Comparison of four mass analyzers for determining carbosulfan and its metabolites in citrus by liquid chromatography/mass spectrometry

Abstract

Four liquid chromatography/mass spectrometry (LC/MS) systems, equipped with single quadrupole, triple quadrupole (QqQ), quadrupole ion trap (QIT) and quadrupole time-of-flight (QqTOF) mass analyzers, were evaluated for the analysis of carbosulfan and its main transformation products. The comparison of quantitative aspects (sensitivity, precision and accuracy) was emphasized. Results showed that the triple quadrupole instrument reaches at least 20-fold higher sensitivity (LOD from 0.04 to 0.4 microg kg(-1)) compared to the single quadrupole (4-70 microg kg(-1)), the QIT (4-25 microg kg(-1)) and the QqTOF (4-23 microg kg(-1)) instruments. Recoveries were over 70% for all the analytes, except dibutylamine and 7-phenolcarbofuran. Repeatabilities (within-day) were slightly better by the single quadrupole (5-10%) and the QqQ (5-9%) than by the QIT (12-16%) and the QqTOF (9-16%). Both the QqTOF and QIT offer a linear dynamic range of two orders of magnitude whereas the single quadrupole and QqQ of, at least, three orders of magnitude. The method was applied to analyze carbosulfan field-treated orange samples, in which carbosulfan, carbofuran, 3-hydroxycarbofuran, and dibutylamine were found. As an example, the mean carbosulfan concentration was 20 +/- 0.6 microg kg(-1) measured by the QqQ, 22 +/- 1.2 microg kg(-1) by the single quadrupole, 25 +/- 2.8 microg kg(-1) by the QIT, and 20 +/- 1.8 microg kg(-1) by the QqTOF. Although the QqQ is more sensitive and precise, the mean values obtained by the four instruments are acceptable and comparable. The potential of each technique for the verification of the identity of residues detected in oranges is discussed using the concept of identification points.

Phenolic Molecules in Virgin Olive Oils: a Survey of Their Sensory Properties, Health Effects, Antioxidant Activity and Analytical Methods. An Overview of the Last Decade Alessandra

“…In the most cases, single-stage MS is used in combination with UV detection to facilitate the identification of phenolic compounds in olive oil samples with the help of standards and/or reference data. Ion Trap or QqQ provide the possibility of doing MS/MS or MS n , which can be used for structure elucidation or for additional selectivity to gain sensitivity by reducing the chemical noise [157]. MS/MS and MS n involve two (or more) stages of mass analysis, separated by a fragmentation step.…”

Current mass spectrometry strategies for the analysis of pesticides and their metabolites in food and water matrices

“…Developments of multi-residue LC-QqQ-MS methods for various pesticides belonging to different chemical classes have been reported (Soler et al, 2006b;Ferrer, Thurman, & Zweigenbaum, 2007;Pirard et al, 2007;Venkateswarlu et al, 2007;Pan, Xia, & Liang, 2008;Radišic' et al, 2009). New generation QqQ instruments with shorter dwell times (as low as 2 msec) have enabled the acquisition of a much higher number of MRM transitions (around 300) while maintaining high sensitivity.…”

Aspectos analíticos e regulatórios na determinação de resíduos de macrolídeos em alimentos de origem animal por cromatografia líquida associada à espectrometria de massas

“…77,79 Além disso, estes instrumentos são menos robustos para análise de matrizes mais complexas e podem apresentar baixa repetibilidade e faixa dinâmica muito estreita para a quantificação. 80 Instrumentos do tipo QIT têm sido usados para caracterizar os padrões de fragmentação de macrolídeos como a azitromicina. Estes experimentos geraram espectros ricos, esclarecedores da estrutura dos macrolídeos em questão, revelando também impurezas em amostras comerciais destes fármacos desconhecidas até então.…”

“…Estes experimentos geraram espectros ricos, esclarecedores da estrutura dos macrolídeos em questão, revelando também impurezas em amostras comerciais destes fármacos desconhecidas até então. 11,12,56,80,81 …”