Multiresidue Pesticides Analysis of Vegetables in Vietnam by Ultrahigh-Performance Liquid Chromatography in Combination with High-Resolution Mass Spectrometry (UPLC-Orbitrap MS)

Abstract

An ultrahigh-performance liquid chromatography in combination with high-resolution mass spectrometry Thermo Q-Extractive Focus Orbitrap MS has been introduced for analysis of multiclass pesticides in vegetable samples collected in Hanoi, Vietnam. Multiclass pesticides were separated on the Thermo Hypersil Gold PFP column utilizing a gradient of the mobile phase consisting of 5 mM ammonium formate, 0.1% formic acid in deionized water, and methanol. The target analytes were detected in the full-scan mode on Thermo Scientific Q-Exactive Focus Orbitrap MS for quantitation at the optimum operating conditions. These conditions included, but not limit to, the resolution of 70000 at the full width at half maximum in both positive and negative mode, mass range from 80 to 1000 m/z, and optimized parameters for the heated electrospray ionization source. The identification of the analytes in real samples was based on retention times, mass to charge ratios, mass accuracies, and MS/MS spectra at the confirmation mode with the inclusion list of target analytes. The mass accuracies of target analytes were from −4.14 ppm (dinotefuran) to 1.42 ppm (cinosulfuron) in the neat solvent and from −3.91 ppm (spinosad D) to 1.29 ppm (cinosulfuron) in the matrix-matched solution. Target analytes in the vegetable-based matrix were extracted by the QuEChERS method. Some critical parameters of the analytical method such as linearity, repeatability, limit of detection, and limit of quantitation have been evaluated and implemented. Excellent LOD and LOQ of the developed method were achieved at the range of 0.04–0.85 and 0.13–2.9 μg·kg−1, respectively. Intraday and interday repeatability of the analytical signal (peak area, n=6) of the developed method were below 3% and 10%, correspondingly. The matrix effect, extraction recovery, and overall recovery were fully investigated by spiking experiments. Experimental results demonstrated that the ionization suppression or enhancement was the main contribution on the overall recoveries of target analytes. Finally, the in-house validated method was applied to pesticides screening in vegetables samples in local villages in Hanoi, Vietnam. The concentrations of all target analytes were below limit of quantitation and lower than US-FDA or EU maximum residue levels.

Determination of Pharmaceutical Residues by UPLC-MS/MS Method: Validation and Application on Surface Water and Hospital Wastewater

“…These samples were then subjected for UPLC-MS/MS measurement. The peak area of target analyte was used to calculate the matrix effect, extraction recovery, and overall recovery as instructed by Vu-Duc et al [ 27 ]. The experimental results of matrix effect, extraction recovery, and overall recovery of all target compounds in both matrices are presented in Table 3 .…”

“…Particularly, ME was compared using the signals of analytes in samples spiked after extraction (in sample matrix solution) and analytes in the “neat” solvent. The matrix effect, extraction efficiency, and overall recovery were calculated as Vu-Duc et al proposed [ 27 ]. Briefly, the ME, ionization enhancement, or suppression in mass spectrometry was assessed via postextraction spiking experiments.…”

Quality Control of Pesticide Residue Measurements and Evaluation of Their Results

“…To control the safe and efficient use of pesticides, their residues are regularly monitored in food and environmental samples in many countries according to risk-based sampling plans [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] or targeted surveillance with limited scope and sampling targets. For example, the world-wide activities are demonstrated with some selected publications from Argentina to Vietnam [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. In the European Union the largest number of residues tested within the EU-coordinated and national pesticide residue monitoring programs were reported in 2020 by Luxembourg (659), Malta (643), Germany (626), France (619) and Belgium (617) [ 47 ].…”

Foodinformatic prediction of the retention time of pesticide residues detected in fruits and vegetables using UHPLC/ESI Q-Orbitrap

“…The gas and liquid chromatography (GC and LC) mass spectrometry (MS) techniques are widely applied for the determination of pesticide residues in food products (Poma et al, 2019), particularly by applying the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method (Anastassiades et al, 2003;Lehotay et al, 2010). On the other hand, in recent years several authors have demonstrated the importance of the ultrahigh-performance liquid chromatography and electrospray ionization quadrupole Orbitrap high-resolution (UHPLC/ESI Q-Orbitrap) mass spectrometry (MS) for the determination of pesticide residues in diverse samples of raw food products (Vu-Duc et al, 2019;Wang et al, 2019) and processed foods (Jia et al, 2014). All of these methods generate analytical responses called retention times (t R ) or retention indices (I).…”

“…This parameter considers the maximum (apex) of the peak belonging to a particular pesticide. The t R for a given compound is not fixed, since many factors affect its determination; for instance, the mobile phase flow rate, temperature differences in the oven and the column, as well as column length and column degradation (Vu-Duc et al, 2019).…”