Evaluation of a new modified QuEChERS method for the monitoring of carbamate residues in high‐fat cheeses by using UHPLC–MS/MS

A simple and efficient method for the determination of 28 carbamates in high‐fat cheeses is proposed. The methodology is based on a modified quick, easy, cheap, effective, rugged, and safe procedure as sample treatment using a new sorbent (Z‐Sep⁺) followed by ultra‐high performance liquid chromatography with tandem mass spectrometry determination. The method has been validated in different kinds of cheese (Gorgonzola, Roquefort, and Camembert), achieving recoveries of 70–115%, relative standard deviations lower than 13% and limits of quantification lower than 5.4 μg/kg, below the maximum residue levels tolerated for these compounds by the European legislation. The matrix effect was lower than ±30% for all the studied pesticides. The combination of ultra‐high performance liquid chromatography and tandem mass spectrometry with this modified quick, easy, cheap, effective, rugged, and safe procedure using Z‐Sep⁺ allowed a high sample throughput and an efficient cleaning of extracts for the control of these residues in cheeses with a high fat content.     

Determination of synephrine in feeds by a novel quick,easy, cheap,effective, rugged,and safe solid‐phase extraction method combined with UHPLC–MS/MS

To detect and quantify synephrine in feed, an effective analytical method based on quick, easy, cheap, effective, rugged, and safe solid‐phase extraction coupled to ultra high performance liquid chromatography with tandem mass spectrometry was developed with isotopic internal standards. Pretreatment was performed using quick, easy, cheap, effective, rugged, and safe solid‐phase extraction with primary secondary amine and C18 sorbent as sorbents in combination with Oasis MCX column clean‐up to extract and purify feed samples. Tandem mass spectrometry detection in positive ion mode was conducted in positive multiple reaction monitoring mode in addition to the quantitative internal standard method. Two transitions of synephrine at m/z 168.1/150.0 and 168.1/135.0 were selected, and m/z 168.1/135.0 was determined as the quantification ion pair. D₉‐Terbutaline was selected as an internal standard, for which m/z 235.1/153.0 was selected as the quantification ion pair. Good linearity was shown for synephrine in the range of 0.5–50 μg/L, and the correlation coefficient exceeded 0.999. The recoveries in three different feed samples at three spiked levels were 81.42–112.08%, and the relative standard deviations were not greater than 14.66%. The method proposed in this study was reliable and highly effective, and its sensitivity, accuracy, and precision are suitable for determining synephrine residues in feed samples.     

Simultaneous quantification of three tropane alkaloids in goji berries by cleanup of the graphene/hexagonal boron nitride hybrids and ultra‐high‐performance liquid chromatography tandem mass spectrometry

A modified quick, easy, cheap, effective, rugged and safe method was established for simultaneous determination of atropine, anisodamine, and scopolamine in goji berries by using ultra‐high‐performance liquid chromatography with tandem mass spectrometry. The graphene/hexagonal boron nitride hybrids were prepared and first applied as a cleanup adsorbent. Compared to classical cleanup adsorbent (C₁₈), the graphene/hexagonal boron nitride hybrids as adsorbent had better extraction efficiency for the detection of analytes. Under the optimal conditions, the proposed analytical method achieved satisfactory linearity (R² > 0.995), and obtained desirable recoveries ranged from 77.4 to 94.0% with the relative standard deviation of 1.2–6.1% at the concentration levels of 3.2–13.4 µg/kg. The limits of quantitation of atropine, anisodamine, and scopolamine were, respectively, 3.2, 4.6, and 4.5 µg/kg with linearity ranged from 3.2 to 25.4 µg/kg. The modified quick, easy, cheap, effective, rugged, and safe sample preparation with ultra‐high‐performance liquid chromatography and tandem mass spectrometry method was successfully applied to evaluate the safety of goji berries collected from 30 plant areas in China, suggesting its applicability and suitability for the routine analysis of three tropane alkaloids in goji berries.     

Residue determination of plant activator benzo‐1,2,3‐thiadiazole‐7‐ carboxylic acid 2‐benzoyloxyethyl ester in water,soil, and vegetable by gas chromatography with tandem mass spectrometry

This study aimed to develop a rapid, specific and sensitive method for the residue determination of benzo‐1,2,3‐thiadiazole‐7‐carboxylic acid 2‐benzoyloxyethyl ester in soil, vegetable, and water by using gas chromatography with tandem mass spectrometry. During the extraction procedure, modified quick, easy, cheap, effective, rugged, and safe method using acetonitrile was compared with classical oscillating extraction using ethyl acetate and acetone, respectively. Before injection, a solid‐phase extraction cartridge of Bond Elut Florisil was used for sample clean‐up. The method was fully validated and showed satisfactory linearity (r² > 0.99) over the range to be assayed (10–1000 ng/mL), with the limits of detection ranging from 0.092–0.229 ng/mL and the limits of quantification ranging from 0.307–0.763 ng/mL. Recovery values at the spiked concentrations of 10, 100 and 1000 ng/g varied from 85.9–109.3%, 81.0–108.2%, 74.2–113.4% for water, soil and vegetable, respectively, with the maximum relative standard deviations of 12.2%. Results indicated that the established modified quick, easy, cheap, effective, rugged, and safe method coupled to gas chromatography with tandem mass spectrometry was promising for the residue monitoring of benzo‐1,2,3‐thiadiazole‐7‐carboxylic acid 2‐benzoyloxyethyl ester in the environment and vegetable products.     

Determination of pesticides in dried minor tropical fruits from Colombia using the Quick,Easy, Cheap,Effective, Rugged,and Safe method‐gas chromatography–tandem mass spectrometry

The AOAC 2007.1 quick, easy, cheap, effective, rugged, and safe official method, together with gas chromatography coupled to a triple quadrupole mass spectrometer was applied for the analysis of 38 multiclass pesticides from dried fruits typically cultivated and exported from Colombia: uchuva (Physalis peruviana), lulo (Solanum quitoense), guanabana (Anona muricata), and pitahaya (Hylocereus undatus). The whole method was validated in terms of matrix‐matched calibration, matrix effect, and recovery using atrazine‐d₅ as internal standard, triphenylphosphate for quality control of the injection, and a proper mixture of analytes protectants. Matrix‐matched calibration data were found satisfactory for all pesticides and dried fruits, reporting R² values above 0.99. Matrix effect values evidenced the existence of such effect in most cases. The applied procedure gave satisfactory recovery percentages (70–120%) and relative standard deviation values (< 20%) for 92% of the 456 combinations pesticide/fruit studied (spiked levels of 25, 200, and 400 µg/kg). Finally, 20 real dried fruit samples were analyzed and residues of tebuconazole were found in two samples of uchuva at a concentration below the lowest calibration level of the method for one of them and at 10.8 ± 1.6 µg/kg for the other, being below or similar to the general maximum residue level established for monitoring purposes in food applications.     

Multiresidue analysis of 16 pesticides in jujube using gas chromatography and mass spectrometry with multiwalled carbon nanotubes as a sorbent

Although jujube is a minor crop and very few pesticides are registered on it, the application of pesticides during the growth stage of jujube is inevitable to control the pests or diseases. This situation has led to pesticide misuse. A modified quick, easy, cheap, effective, rugged, and safe method using a novel sorbent, multiwalled carbon nanotubes, as a dispersive solid‐phase extraction sorbent combined with gas chromatography with mass spectrometry, was developed for the determination of 16 pesticides in jujube. Under the optimized conditions, recoveries of 76.7–112.4% were obtained for the target analytes at three spiked concentration levels. The relative standard deviations ranged from 1.2 to 12.3%. Limits of detection and limits of quantification for 16 pesticides ranged from 1 to 10 and 3 to 30 μg/kg, respectively. The residues of chlorpyrifos, hexaconazole, tebuconazole, and cyhalothrin were detected from samples obtained from the market.     

Multiresidue method for the determination of 227 pesticides in hot pepper (Capsicum annuum L.) by liquid chromatography with tandem mass spectrometry†

A high‐throughput, rapid, and efficient modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method with a simple cleanup procedure has been developed for simultaneously determining 227 pesticides in pepper samples by liquid chromatography with tandem mass spectrometry (running time: 10 min). Pesticide residues were extracted/partitioned with an acetonitrile/DisQuE QuEChERS pouch, and the resulting samples were cleaned up with different methods: dispersive solid‐phase extraction with primary secondary amines or multiwalled carbon nanotubes and graphitized carbon solid mini cartridge column. The results indicated that multiwalled carbon nanotubes dispersive sorbents achieved the best recoveries and had less matrix interference. The numbers of pesticides with a recovery in the range of 70–120% were 199 at a spiked level of 40 μg/kg. The correlation coefficients (r²) for 227 pesticides were above 0.99, while the limits of quantitation of pesticides in pepper samples ranged from 0.13 to 13.51 μg/kg (S/N = 10), and the limits of detection ranged from 0.04 to 4.05 μg/kg (S/N = 3). The relative standard deviations of approximately 197 pesticides were below 20% at spiked levels of 40 μg/kg. Based on these results, the proposed method was chosen as the most suitable cleanup procedure for the determination of multiresidue pesticides in pepper samples.     

A modified quick,easy, cheap,effective, rugged,and safe method for determination of by-products originating from ozonation of chlorpyrifos and diazinon spiked in cherry tomato and perilla leaf

In this study, sample pretreatment methods have been developed for the determination of chlorpyrifos, diazinon, and their by-products present in cherry tomato and perilla leaf using liquid chromatography-tandem mass spectrometry. To optimize a quick, easy, cheap, effective, rugged, and safe method, the recoveries at each step were evaluated. The steps improved the recoveries of chlorpyrifos, chlorpyrifos oxon, diazinon, diazoxon, and 2-isopropyl-6-methyl-4-pyrimidinol up to 80% or more by removing interferents, but diethyl phosphate was almost lost during the partition procedure, and the 3,5,6-trichloro-2-pyridinol recovery was below 65%. Therefore, the compounds were evaluated using different solvent compositions based on a quick polar pesticides method; note that 100% methanol showed acceptable extraction results. The optimized method provided method detection limits ranging from 0.03 to 1.22 ng/g and good linearities (R² > 0.996). The recovery values were between 82.1 and 113.3%. The intra- and interday reproducibility was evaluated to be within 8.6 and 9.9%, respectively. The method was applied to determine the degradation efficiency of chlorpyrifos and diazinon and their by-products formed during plasma treatment.     

Determination of multi‐pesticide residue in tobacco using multi‐walled carbon nanotubes as a reversed‐dispersive solid‐phase extraction sorbent

A multi‐pesticide residue determination method based on a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method using multiwalled carbon nanotubes as reversed‐dispersive solid‐phase extraction material was validated in 37 representative pesticides in tobacco. Determination was performed using liquid chromatography with tandem mass spectrometry in multiple reaction monitoring mode. Three major types of tobacco leaf samples, namely, flue‐cured, burley, and oriental tobacco were studied and compared. Three factors (extraction time, external diameter, and amount of extraction material used) that could affect the performance of multi‐walled carbon nanotubes were investigated. Optimization of sample preparation and determination allowed recoveries between 70.8 and 114.8% for all 37 pesticides with < 20.0% relative standard deviations at three spiking levels of 20, 50, and 200 μg/kg. The limits of quantification and limits of detection for the 37 pesticides ranged within 0.46–28.57 and 0.14–8.57 μg/kg at a signal‐to‐noise ratio of 10 and 3, respectively.     

Simultaneous determination of multiclass plant growth regulators in fruits using the quick,easy, cheap,effective, rugged,and safe method and ultra‐high performance liquid chromatography‐tandem mass spectrometry

In this study, a modified quick, easy, cheap, effective, rugged, and safe method combined with ultra‐high performance liquid chromatography and tandem mass spectrometry was developed for the multiclass determination of 28 plant growth regulators in various fruits. Different extraction solvents and adsorbents, including primary secondary amine, octadecylsilyl, graphitized carbon black, and zirconia‐based sorbent, were investigated. Internal calibration and isotope internal standards, chlormequat chloride‐d₄, mepiquat chloride‐d₆, indole‐3‐acetic acid‐d₂, and forchlorfenuron‐d₅ were used to improve accuracy. For method validation, good linearity, low limits of detection and quantification were obtained. At three spiked concentrations (10, 50, and 100 µg/kg), satisfactory recoveries with relative standard deviations of 2.4–17.5% were obtained for strawberries (75.2–119.8%), grapes (70.5–114.0%), tangerines (71.7–115.4%), apples (72.7–115.4%), and kiwi fruits (71.7–119.2%). Samples analysis revealed that 15.6% of the samples (n = 96) were contaminated with one or two kinds of plant growth regulators, including chlormequat chloride, forchlorfenuron, paclobutrazol, 2,4‐dichlorophenoxyacetic acid, 2‐diethylaminoethyl hexanoate, and mepiquat chloride. Similar results were obtained by ultra‐high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry, indicating the robustness, effectiveness, and suitability of the developed method for routine monitoring of plant growth regulator residues in fruits.     

A QuEChERS‐based extraction method for the residual analysis of pyraclofos and tebufenpyrad in perilla leaves using gas chromatography: application to dissipation pattern

The objective of this work was to establish a simple extraction method for the residual analysis of pyraclofos and tebufenpyrad in Perilla leaves. A QuEChERS (quick, easy, cheap, effective, rugged and safe) method was used for extraction using ethyl acetate as an extraction solvent, and cleanup was carried out using dispersive solid‐phase extraction technique. The samples were analyzed using gas chromatography with nitrogen phosphorous detector and confirmed by gas chromatography–mass spectrometry. The linearity was excellent (r² = 1.0) in matrix‐matched calibration for both pesticides. The recoveries at two fortification levels were 80.76–95.38% with relative standard deviation lower than 5%. The limits of detection and limits of quantification were 0.01 and 0.033 mg/kg for both pesticides, respectively. The results revealed that the dissipation pattern of pyraclofos and tebufenpyrad followed first‐order kinetics. The pyraclofos and tebufenpyrad residues declined to a level below the maximum residue limits within 14 day between the last application and harvesting. We suggest that pyraclofos and tebufenpyrad could be used efficiently on perilla leaves under the recommended dosage conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

Comparison of Different d-SPE Sorbent Performances Based on Quick,Easy, Cheap,Effective, Rugged,and Safe (QuEChERS) Methodology for Multiresidue Pesticide Analyses in Rapeseeds

Pesticide extraction in rapeseed samples remains a great analytical challenge due to the complexity of the matrix, which contains proteins, fatty acids, high amounts of triglycerides and cellulosic fibers. An HPLC-MS/MS method was developed for the quantification of 179 pesticides in rapeseeds. The performances of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method were evaluated using different dispersive solid-phase extraction (d-SPE) sorbents containing common octadecylsilane silica/primary–secondary amine adsorbent (PSA/C18) and new commercialized d-SPE materials dedicated to fatty matrices (Z-Sep, Z-Sep⁺, and EMR-Lipid). The analytical performances of these different sorbents were compared according to the SANTE/12682/2019 document. The best results were obtained using EMR-Lipid in terms of pesticide average recoveries (103 and 70 of the 179 targeted pesticides exhibited recoveries within 70–120% and 30–70%, respectively, with low RSD values). Moreover, the limits of quantification (LOQ) range from 1.72 µg/kg to 6.39 µg/kg for 173 of the pesticides. Only the recovery for tralkoxydim at 10 μg/kg level was not satisfactory (29%). The matrix effect was evaluated and proved to be limited between −50% and 50% for 169 pesticides with this EMR-Lipid and freezing. GC-Orbitrap analyses confirmed the best efficiency of the EMR-Lipid sorbent for the purification of rapeseeds.     

Rapid determination of residual pesticides in tobacco by the quick,easy, cheap,effective, rugged,and safe sample pretreatment method coupled with LC–MS

A quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample pretreatment method coupled with LC–MS was developed for the determination of 11 pesticides in tobacco. Sample pretreatment parameters and instrumental parameters of LC–MS were investigated, and the optimal conditions were selected. Under the optimized conditions, the 11 pesticides were detected simultaneously with a good linear relationship (r² = 0.9993–0.9999) and high precisions (less than 5% of the RSD of peak areas). The LODs were in the range of 0.1–5.0 μg/L. Compared with SPE clean‐up, QuEChERS greatly simplified the sample pretreatment with simple solvent extraction system. After QuEChERS pretreatment, no serious matrix effects were observed. Used for the analysis of real samples, metalaxyl was found in cigarette and tobacco samples at 63.47 and 132.27 ng/g, respectively. The recoveries for 11 pesticides were in the range of 70.03–118.69%, and RSDs were less than 10%. The proposed method is simple, low cost, and has good reproducibility.     

Development of a green miniaturized quick,easy, cheap,effective, rugged,and safe approach in tandem with temperature-assisted solidification of floating menthol droplet for analysis of multiclass pesticide residues in milk

A new green miniaturized quick, easy, cheap, effective, rugged, and safe approach was developed and used for the extraction of multiclass 16 pesticides in milk before gas chromatography analysis. The miniaturization of method reduced the consumption of chemical reagents and samples. Magnetic three-dimensional graphene was used as sorbent in the clean-up step. Choline chloride:lactic acid (1:2) natural deep eutectic solvent was used as desorption solvent. Temperature-assisted solidification of floating menthol drop was executed for preconcentration of analytes. The method parameters including sorbent, desorption solvent, sorption and desorption times, menthol amount, pH, and ionic strength were optimized. The limit of quantification and linear range were 0.03–0.38 and 0.03–250 μg/kg, respectively. The accuracy was assessed by recovery evaluation at the spike levels of 50 and 100 μg/kg, in the range of 61–119%, with relative standard deviations within 2.1–18.2%. The method was applied to the analysis of pasteurized low and high-fat bovine milk, and various pesticide residues were detected in the concentrations range of 1.24–4.68 μg/kg. Finally, the greenness of the procedure was evaluated using the Analytical Eco-Scale. This work represents the first application of hybrid miniaturized extraction/preconcentration using a natural deep eutectic solvent and menthol to analyze pesticides.     

High‐performance liquid chromatographic determination of multi‐mycotoxin in cereals and bean foodstuffs using interference‐removal solid‐phase extraction combined with optimized dispersive liquid–liquid microextraction

A novel pre‐treatment was proposed for the simultaneous determination of aflatoxins, ochratoxin A and zearalenone in foodstuffs using high‐performance liquid chromatography with fluorescence detection. The analytical procedure was based on a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure, followed by salting out and purification with a C₁₈ solid‐phase extraction column as interference removal clean‐up. Subsequently, collected supernatant was subjected to dispersive liquid–liquid microextraction. Response surface methodology based on central composite design was employed to optimize conditions in the microextraction procedure. Under the optimum conditions, satisfactory analytical performance with recoveries ranging from 63.22 to 107.6% were achieved in different types of cereals and beans, as well as desirable precisions (0.81–8.13%). Limits of detections and quantifications for these six mycotoxins ranging from 0.03 to 13 μg/kg and 0.22 to 44 μg/kg, respectively, were obtained. Finally, the established method was successfully validated by four certified reference materials (P  = 0.897 > 0.05) and applied to 79 samples from local markets.     

Multiresidue determination of 29 pesticide residues in pepper through a modified QuEChERS method and gas chromatography–mass spectrometry

This study describes the development and use of a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with gas chromatography with mass spectrometry to determine 29 pesticide residues in green, red and dehydrated red peppers. Pesticides were extracted with acetonitrile (1% acetic acid), partitioned with sodium chloride and purified with primary secondary amino and octadecyl silane in acetone. The QuEChERS extraction conditions were optimized, and the matrix effects that might influence recoveries were evaluated and minimized using matrix‐matched calibration curves. Under the optimized conditions, the calibration curves for 29 pesticides showed good linearity in the concentration range of 0.1–10 μg/mL with determination coefficient R² > 0.998. The limits of quantification of the 29 pesticides were 0.006–0.06 mg/kg for green pepper, 0.005–0.039 mg/kg for red pepper and 0.014–0.25 mg/kg for dehydrated red pepper. These values are below the suggested regulatory maximum residue limits. The mean recoveries ranged between 70.1 and 110%, and the relative standard deviations were <13%. The developed method was successfully applied to commercial samples. Some samples were found to contain the 29 pesticides with levels below the legal limits. Copyright © 2016 John Wiley & Sons, Ltd.     

Simultaneous determination of pyrametostrobin and its two metabolites in cucumber and soil using a quick,easy, cheap,effective, rugged,and safe method with HPLC–MS/MS

An easy, effective and sensitive analytical method for the simultaneous determination of a novel fungicide pyrametostrobin and its two metabolites pyrametostrobin‐M1 and pyrametostrobin‐M2 in cucumber and soil was developed using a quick, easy, cheap, effective, rugged, and safe method with high‐performance liquid chromatography and tandem mass spectrometry. The extraction solvent was acetonitrile, and cleanup sorbents were primary secondary amine and graphitized carbon black for cucumber samples and primary secondary amine for soil samples. The three target compounds were successfully separated between 3.2 and 3.9 min using a Waters CORTECS™ C₁₈ column connected to an electrospray ionization source. All the matrix‐matched samples at three fortified levels (10, 100 and 1000  μg/kg) provided satisfactory recoveries in the range of 78.8–93.8% with relative standard deviations below 6.9%. The limits of quantitation for the three compounds were below 0.183 μg/kg. The proposed method was validated by analyzing real samples.     

Development and validation of an analytical method for multiresidue determination of pesticides in lettuce using QuEChERS–UHPLC–MS/MS

A new analytical method for multiresidue determination of 16 multiclass pesticides in lettuce was developed using ultra‐high performance liquid chromatography with tandem mass spectrometry with a triple quadrupole mass analyzer and positive mode electrospray ionization, using a previously optimized quick, easy, cheap, effective, rugged, and safe method for sample preparation. Validation studies, according to document SANTE/11945/2015, demonstrated that the developed method is selective, accurate, and precise, providing recoveries of 70–120%, relative standard deviations ≤20% and quantification limits from 3 μg/kg. The method was compared with one based on high‐performance liquid chromatography with tandem mass spectrometry, in terms of chromatographic performance, detectability and matrix effect for five varieties of lettuce. The new method provided a reduction in the time for the chromatographic analysis of 50%, from 30 to 15 min, using a lower mobile phase flow rate (0.147 mL/min), which reduced the consumption of mobile phase by 25%, and injection of smaller amounts of sample (1.7 μL). Lower limits of quantification were obtained for almost all pesticides studied for green‐leaf lettuce. However, in relation to the matrix effect, four of the five types of lettuce studied presented higher matrix effects.     

Rapid screening of amitraz and its metabolite residues in honey using a quick,easy, cheap,effective, rugged,and safe extraction method coupled with UHPLC and Q Exactive

A method for determining amitraz and 2,4‐dimethylaniline in honey was established by using ultra‐high‐performance liquid chromatoghaphy and Q Exactive after applying quick, easy, cheap, effective, rugged, and safe extracting process. A suitable extraction method was designed to extract the amitraz and 2,4‐dimethylaniline after a suitable amount of honey samples was dissolved. A Thermo Syncronis C₁₈ column (100 × 2.1 mm, 1.7 μm) was used for chromatographic separation of the samples. Then the two compounds were quantitatively analyzed via a program of Q Exactive. The linearity of amitraz and 2,4‐dimethylaniline was good in the concentration range of 0.5–100 μg/L, and the correlation coefficient R² was >0.99. The average recovery and relative standard deviation of each component were 81.3–90.0% and 5.1–7.2%. The 24‐ and 48‐h test results showed that the sample needed to be tested within 24 h. The limit of detection was 0.1 μg/kg for amitraz and 2,4‐dimethylaniline, whereas for both the limit of quantitation was 0.3 μg/kg.     

Multiresidue analysis of 36 pesticides in soil using a modified quick,easy, cheap,effective, rugged,and safe method by liquid chromatography with tandem quadruple linear ion trap mass spectrometry

A new method for simultaneous determination of 36 pesticides, including 15 organophosphorus, six carbamate, and some other pesticides in soil was developed by liquid chromatography with tandem quadruple linear ion trap mass spectrometry. The extraction and clean‐up steps were optimized based on the quick, easy, cheap, effective, rugged, and safe method. The data were acquired in multiple reaction monitoring mode combined with enhanced product ion to increase confidence of the analytical results. Validation experiments were performed in soil samples. The average recoveries of pesticides at four spiking levels (1, 5, 50, and 100 μg/kg) ranged from 63 to 126% with relative standard deviation below 20%. The limits of detection of pesticides were 0.04–0.8 μg/kg, and the limits of quantification were 0.1–2.6 μg/kg. The correlation coefficients (r²) were higher than 0.990 in the linearity range of 0.5–200 μg/L for most of the pesticides. The method allowed for the analysis of the target pesticides in the lower μg/kg concentration range. The optimized method was then applied to the test of real soil samples obtained from several areas in China, confirming the feasibility of the method.