Rapid and Simultaneous Analysis of 360 Pesticides in Brown Rice, Spinach, Orange, and Potato Using Microbore GC-MS/MS

Abstract

A multiresidue method for the simultaneous and rapid analysis of 360 pesticides in representative agricultural produce (brown rice, orange, spinach, and potato) was developed using a modified QuEChERS procedure combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). Selected reaction monitoring transition parameters (e.g., collision energy, precursor and product ions) in MS/MS were optimized to achieve the best selectivity and sensitivity for a wide range of GC-amenable pesticides. A short (20 m) microbore (0.18 mm i.d.) column resulted in better signal-to-noise ratio with reduced analysis time than a conventional narrowbore column (30 m × 0.25 mm i.d.). The priming injection dramatically increased peak areas by masking effect on a new GC liner. The limit of quantitation was <0.01 mg/kg, and the correlation coefficients (r) of matrix-matched standards were >0.99 within the range of 0.0025-0.1 mg/kg. Acetonitrile with 0.1% formic acid without additional buffer salts was used for pesticide extraction, whereas only primary-secondary amine (PSA) was used for dispersive solid phase extraction (dSPE) cleanup, to achieve good recoveries for most of the target analytes. The recoveries ranged from 70 to 120% with relative standard deviations of ≤20% at 0.01 and 0.05 mg/kg spiking levels (n = 6) in all samples, indicating acceptable accuracy and precision of the method. Seventeen real samples from local markets were analyzed by using the optimized method, and 14 pesticides in 11 incurred samples were found at below the maximum residue limits.

Residue Analysis of Insecticides in Potatoes by QuEChERS-dSPE/UHPLC-PDA

“…Moreover, the analytical method developed was linked with other gas (GC) and liquid chromatography (LC) methods reported in the literature for pesticide quantification in vegetables, Table 4 [1,3,5,8,12,16,[31][32][33][34][35]. The sample amount (g), LOD, LOQ and recovery (analytical performance) were considered to demonstrate the advantages of the QuEChERS-dSPE/UHPLC-PDA method here validated.…”

“…Therefore, it is crucial to regulate such contaminants in food, and to determine if they pose any danger to public health and to the environment. In this scenario, to guarantee that levels of insecticide residues on vegetables are safe, they must meet current tolerances or maximum residue limits (MRLs, Table 1), normally in µg/kg, which are strictly set by the European Union (EU), Codex Alimentarius (CA) and other organizations [6,8].…”

“…The analysis of insecticide residues in foods requires highly selective and sensitive analytical methods. Current analytical methods include mass spectrometry (MS) or tandem mass spectrometry (MS/MS) detection, coupled to gas (GC) or liquid chromatography (LC) [4,8,16]. Nevertheless, ultra-high-performance chromatography (UHPLC) can be a fascinating substitute in the analysis of insecticide residues, due to its great resolution, reduced analysis time, lower solvent volumes and improved selectivity [17].…”

Unpacking the Pathogen Box—An Open Source Tool for Fighting Neglected Tropical Disease

“…Trifloxystrobin is a broad‐spectrum antifungal, whose EE isomer is responsible for biological activity . The 1,2,4‐triazoles 1 and 2 are both known antifungal pesticides, which, like the more popular 1,2,4‐triazole antifungals fluconazole ( 4 ) and posaconazole ( 5 , MMV688774), inhibit CYP51 in the sterol biosynthesis pathway. CYP51 has been validated as a target in T. brucei , with 5 displaying the capacity to inhibit the Tb variant of this enzyme, while X‐ray co‐crystal studies of CYP51 from T. cruzi and T. brucei with compounds 4 (PDB IDs: https://www.rcsb.org/structure/2WX2 and https://www.rcsb.org/structure/2WUZ) and 5 (PDB ID: https://www.rcsb.org/structure/3K1O) indicate that the respective active sites are nearly identical .…”

A simultaneous multiresidue analysis for 203 pesticides in soybean using florisil solid-phase extraction and gas chromatography–tandem mass spectrometry

“…3) indicated that the signals of most analytes were enhanced by co-eluent matrices throughout the t R . Many previous studies have reported signal enhancement by crop matrices in GC-MS or GC-MS/MS [22][23][24]. The average matrix effect for target pesticides was 5.5%.…”