Determination of polar organophosphorus pesticides in aqueous samples by direct injection using liquid chromatography–tandem mass spectrometry

Determination of 13 Organic Toxicants in Human Blood by Liquid-Liquid Extraction Coupling High-Performance Liquid Chromatography Tandem Mass Spectrometry

“…As a result, it was found that methanol/water on the optimized gradient mode resulted in intense peaks for DMT, OMT, DDVP, CBF, FEN DZP, EST, ALP, TAL, CLP and PNG in PI mode while ionization efficiency in NI mode for BBT and PNB was better with acetonitrile than methanol because acetonitrile was a weaker proton donor than methanol. 43 Signal enhancement can be achieved through the utilization of buffer additives in the mobile phase, such as ammonium formate, acetic acid, and formic acid. 44,45 In the current method, formic acid was selected as modifier because it gave the overall best results for DMT, OMT, DDVP, CBF, FEN DZP, EST, ALP, TAL, CLP and PNG in respect to sensitivity.…”

Determination of trichlorfon residues in vegetables using a quantum dot-labeled biomimetic immunoassay method followed by capillary electrophoresis

“…There have been some reports regarding the detection methods for organophosphorus pesticide residues, such as gas chromatography (GC) coupled with tandem mass spectrometry (Chen, Chen, Feng, & Li, 2009;Pang et al, 2006), GC with flame photometric detection (Dugo, Bella, Torre, & Saitta, 2005;Liu et al, 2014), GC with nitrogen-phosphorus detection (Shen, Su, Zhu, & Gao, 2007;Tian, Liu, Fang, An, & Duan, 2014), high performance liquid chromatography (He & Lee, 2006;Seebunrueng, Santaladchaiyakit, & Srijaranai, 2014), liquid chromatography coupled with tandem mass spectrometry (Ingelse, van Dam, Vreeken, Mol, & Steijger, 2001;Li et al, 2013;Mol, van Dam, & Steijger, 2003) , chemiluminescence (Chen, Lin, Cai, Chen, & Wang, 2008;Li, He, & Xu, 2007;Li, Hu, Huo, & Xu, 2006;Wang, Zhang, Wang, Yang, & Zhang, 2001), capillary electrophoresis-quantum dot/laser induced detection (CE-QD/LIF) (Chen & Fung, 2010) and biosensor (Sun & Wang, 2010). However, these methods require expensive instruments and lengthy analytical times.…”

Selective Solid-Phase Extraction Using Molecularly Imprinted Polymer for Analysis of Methamidophos in Water and Soil Samples

“…5) In the European Union, maximum allowable concentration of 0.1 mg/L for each individual organophosphate pesticide in drinking water is in force. 6) Hence it is necessary to establish a more selective and sensitive methodology for the determination of methamidophos in environmental samples.…”

“…Methamidophos is extremely water-soluble, and in contrast to most other pesticides discussed in the literature, is highly polar, e.g., oxamyl, acidic pesticides, 7) dichlorvos, mevinphos, dimethoate, 8) and not extractable (after the adequate pH adjustment) using the more common liquid-liquid extraction. 6) Solid-phase extraction is a routine sample preparation technique for extracting analytes from a complex matrix. Solid-phase extraction is easy to perform, can cope with large loads, gives higher recoveries, consumes relatively small amounts of organic solvents, and can be automated, and a wide range of stationary phases are available.…”

“…Solid-phase extraction is easy to perform, can cope with large loads, gives higher recoveries, consumes relatively small amounts of organic solvents, and can be automated, and a wide range of stationary phases are available. 9,10) Solid-phase extraction has been used to perform polar organophosphates enrichment, 6,11,12) but the non-selective sorbents (such as C 18 silica, ENVI and Oasis HLB) used in solid-phase extraction often result in defects, such as low specificity and low selectivity. 6,12) Solid-phase extraction involving molecularly imprinted polymers (MIPs), a technique commonly referred to as molecularly imprinted solid-phase extraction (MISPE), is a popular tool capable of overcoming these disadvantages.…”