Multiresidue analysis of pesticides with hydrolyzable functionality in cooked vegetables by liquid chromatography tandem mass spectrometry

Abstract

It would be preferable for pesticide residues substituted by hydrolyzable functionality to be analyzed after cooking because their structures are apt to degrade during boiling and/or heating. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative determination of 44 pesticide residues with hydrolyzable functional group in five typical vegetable widely consumed in Republic of Korea is described. The sample clean-up was carried out according to the method of Food Code No. 83 established by the Korea Food and Drug Administration (KFDA). Zorbox XDB-C(18) column was selected for the analysis because of the best peak separation. The LC mobile phase consisted of water and 5 mm methanolic ammonium formate, which resulted in a peak shape with good symmetry at each run. Tandem mass spectroscopic (MS/MS) experiments were performed in ESI positive mode and the multiple reaction monitoring modes. A conventional matrix effect was modified to more comprehensive form 100gamma(ij) (%). A high matrix effect (<-30%) was detected for the seven polar pesticides, namely thiamethoxam, clothianidin, acetamiprid, aldicarb, thiacloprid, pirimicarb and methabenzthiazuron. The limits of detection were in the range of 0.1-8.1 microg/kg, indicating a good sensitivity. Most of the recoveries ranged from 70 to 131% with RSDs <or= 20%. The current method allowed rapid quantitation and identification of low pesticide levels in the cooked vegetable samples. Of the screened pesticide residues, only fluquinconazole and dimethomorph below the maximum residue levels established by the KFDA were detected in onion and cucumber samples.

Pesticides and Their Degradation Products Including Metabolites: Chromatography-Mass Spectrometry Methods

“…LC-ESI + -MS/MS is more frequently chosen than GC-MS methods for the analysis of carbamates and phenylureas in chemical class-specific or multiclass methods [39,[48][49][50][51][52][53][54][55][56][57][58]. OPs, carbamates, and phenylureas have a wide range of polarities so they can elute over similar time periods when typical reversed-phase stationary phases are used; however, in general, phenylureas elute later than carbamates and within the time range for OPs and pyrethroid insecticides.…”

UHPLC-DAD method for the determination of neonicotinoid insecticides in single bees and its relevance in honeybee colony loss investigations

“…In these methods, but also in methods for the analysis of simpler matrices of interest (i.e., honey [36,37], fruits [38][39][40][41][42], or vegetables [41][42][43][44][45][46][47]), great effort has been devoted to both extraction and cleanup procedures that precede instrumental analysis [48]. To obtain satisfactory recovery factors for both neonicotinoids and their main metabolites, several versions of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method originally proposed by Anastassiades et al [49] were developed [33,35,37,40,46].…”

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

“…In recent years, various analytical methods have been reported for the determination of thiamethoxam or clothianidin in agro‐products and environmental samples, including high‐performance liquid chromatography (HPLC; Vichapong, Burakham, & Srijaranai, , ; Farouk, Hussein, & El‐Azab, ), liquid chromatography with mass spectrometry (LC–MS; Yáñez, Bernal, Nozal, Martín, & Bernal, ), liquid chromatography–tandem mass spectrometry (LC–MS/MS; Lee et al, ; Campillo, Viñas, Férez‐Melgarejo, & Hernández‐Córdoba, ; Yamamuro, Ohta, Aoyama, & Watanabe, ; Zheng et al, ; Hao, Noestheden, Zhao, & Morse, ) and ultra‐performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS; Xiao, Yang, Li, Fan, & Ding, ; Zhang et al, ; David, Botías, Abdul‐Sada, Goulson, & Hill, ; Sadaria, Supowit, & Halden, ). For instance, Farouk et al () developed an HPLC method to determine thiamethoxam and clothianidin in cucumbers and soil with a quick, easy, cheap, effective, rugged and safe (QuEChERS) pretreatment procedure, with average recoveries between 99.07% and 101.45%.…”