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Analysis of pesticides in soy milk combining solid‐phase extraction and capillary electrophoresis‐mass spectrometry
Author(s) -
HernándezBorges Javier,
RodríguezDelgado Miguel Ángel,
GarcíaMontelongo Francisco J.,
Cifuentes Alejandro
Publication year - 2005
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200500014
Subject(s) - chromatography , chemistry , capillary electrophoresis , solid phase extraction , mass spectrometry , capillary electrophoresis–mass spectrometry , pesticide , extraction (chemistry) , electrospray ionization , agronomy , biology
In this work, the determination of a group of triazolopyrimidine sulfoanilide herbicides (cloransulam‐methyl, metosulam, flumetsulam, florasulam, and diclosulam) in soy milk by capillary electrophoresis‐mass spectrometry (CE‐MS) is presented. The main electrospray interface (ESI) parameters (nebulizer pressure, dry gas flow rate, dry gas temperature, and composition of the sheath liquid) are optimized using a central composite design. To increase the sensitivity of the CE‐MS method, an off‐line sample preconcentration procedure based on solid‐phase extraction (SPE) is combined with an on‐line stacking procedure (i. e. normal stacking mode, NSM). Samples could be injected for up to 100 s, providing limits of detection (LODs) down to 74 μg/L, i. e., at the low ppb level, with relative standard deviation values (RSD,%) between 3.8% and 6.4% for peak areas on the same day, and between 6.5% and 8.1% on three different days. The usefulness of the optimized SPE‐NSM‐CE‐MS procedure is demonstrated through the sensitive quantification of the selected pesticides in soy milk samples.