reproducibility in the range of 6% error was achieved. The application of this method for the analysis of the adaptation ofC. glutamicumto different growth conditions is demonstrated.

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