Simultaneous enantioselective determination of isocarbophos and its main metabolite isocarbophos oxon in rice, soil, and water by chiral liquid chromatography and tandem mass spectrometry

Abstract

An efficient enantioselective method for the simultaneous determination of isocarbophos and its main metabolite isocarbophos oxon in rice, soil, and water was developed using liquid chromatography with tandem mass spectrometry. The enantioseparation was performed on a Chiralpak AD-3R column at 30°C using gradient elution. Target compounds were extracted from soil and rice using acetonitrile with omission of a clean-up procedure, while a C18 solid-phase extraction column was used for water samples. Quantification was achieved using matrix-matched calibration. The overall mean recoveries for isocarbophos and isocarbophos oxon enantiomers from the five matrices were 89.7-103 and 90.1-98.7%, with relative standard deviations of 2.1-5.4 and 2.5-4.7%, respectively. Moreover, the absolute configurations of isocarbophos oxon enantiomers were determined by liquid chromatography with tandem mass spectrometry through incubation of each isocarbophos enantiomer in soil, the first eluting enantiomer being confirmed as (R)-(-)-isocarbophos oxon. The proposed method was applied to real soil samples and satisfactory results were obtained.

Dissipation behavior of phorate and its toxic metabolites in the sandy clay loam soil of a tropical sugarcane ecosystem using a single-step sample preparation method and GC-MS

“…Yao et al. also could obtain acceptable range of recoveries of isocarbophos and its metabolite isocarbophos oxon from hydrated soil samples by using acidified acetonitrile for extraction followed by direct quantification without further cleanup with d‐SPE sorbents. Feng et al.…”

“…Lan et al [17] determined the residues of saflufenacil and its metabolites in soil matrix by employing a modified QuEChERS method, in which the d-SPE cleanup was omitted. Yao et al [18] also could obtain acceptable range of recoveries of isocarbophos and its metabolite isocarbophos oxon from hydrated soil samples by using acidified acetonitrile for extraction followed by direct quantification without further cleanup with d-SPE sorbents. Feng et al [19] employed a modified QuEChERS method involving extraction in citrate-buffered acetonitrile and d-SPE cleanup with PSA (100 mg/g of matrix) to determine the residues of 36 pesticides including phorate in soil with the recoveries ranged between 63 and 126%.…”

“…Correia-Sa´et al [20] employed a modified QuEChERS method for determination of 14 organochlorine pesticides in soils with varying levels of organic carbon. They could get good recoveries (77-130%) when the soil samples (5 g) were initially hydrated with 3 mL of deionized water before proceeding for extraction in citratebuffered acetonitrile (7 mL) and d-SPE cleanup with PSA and C 18 . It was also reported that 20 mL of acetonitrile was required to extract the residues from 5 g of soil matrix as 10 mL was inadequate to get supernatant for d-SPE cleanup.…”

Fullerol Nanocatalysis and Trimodal Surface Plasmon Resonance for the Determination of Isocarbophos

“…Therefore, a rapid and accurate analytical method for the estimation of IPS is required. The main methods for IPS detection include chromatography (Huang et al, 2002 ; Yao et al, 2015 ; Li et al, 2017 ), chemiluminescence (Chen et al, 2012 ), and electrochemical methods (Yan et al, 2012 ). In recent years, new methods, such as highly selective aptamers and catalytic techniques, have been used to detect IPS (Pang et al, 2014 ; Zhang et al, 2014 ; Chen et al, 2017 ).…”

Simultaneous enantioselective determination of six pesticides in aqueous environmental samples by chiral liquid chromatography with tandem mass spectrometry

“…Due to huge consumption, many pesticides that possess one or more chiral centers are frequently found in water resources, such as surface water, groundwater, sea water, and many other aquifers . In the past, most of the enantioseparations of chiral pesticides were carried out under normal mode by LC–UV .…”