Simultaneous determination of thiamethoxam, clothianidin, and metazachlor residues in soil by ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Abstract

A rapid pioneering method has been developed to simultaneously determine residues of three pesticides (thiamethoxam, clothianidin, and metazachlor) in soil by ultrahigh performance liquid chromatography coupled to a mass spectrometry detector (quadrupole time-of-flight). An efficient extraction procedure (90-105% average analyte recoveries) has also been proposed, involving solid-liquid extraction by a mixture of water and methanol (60:40, v/v), centrifugation, and concentration. A chromatographic analysis of the compounds was achieved in 5.5 min by means of a core-shell technology based column (Kinetex EVO C , 50 × 2.1 mm, 1.7 μm, 100 Å). The mobile phase (0.3 mL/min, gradient elution mode) consisted of 0.1% v/v formic acid in water and 0.1% v/v formic acid in acetonitrile. The method was fully validated in terms of selectivity, detection and quantification limits, matrix effect, linearity, trueness, and precision. Low limits of detection and quantification were obtained, ranging from 0.2 to 3.0 μg/kg, which are similar to those published in previous studies, while the absence of a significant matrix effect allowed quantification of the pesticides with standard calibration curves. The proposed method was applied for an analysis of pesticides in several soil samples from experimental fields dedicated to oilseed rape cultivars.

Simultaneous determination of residues of thiamethoxam and its metabolite clothianidin in tobacco leaf and soil using liquid chromatography‐tandem mass spectrometry

“…Matrix enhancement was observed for thiamethoxam and clothianidin in soil with both ME values >0 (311 and 236%, Table ). These data was similar to the results of previous studies (Valverde, Ares, Bernal, Nozal, & Bernal, ). Matrix suppression was observed for thiamethoxam and clothianidin in fresh tobacco leaf and cured tobacco leaf with negative ME values (−53, −60, −29 and − 35%, Table ), which was consistent with the matrix effects of two analytes on Swiss chard (Rahman et al, ).…”

Dynamics and dietary risk assessment of thiamethoxam in wheat, lettuce and tomato using field experiments and computational simulation

“…Its main metabolite is clothianidin (CAS: 210880-92-5) (Table S1) with a maximum occurrence fraction in soil of 35.6%. Liquid chromatography (LC) (Abd-Alrahman, 2014;Jyot and Singh, 2017;Ramasubramanian et al, 2012;Zhou et al, 2006) and LC-MS (Rahman et al, 2015;Valverde et al, 2016) have been widely used to determine residue and dissipation of thiamethoxam (Gupta et al, 2008;Karmakar and Kulshrestha, 2009;Li et al, 2007;Liu et al, 2009;Pareja et al, 2012;Singh and Kulshrestha, 2005). Efforts have also focused on understanding the degradation of thiamethoxam as well as its metabolites (Fan and Shi, 2017;Hilton et al, 2016;Yang et al, 2014).…”

Simultaneous determination of the metabolites of the herbicide metazachlor in agricultural crops by LC–MS/MS

“…Metazachlor [2-chloro-N-(pyrazol-1-ylmethyl)acet-2′,6′xylidide] (Fig. 1), a chloroacetamide herbicide developed by BASF, was produced by introducing 2,6-dimethylaniline (2,6-DMA; C 8 H 11 N) into the structure of chloroacetamide (C 2 H 4 ClNO) [1][2][3]. Metazachlor is mainly used to control annual weeds and broadleaf weeds before or after germination, and is absorbed through the roots or stems.…”

“…Metazachlor is mainly used to control annual weeds and broadleaf weeds before or after germination, and is absorbed through the roots or stems. Absorbed metazachlor affects elongase activity during lipid biosynthesis, thereby inhibiting the synthesis of very-long-chain fatty acids, as well as interfering with cell division and tissue differentiation during growth, resulting in the production of deformed seeds [1][2][3][4][5][6]. Metazachlor was completely metabolized in the plant and was not detected at harvest [7].…”