Modified Quick, Easy, Cheap, Effective, Rugged, And Safe Method Research Articles

Determination of chlorothalonil in vegetables/fruits using liquid chromatography-tandem mass spectrometry with a discharge adapter interface.

Chlorothalonil (CHT), a broad-spectrum fungicide, has been employed widely to control foliar diseases, whereas with a major metabolite of polar 4-hydroxychlorothalonil (CHT-4-OH), only an acceptable nonpolar CHT residue is allowed by most countries. This study involves the method development for CHT residue in vegetables/fruits using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with a novel modified discharge-adaptor (DA) interface. CHT residue was analyzed using LC-MS/MS with DA interface (LC-DA-MS/MS), developed in our previous works. A DA was placed on the electrospray tip to switch the ionization modes. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was applied to extract CHT residue of vegetables/fruits efficiently with less sample preparation time and analysis cost. CHT and CHT-4-OH spiked in four different vegetables/fruits were extracted using the modified QuEChERS method. After LC with isocratic elution, CHT and CHT-4-OH were separated within 3min. Using LC-DA-MS/MS, the ion signals of CHT were improved two to three times, and the limit of quantification of 5ng/g and linearity (r2 > 0.99) in the range of 5-200 ng/g were achieved using 10g of vegetables/fruits. The precision and accuracy were within 15% each. The modified QuEChERS and LC-DA-MS/MS were applied to examine eight field-grown vegetables/fruits; 9.5 and 2588.9ng/g of CHT were detected in two vegetables/fruits. LC-DA-MS/MS combined with modified QuEChERS was successfully applied to determine CHT residue <10ng/g in vegetables/fruits and with satisfied validation results. The developed method could reduce both analysis cost and time, attributing to simplifications in modified QuEChERS, isocratic elution, and DA interface in LC-DA-MS/MS.

Validation of a modified QuEChERS method for the quantification of residues of currently used pesticides in Cuban agricultural soils, using gas chromatography tandem mass spectrometry

We present an analytical method to detect and quantify residues of currently used pesticides (CUPs), which include 31 active ingredients (ai) and seven transformation products (TPs) in tropical and agricultural soils of Cuba. Ten isotopically labeled analogous compounds served as internal standards (IL-IS). The novelty of this research is the inclusion of different tropical soils type scarcely studied for CUPs and TPs, based on the QuEChERS (quick, easy, cheap, effective, rugged and safe) method, followed by chromatography tandem mass spectrometry. All figures of merit proved to be satisfactory according to SANTE guidelines 2020 and 2021. Matrix effects (ME) calculated by the external standard method were significant (|ME| > 20% for almost all compounds; grand mean ± standard deviation (STD) 104 ± 108%) in all soils. The internal standard method compensated ME to non-significant levels (8 ± 50%), even for analytes with a non-structure identical IL-IS (STD, 13 ± 57%). Repeatability (relative standard deviation, RSDr) and reproducibility (RSDR) for skeletic regosol (SR) were 7.5 ± 2.8% and 11.7 ± 4.7%, respectively. Absolute (quantified for 11 analytes with structure identical IL-IS) and relative recovery from SR was 92 ± 13% (mean ± STD) and 90 ± 12%, respectively. Limits of quantification for SR ranged from 0.1 to 10 ng/g, except metalaxyl and oxyfluorfen (25 ng/g each). Linearity of matrix-matched (MM) calibration curves (5 to 100 ng/g) had an R2 of ≥ 0.99 for all soils and almost all analytes. The method was successfully applied to 30 real soil samples.

Determination of teicoplanin and ramoplanin residues in aquaculture products by a modified QuEChERS method combined with UPLC-MS/MS

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was developed to provide good analytical results for teicoplanin (TEC) and ramoplanin (RAM) residues in aquaticproducts. The analytes was extraction from aquatic product samples using chitosan in the QuEChERS procedure. Compared to conventional adsorbents, chitosan has a relatively good purification ability for the targets.The matrix effects of aquatic products, such as crucian carp, carp, silver carp, tilapia, mandarin fish, turbot, shrimp, sea cucumber and so on, were evaluated by high performance liquid chromatography coupled to triple-quadrupole tandem mass spectrometry. Throughout the validation experiments, the limits of detections and quantifications ranged from 0.4 ∼ 0.8 μg kg−1 and 1.0 ∼ 3.0 μg kg−1, respectively. Calibration curves showed correlation coefficient values higher than 0.998 in range between 1 and 100 μg kg−1. The recoveries ranged from 89.8 % to 110.0 % with relative standard deviation less than 7.2 % in nine typical aquaticproducts. The method shows low matrix effect (-18.5 %∼-2.6 %) for all targets in different aquaticproducts. The proposed methods proved to be reliable, effective and enables rapid determination of large batch samples, indicating its good applicability for detection and monitoring of TEC and RAM residues in aquaticproducts.

Establishment of a GC-HRMS-IDMS-based modified QuEChERS approach for rapid, reliable, and simultaneous determination of organochlorine pesticides in soil

Organochlorine pesticides (OCPs), a class of organic pollutants, are highly toxic and persistent in soil and can have harmful effects on humans, organisms, and agricultural environments when bioaccumulated through the food chain. The existing methods for OCP analysis are complex and time consuming; thus, developing a rapid and reliable method for quantifying and monitoring soil-bound OCPs is essential. This study demonstrates the feasibility of replacing the existing official method for OCP analysis with a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method based on GC-HRMS-IDMS. In this modified QuEChERS method, acetonitrile was replaced with ethyl acetate as the extraction solvent. We also assessed the optimal extraction salt (Original, AOAC, and EN) and dispersive solid-phase extraction clean-up sorbent. The limits of detection (LODs) and quantification (LOQs) of the modified QuEChERS method for 24 OCPs ranged from 0.02 to 0.24 ng/g and from 0.06 to 0.3 ng/g, respectively. The recovery rates at the LOQ level were 59.6–115.9 % for the Original method, 60.5–112.5 % for the AOAC method, and 59.6–115.9 % for the EN method. Furthermore, soil samples contaminated with endosulfan were analyzed using the three QuEChERS methods to compare their contents and deviation. EN exhibited more accurate results than Original and AOAC. Thus, the sample processing method using QuECHERS can replace the existing method.

A modified QuEChERS sample processing method for the determination of per- and polyfluoroalkyl substances (PFAS) in environmental biological matrices

QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample processing methods have previously been applied to a range of compounds and matrices. This study presents a modified QuEChERS sample processing method that was validated and employed for 24 per- and polyfluoroalkyl substances (PFAS) for various biological matrices. PFAS are a group of synthetic chemicals that have attracted substantial attention as some compounds are acknowledged to be persistent, toxic, and bioaccumulative. It is crucial to determine PFAS in diverse environmental matrices. Currently, limited sample processing methods for PFAS in biological matrices are available and the majority only focus on a few compounds such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Thus, there is a demand to develop a sample processing method which is effective for many commonly tested PFAS compounds in environmental biological samples. In this study, the detailed sample processing procedures and method performance are described. The highlights of this method are:•The extraction solvent and salts were adjusted for PFAS extraction from environmental biological matrices.•The modified QuEChERS method is effective for extraction and cleanup from a variety of matrices including algae, plants, invertebrates, amphibians, and fish.

Optimization of modified QuEChERS method for extraction of selected pharmaceuticals from vegetable samples using HPLC

&#x0D; ABSTRACT. Optimized QuEChERS (quick, easy, cheap, effective, rugged and safe) method of sample preparation was employed for five selected pharmaceutical compounds on its advantage of simplicity, less extraction solvent and extraction time. Different parameters affecting the extraction efficiency of the target analyte was optimized. Since QuEChERS was developed for pesticides, uses of the method for pharmaceuticals need modification and evaluation of different parameters. Clean-up sorbents were evaluated for their matrix effect removal after extraction and a combination of d-SPE sorbent, MgSO4, PSA, C18 and diatomaceous earth found to be selective clean-up sorbent for the targeted compounds. The addition and amount of diatomaceous earth and EDTA during the clean-up and extraction steps, respectively, were also examined and the amount was optimized. Solvent type and composition, salt type and extraction time were also optimized and methanol, MgSO4 with NaCl salt and 5 min extraction time was obtained. The method was successfully applied to different vegetable samples collected from Addis Ababa, Ethiopia and Johannesburg, South Africa (carrot, cabbage and lettuce) and none of the target analytes were found in the sample investigated. The matrix effect study on vegetable samples collected was found very high that suppresses the signal during analysis.&#x0D; &#x0D; KEY WORDS: QuEChERS, EDTA, Pharmaceuticals, Vegetable, HPLC&#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(4), 831-844. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i4.3

Determination and risk assessment of 31 pesticide residues in apples from China's major production regions

The presence of pesticide residues in apple fruit raises serious health concerns. In multi-residue pesticide analysis, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method has gradually replaced less efficient traditional extraction methods. This study developed a modified QuEChERS method coupled with ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to simultaneously detect the residue of multiple pesticides in apple fruit. The method exhibited high linearity (R2 ≥ 0.99), and excellent recoveries (74.4–118.1 %) for 31 pesticides with relative standard deviations below 20 %. The limit of detection and limit of quantification were 0.1–4.0 μg/kg and 2.0–10.0 μg/kg, respectively. By using the established method, 20 pesticides were detected in 152 'Fuji' apple samples collected from the orchards of 17 cities in two major apple production regions of China, with an overall detection rate of 58.6 %. The residue levels were below the maximum levels set by GB 2763–2019. Moreover, both the chronic dietary intake risk (%ADI) and the acute dietary intake risk (%ARfD) for all the detected pesticides were lower than 100 %, indicating that the dietary intake risks are acceptable and would not pose potential health risks.

Determination of amphenicol antibiotic residues in aquaculture products by response surface methodology modified QuEChERS method combined with UPLC-MS/MS

A simple and sensitive method for the determination of amphenicol antibiotic (chloramphenicol, thiamphenicol and florfenicol) residues in aquaculture products was developed based on a response surface methodology-modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The pretreatment method was optimized via single-factor experiments and response surface methodology based on central-composite design to maximize the extraction efficiency and purification effect. The results show that chloramphenicol, thiamphenicol and florfenicol had good linearity in the range of 0.1–50 ng/mL. The recoveries of these amphenicol antibiotics in 12 types of aquaculture products ranged from 78.6% to 106.2% with relative standard deviations less than 12.1%. The method had high sensitivity with the limit of quantification of analytes being 0.01–0.04 μg/kg. Finally, the developed method was used to analyze actual samples. The results show that this method has good application potential for detecting residues of amphenicol antibiotics in aquaculture products.

Simultaneous Determination of Pyrethroid Insecticides in Foods of Animal Origins Using the Modified QuEChERS Method and Gas Chromatography-Mass Spectrometry.

Pyrethroid insecticides are used in agriculture to treat parasites in livestock. This study developed a simultaneous residue analysis method to measure seventeen pyrethroid insecticides in foods of animal origin, including beef, pork, chicken, milk, and eggs. The method, which comprises instrumental analysis using gas chromatography-tandem mass spectrometry and a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for pretreatment, was optimized to verify the applicability of the method. A mixture of acetonitrile, ethyl acetate, and original salt (MgSO4 4 g, NaCl 1 g) was used as the extraction solvent and salt. MgSO4 (150 mg) primary secondary amine (25 mg) and graphitized carbon black (25 mg) were selected for dispersive solid phase extraction (d-SPE). The method limit of quantitation was 0.01 mg/L, and the linearity of the matrix-matched calibration curves was reasonable (R2 &gt; 0.99). Recovery tests were performed at three concentrations (LOQ, 10 LOQ, and 50 LOQ). Good recoveries (75.2109.8%) and reproducibility (coefficient of variation &lt;10%) were obtained. The matrix effects were in the range of -35.8 to 56.0%. The established method was fully validated and can be used as an official analytical method for quantifying pyrethroid insecticides in animal commodities.

Development and validation of a modified QuEChERS method for extracting polychlorinated biphenyls and organochlorine pesticides from marine mammal blubber

The monitoring of legacy persistent organic pollutants (POPs) in blubber of key sentinel marine mammal species has been conducted using established techniques for decades. Although these methods for polychlorinated biphenyl (PCB) and organochlorine (OC) pesticide determination provide accurate and reproducible results, they possess some drawbacks in terms of cost, time, and a need for large volumes of toxic solvents. QuEChERS (quick, easy, cheap, effective, rugged, and safe) extractions may help address these issues, but have not been applied to marine mammal blubber/adipose. As such, our aim was to develop, validate, and apply a QuEChERS method for the extraction of PCB and OC contaminants in marine mammal blubber. First, we tested multiple solid-phase extraction and clean-up steps to find the approach that provided the cleanest extracts along with consistent and acceptable analyte recovery, accuracy, and precision. QuEChERS extractions followed by two enhanced matrix removal-lipid (EMR-lipid), one primary-secondary amine (PSA), and one silica gel clean-up showed the highest matrix removal and acceptable recoveries of spiked internal (62–97%) and external standards (61–94%). Solvent usage was reduced by ∼393% and extraction time was reduced by ∼25% (from 16 to 12 h). Next, the method was validated using standard reference material (SRM) NIST 1945. Recovery experiments on SRM (n = 5) showed acceptable recovery for 76% and 77% of PCBs and OC pesticides, respectively, and high precision for 73% and 69% of PCBs and OCs, respectively. Finally, the method was used on a set of southeast Greenland killer whales (n = 13), with previously published PCB and OC data. Bland-Altman plots indicated good agreement between QuEChERS and current-use methods for ΣPCBs and some OCs with no significant constant or proportional bias. These results demonstrate that this QuEChERS extraction method represents an effective, lower cost alternative to current-use extractions for PCBs and OCs in blubber, and likely other high-lipid samples.

Validation of modified QuEChERS method for metformin and triclosan quantification in sewage using LC-MS

ABSTRACT The compounds in pharmaceutical and personal care products (PPCPs) that may be potential environmental pollutants include metformin and triclosan. The suitable method to estimate the presence of metformin (MET) and triclosan (TRI) in wastewater treatment facilities is developed and validated in this research study. This study aimed to quantify the MET and TRI in sewage through a liquid chromatograph – mass spectrometer (LC-MS 8040) by a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) technique of sample preparation. In LC-MS 8040, the Milli-Q water and sewage were examined at three different concentrations (0.01, 0.02 and 0.03 mg L−1) of MET and TRI. The recoveries of MET in both the matrixes ranged between 88.10 to 116.10% whereas the recoveries were ranged from 86.70 to 116.30% for TRI (n = 7, RSD <10%). The respective limit of detection (LOD) and the limit of quantification (LOQ) for MET and TRI were 0.005 and 0.01 mg L−1. With the matrix effect of < 10% in sewage, the approach was shown to be very linear (R2 = 0.9969 for MET and R2 = 0.9939 for TRI) and reliable. The precision was also exemplary with the RSD value of < 10% (n = 6). This method accurately assessed MET (BDL to 0.0657 mg L−1) and TRI (BDL to 0.1833 mg L−1) concentrations in sewage samples of Ukkadam sewage treatment plant (USTP) and Tamil Nadu Agricultural University treatment plant (TSTP). This is a unique use of the QuEChERS method for calculating these two compounds from aqueous matrixes with substantially greater outputs (20–25 samples per day) than typical Solid Phase Extraction (SPE) procedures.

Development and Validation of a Modified QuEChERS Method for Simultaneous Analysis of 250 Flavor Constituents in Tobacco by Gas Chromatography Tandem Mass Spectrometry.

Flavor constituents play an important role in the flavor characteristics of tobacco leaves and cigarettes. Sensitive, selective, and high-throughput multi-analyte analytical methods are needed to satisfy the demand for analyzing trace-level flavor constituents in tobacco. However, trace analysis of multi-targets in a complex tobacco matrix is significantly challenging. This study was undertaken to develop and validate a fast, selective, sensitive, and accurate GC-tandem mass spectrometry (GC-MS/MS) method for the simultaneous analysis of 250 flavor constituents in tobacco using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction procedure and backflushing technique. The samples were extracted with a mixture of acetonitrile and phosphate buffer. GC-MS/MS served as a reliable tool to quantify the flavor constituents due to its high sensitivity, selectivity, and good repeatability. Our evaluation showed that 243 flavor constituents presented good linearity. Average recoveries of 216 target compounds in tobacco ranged from 70 to 120% with RSDs less than 20% at three fortification levels. The limits of quantitation of 225 and 25 compounds were in the range of 2-50 and 51-112 μg/kg, respectively. This method was then successfully applied to the analysis of 15 commercial cigarette samples with different style characteristics. The modified QuEChERS method worked very well for a wide range of flavor constituents that have not been reported by QuEChERS pretreatment previously, and the use of concurrent backflushing offered significant increase in system robustness and sample throughput. The method greatly improved the detection performance and the range of the flavor constituents, and proved to be more accurate, sensitive, selective, convenient, and practical than the reported method, and thus, can be applied in routine analysis. A validated QuEChERS-based GC-MS/MS method for multiple flavor constituents analysis in tobacco was reported for the first time. The use of concurrent backflushing markedly improved the instrument robustness and sample throughput.

Validation of a modified QuEChERS method for the extraction of multiple classes of pharmaceuticals from soils

BackgroundThe quick, easy, cheap, effective, rugged, and safe (QuEChERS) method can be employed for multi-residue analyses instead of traditional extraction methods due to its advantages in terms of extraction time and required equipment. A modified version of the QuEChERS method has been developed for quantifying eight pharmaceuticals belonging to different classes in three real soils with different chemical properties. Firstly, the soils have been polluted with all contaminants and the recoveries were determined by liquid chromatography tandem–mass spectrometry. Due to similar recoveries from the three soils, the validation of the method has been carried out only on a soil by determining linearity, recovery, precision, limit of detection (LOD) and limit of quantification (LOQ) values. A matrix-matched calibration for the soil has been adopted in order to avoid the matrix effect and three levels of fortification (50, 100 and 500 µg L−1) were used.ResultsThe recovery of all pharmaceuticals, with the exception of tetracycline, from any soil was between 72 and 113%. In the validation procedure, recoveries of fortified samples ranged from 80 to 99%, the relative standard deviations ranged between 1.2 and 11.8%, and the LOQ between 20 and 36.9 μg kg−1.ConclusionThe results of the present study confirmed the validity of the modified QuEChERS method for the extraction of pharmaceuticals from soils in the range 50–500 μg kg−1.Graphical

Simultaneous Determination of Six Immunosuppressants in Human Whole Blood by HPLC-MS/MS Using a Modified QuEChERS Method.

A high-performance liquid chromatography-tandem mass spectrometry method was established for the simultaneous determination of mycophenolic acid, mycophenolate mofetil, tacrolimus, rapamycin, everolimus and pimecrolimus in human whole blood by optimizing the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) preparation method. Whole blood was extracted into ethyl acetate, salted out with anhydrous magnesium sulfate, and purified with ethylenediamine-N-propyl silane adsorbent. The supernatant was evaporated under nitrogen until dry and finally reconstituted in methanol. Chromatographic separation was performed on an Agilent Poroshell 120 EC-C18 column in methanol (mobile phase A)-water (optimized for 0.1% acetic acid and 10 mM ammonium acetate, mobile phase B) at a 0.3 mL·min−1 flow rate. Electrospray ionization and positive ion multiple reaction monitoring were used for detection. The time for of analysis was 13 min. The calibration curves range of tacrolimus, rapamycin, everolimus and pimecrolimus were in the range of 1–100 ng·mL−1, mycophenolate mofetil in the range of 0.1–10 ng·mL−1 and mycophenolic acid at 10–1000 ng·mL−1. All correlation coefficients were >0.993. The coefficients of variation (CV, %) for inter-day and intra-day precision were less than 10%, while the spiked recoveries were in the range of 92.1% to 116%. Our method was rapid, sensitive, specific, and reproducible for the simultaneous determination of six immunosuppressants in human whole blood. Importantly, our approach can be used to monitor drug concentrations in the blood to facilitate disease treatment.

Determination of 250 pesticide residues in the Iranian vegetables assessed during 2019–2020 using the modified QuEChERS method along with gas chromatography - mass spectrometry

In this study, association of official agricultural chemists(AOAC) international (2007) QuEChERS (quick, easy, cheap, effective, rugged,and safe) method was developed with slight changes under the term of the modified QuEChERS method and was used along with gas chromatography–mass spectrometry (GC–MS) for determination of 250 selected multiclass pesticides in vegetables (in total of 1436 samples) during 2019 - 2020 in iran. The principles of this method are similar to the conventional QuEChERS method and involve extraction of acetonitrile, followed by the dispersed solid-phase extraction (SPE) purification with a combination of primary-secondary amine (PSA) adsorbent and MgSO4 but with slight changes in steps of sample preparation and volume of organic solvent and amount of adsorbent. For performance evaluation, validation method was carried out. After applying changes and experiments, recovery yields ranged from 77.1 to 113.2%, with repeatabilities of 4.4–19.2%. The limits of detection (LODs) were between 0.0016 - 0.044 for target analytes in extract of vegetable samples. The expanded measurement uncertainty was not higher than 30% for all target analytes. The method was successfully applied for analysis of 1,436 vegetable samples obtained from local markets and vegetable traders. There were no residues in 69.76% of samples. A portion (25.49%) of the samples contained pesticide residues less than or equal to the maximum residue limits (MRLs), and 4.94% of samples contained pesticide residues greater than their MRLs. Our findings provided useful information on the current contamination status of a key agricultural area in iran from 2019 to 2020 and highlighted the need for regular monitoring of pesticide residues in a greater number of vegetable samples for longer periods.

Development of a High-Throughput Screening Analysis for 195 Pesticides in Raw Milk by Modified QuEChERS Sample Preparation and Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry

This study aimed to develop a simple, high-throughput method based on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) followed by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) for the rapid determination of multi-class pesticide residues in raw milk. With acidified acetonitrile as the extraction solvent, the raw milk samples were pretreated with the modified QuEChERS method, including extraction, salting-out, freezing, and clean-up processes. The target pesticides were acquired in a positive ion electrospray ionization mode and an All ions MS/MS mode. The developed method was validated, and good performing characteristics were achieved. The screening detection limits (SDL) and limits of quantitation (LOQ) for all the pesticides ranged within 0.1–20 and 0.1–50 μg/kg, respectively. The recoveries of all analytes ranged from 70.0% to 120.0% at three spiked levels (1 × LOQ, 2 × LOQ, and 10 × LOQ), with relative standard deviations less than 20.0%. The coefficient of determination was greater than 0.99 within the calibration linearity range for the detected 195 pesticides. The method proved the simple, rapid, high throughput screening and quantitative analysis of pesticide residues in raw milk.

A porous boron nitride nanorods-based QuEChERS analysis method for detection of five neonicotinoid pesticide residues in goji berries

To accurately determine neonicotinoid pesticide residues in goji berries, porous boron nitride nanorods (p-BNNRs) were prepared and used as a new QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) clean-up sorbent. Combined with ultrahigh-pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), a modified QuEChERS method was developed to determine five neonicotinoid pesticide residues in goji berries. In goji berries, the p-BNNRs were shown to have a greater clean-up ability than typical clean-up materials (C18, PSA) The recoveries of the five targets ranged from 78.1 to 117.3% at three fortified levels, and the LODs ranged from 2.2 to 3.7 μg kg−1. The results indicate that this approach could be successfully used to quickly determine of the five neonicotinoid insecticide residues in goji berries for risk assessment purposes, demonstrating the applicability and suitability of p-BNNRs for the routine evaluation of neonicotinoid insecticide residues in goji berries.

Magnetic mesoporous material derived from MIL-88B modified by l-alanine as modified QuEChERS adsorbent for the determination of 6 pesticide residues in 4 vegetables by UPLC-MS/MS

More and more attention has been paid to the improved QuEChERS (quick, easy, cheap, effective, rugged and safe) method in dealing complex sample matrices, especially for the study of QuEChERS adsorbents. In this study, a magnetic mesoporous material, which was derived from MIL-88B modified by l-alanine, was synthesized as modified QuEChERS adsorbents for the simultaneous determination of multiple pesticides (Methomyl, Isoprocarb, Carbofuran, 3-Hydroxycarbofuran, Acetamiprid, Imidacloprid) in Chinese cabbage, celery, long bean and leek. The prepared magnetic adsorbents can effectively remove interfering substances from the sample, and the proposed modified QuEChERS method can reduce sample pretreatment time via an external magnetic field. To achieve the best performance of QuEChERS method, the clean-up time and amount of QuEChERS adsorbents were investigated. Under the optimized conditions, a simple, rapid and sensitive method for the determination of 6 pesticide residues in vegetables was established by coupling the modified QuEChERS to ultrahigh-performance liquid chromatography-tandem mass spectrometry. Excellent sensitivity (The limit of detection for the 6 pesticides ranged from 0.001 to 0.020 µg kg−1), satisfactory linearity (r2 ≥ 0.9952), good recovery (73.9–107.7%) and good precision (3.6–16.9% for intraday relative standard deviation, 0.5–15.0% for interday relative standard deviation) were obtained. Compared with traditional QuEChERS method, the proposed method is simple, cost-effective, and efficient, which indicates that the method can be used to detect carbamate and neonicotinoid pesticides in real samples and provide an excellent pretreatment technique for the detection of trace multi-analytes from complex substrates.

Multiresidue pesticide analysis in tomato using GC-MS/MS using modified QuEChERS method with titanium-coated graphite with CNT-ABS nanocomposite as dispersive solid-phase extraction materials

Abstract The presence of pesticide residues in food and vegetables is a growing concern for consumers. To monitor these residues reliably, a selective and sensitive multiresidue system has been developed and validated in tomato by gas chromatography–tandem mass spectrometry (GC-MS/MS). Titanium-coated graphite with carbon nanotube (CNT) in acrylonitrile–butadiene–styrene (ABS) used as reversed-dispersive solid-phase (extraction materials with modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method. Titanium-coated graphite with CNT-ABS is synthesized, characterized by X-ray diffraction and scanning electron microscopy. The clean-up performance of titanium-coated graphite with CNT-ABS was demonstrated to be better to primary secondary amine and graphitized carbon black cartridges. The processing of two multiple reaction monitoring transformations for each analyte is done using GC-MS/MS in electron impact mode. Satisfactory purification and recovery effects (74%–100%) of 35 pesticides were achieved in tomato matrices when using 5 mg of titanium-coated graphite ABS-CNT nanocomposite. It was observed that quinolphos and deltamethrin are present above the maximum residue limit. The technique proved to be reliable and sensitive in tomato samples for the routine testing of 35 pesticides.

Rapid determination of multi-antibiotic residues in honey based on modified QuEChERS method coupled with UPLC–MS/MS

Antibiotic residues in honey cause public health problems. To analyze multi-antibiotic residues in honey, a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction method coupled with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed for simultaneous quantification of 70 antibiotic residues in honey. Matrix-matched calibrations indicated the correlation coefficients were higher than 0.998. The recovery was in a range of 70.5%-119.8% with intra-day relative standard deviation (RSD) of ≤ 10.0% and inter-day RSD of ≤ 13.9%. The limits of detection ranged between 0.050 μg/kg and 1.02 μg/kg. Limits of quantification was 0.17 μg/kg to 3.40 μg/kg. The matrix effects were negligible in 71.4% of compounds and moderately in 24.3% of compounds. Methacycline, oxytetracycline, tetracycline and its metabolite 4-tetracycline residues were detected in the tested samples. Validation parameters were acceptable and were in line with the Codex guidelines. This method was effective for detecting multi-antibiotic residues in honey.