Premium
Optimization of the ESI and APCI experimental variables for the LC/MS determination of s‐triazines, methylcarbamates, organophosphorous, benzimidazoles, carboxamide and phenylurea compounds in orange samples
Author(s) -
Titato Guilherme M.,
Bicudo Rogério C.,
Lanças Fernando M.
Publication year - 2007
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1310
Subject(s) - chemistry , atmospheric pressure chemical ionization , chromatography , mass spectrometry , electrospray ionization , chemical ionization , analytical chemistry (journal) , pesticide , orange (colour) , electrospray , ionization , detection limit , ion , organic chemistry , food science , agronomy , biology
In this work, ten selected pesticides of different chemical groups, indicated to orange culture, were extracted and determined by liquid chromatography–mass spectrometry using both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) operating in the positive ion detection mode. Applying a variables selection technique verified that cone voltage, source temperature and drying‐gas flow‐rate are the critical variables when the ESI was used, while cone voltage was found to be the only critical variable for the MS system, operating with the APCI ionization mode. After optimization of the most important parameters through the variables selection technique, the selected ion‐recording (SIR) mode, monitoring the [M + H] + species for all the compounds, was applied for the method validation of the pesticides, in both ionization modes. In orange samples, matrix effects did not interfere with the determination of the pesticides. Pesticides quantification limits ranged from 10 to 50 µg kg −1 for ESI and from 8.2 to 45 µg kg −1 for APCI. Linearity was studied from LOQ upto 200 times LOQ values ( r > 0.98). Recoveries obtained were in the range of 70.2–100.5% (RSDs less than 10%). In order to guarantee that the identification and confirmation of the studied pesticides in real samples were unequivocal, characteristic fragment ions of the pesticides were obtained by varying the cone voltage (in‐source CID). Copyright © 2007 John Wiley & Sons, Ltd.