Analysis of Hydrazine in Drinking Water by Isotope Dilution Gas Chromatography/Tandem Mass Spectrometry with Derivatization and Liquid−Liquid Extraction

2008 ◽  
Vol 80 (14) ◽  
pp. 5449-5453 ◽  
Author(s):  
William E. Davis, II ◽  
Yongtao Li
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Drinking Water ◽  
Tandem Mass Spectrometry ◽  
Isotope Dilution ◽  
Liquid Extraction ◽  
Tandem Mass ◽  
Liquid Liquid Extraction ◽  
Chromatography Tandem Mass Spectrometry

scholarly journals Development and validation of quantitative analytical method for 50 drugs of antidepressants, benzodiazepines and opioids in oral fluid samples by liquid chromatography–tandem mass spectrometry

2020 ◽  
Author(s):  
Ana Carolina Furiozo Arantes ◽  
Kelly Francisco da Cunha ◽  
Marilia Santoro Cardoso ◽  
Karina Diniz Oliveira ◽  
Jose Luiz Costa
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Oral Fluid ◽  
Liquid Extraction ◽  
Simple Liquid ◽  
Tandem Mass ◽  
Liquid Liquid Extraction ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract Purpose We developed and validated a method for quantitative analysis of 50 psychoactive substances and metabolites (antidepressants, benzodiazepines and opioids) in oral fluid samples using simple liquid–liquid extraction procedure followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Method Oral fluid samples were collected using Quantisal™ device and extracted by liquid–liquid extraction with 1.0 mL of methyl tert-butyl ether and then analyzed using LC–MS/MS. Results The method attended method validation criteria, with limits of quantification as low as 0.5 and 1.0 ng/mL, and linearity between 0.5–50.0 ng/mL for antidepressants, 0.5–25.0 ng/mL for benzodiazepines and 1.0–50.0 ng/mL to opioids. During method validation, bias and imprecision values were not greater than 16 and 20%, respectively. Ionization suppression/enhancement bias results were not greater than 25%. No evidence of carryover was observed. Sample stability studies showed that almost all analytes were stable at 25 °C for 3 days and at 4 °C for 7 days. Freeze–thaw cycles stability showed that most antidepressants and opioids were stable under these conditions. Autosampler stability study showed that all analytes were stable for 24 h, except for nitrazepam and 7-aminoclonazepam. Thirty-eight authentic oral fluid samples were analyzed; 36.8% of the samples were positive for 2 drugs. Citalopram was the most common drug found, followed by venlafaxine. Conclusions The method was validated according to international recommendations for the 50 analytes, showing low limits of quantification, good imprecision and bias values, using simple liquid–liquid extraction, and was successfully applied to authentic oral fluid samples analysis.

scholarly journals Determination of Eight Coccidiostats in Eggs by Liquid–Liquid Extraction–Solid-Phase Extraction and Liquid Chromatography–Tandem Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 987 ◽  
Author(s):  
Bo Wang ◽  
Jianyu Liu ◽  
Xia Zhao ◽  
Kaizhou Xie ◽  
Zhixiang Diao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Tandem Mass ◽  
Liquid Liquid Extraction ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

A method for the simultaneous determination of robenidine, halofuginone, lasalocid, monensin, nigericin, salinomycin, narasin, and maduramicin residues in eggs by liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed. The sample preparation method used a combination of liquid–liquid extraction (LLE) and solid-phase extraction (SPE) technology to extract and purify these target compounds from eggs. The target compounds were separated by gradient elution using high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography (UPLC). Tandem mass spectrometry was used to quantitatively and qualitatively analyze the target compounds via electrospray ionization (ESI+) and multiple reaction monitoring mode. The HPLC–MS/MS and UPLC–MS/MS methods were validated according to the requirements defined by the European Union and the Food and Drug Administration. The limits of detection and limits of quantification of the eight coccidiostats in eggs were 0.23–0.52 µg/kg and 0.82–1.73 µg/kg for HPLC–MS/MS, and 0.16-0.42 µg/kg and 0.81-1.25 µg/kg for UPLC–MS/MS, respectively. The eggs were spiked with four concentrations of the eight coccidiostats, and the HPLC–MS/MS and UPLC–MS/MS average recoveries were all higher than 71.69% and 72.26%, respectively. Compared with the HPLC–MS/MS method, utilizing UPLC–MS/MS had the advantages of low reagent consumption, a short detection time, and high recovery and precision. Finally, the HPLC–MS/MS and UPLC–MS/MS methods were successfully applied to detect eight coccidiostats in 40 eggs.

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