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

Determination of Perfluorocarboxylic Acids and Perfluorosulfonic Acids in Aquatic Products by Quick, Easy, Cheap, Effective, Rugged, and Safe Sample Preparation with Liquid Chromatography-Tandem Mass Spectrometry

A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed for the simultaneous determination of 12 perfluorocarboxylic acids (PFCAs) and 7 perfluorosulfonic acids (PFSAs) in the muscle of shrimp, shellfish, and fish. A modified QuEChERS procedure was applied to the extraction and concentration of perfluorinated compounds (PFCs) as well as for removal of interferences. The determination of the 19 PFCs was performed by LC-MS/MS in negative-ion detection mode. 13C-labeled PFCs, as a stable isotopic internal standard (except for L-PFBS, L-PFPeS, ipPFNS, and L-PFNS, for which no labeled analogs were available), was used for calibration. The limits of detection ranged from 0.01–1.0 μg/kg. The recoveries of spiked sample at 0.02–8.0 μg/kg ranged from 61 to 117% with relative standard deviations of less than 14%. The developed method was successfully utilized to monitor real samples, which demonstrated that it is a simple, fast, and robust method and could be used to monitor PFCAs and PFSAs in aquatic products. Most of the samples tested positive, mainly for perfluorooctane sulfonate acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutanoic acid (PFBA), but other samples of the 14 studied PFCs were also present.

Simultaneous analysis of mycotoxins in corn flour using LC/MS-MS combined with a modified QuEChERS procedure

The present study was developed to simultaneously quantify different mycotoxins including zearalenone (ZEA), T2-toxin, aflatoxin B1 (AFB1), deoxynivalenol (DON), and ochratoxin A (OTA) in 30 and 10 corn flour samples collected from local gristmill corn in Ardabil province and local markets in Tehran, respectively. A modified method QuEChERS (quick, easy, cheap, effective, rugged, and safe) in combination with an LC-MS/MS technique was used for sample preparation and measuring the levels of mycotoxins, respectively. Spiked calibration curves based on external and internal standards were used to overcome matrix effects and were reported as linear between 2 and 50 ng g−1 for aflatoxin B1, T-2 toxin, ochratoxin A; 50 and 1250 ng g−1 for zearalenone; and 75 and 1800 ng g−1 for deoxynivalenol. With the aid of spike calibration curves and acidic condition, the absorption of OTA by primary, secondary amine was reduced, and consequently, the percentage of recoveries was improved (in the range of 92.98–103.8). AFB1, OTA, and ZEA were detected and quantified in 23 (76.6%), 6 (20%), and 14 (46%) of 30 samples, with average contamination of 154.1 ng g−1, 25 ng g−1, and 358.7 ng g−1, respectively. The co-occurrence of AFB1 + ZEA and AFB1 + OTA + ZEA was noted in 20% and 23% of corn samples, respectively. The measured level of contamination for DON and T-2 toxin of corn flour samples did not exceed the maximum tolerated level. Moreover, the estimation of dietary intake of AFB1, OTA, ZER, DON, and T2-toxin were 5.8, 1.1, 32.1, 5.58, and 0.06 ng per kg body weight per day, respectively.

Simultaneous Determination of Plant Growth Regulators in Fruit by Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with Modified QuEChERS Procedure

Abstract Five plant growth regulators, uniconazole, 6-benzyladenine, kinetin, 4-chlorophenoxyacetic acid and diethyl aminoethyl hexanoate, frequently used in apple, grape, strawberry, peach and orange, were determined by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). A modified QuEChERS (Quick, easy, cheap, effective, rugged and safe) procedure was used in sample pretreatment, which involved extraction with acetonitrile containing 1% acetic acid and clean-up with a mixture of ODS and MgSO4. Mass spectrometric determination was performed in multiple reaction monitoring mode (MRM) using external standards for calibration. The results indicated that the calibration curves for the target analytes were linear in the range of 1–100 μg L−1 with correlation coefficients greater than 0.999. The recoveries at three spiked levels ranged from 71.82% to 109.24% with RSDs from 0.57% to 12.43%. The respective limits of detection (LOD) and limits of quantification (LOQ) were 0.15–0.45 μg kg−1 and 0.51–1.50 μg kg−1 for uniconazole, 0.28–0.53 μg kg−1 and 0.94–1.75 μg kg−1 for 6-benzyladenine (6-BA), 0.15–69 μg kg−1 and 0.51–2.29 μg kg−1 for kinetin (6-KT), 0.22–0.60 mu;g kg−1 and 0.74–2.01 μg kg−1 for 4-chlorophenoxyacetic acid (4-CPA), 0.88–1.89 μg kg−1 and 2.89–6.29 μg kg−1 for diethyl aminoethyl hexanoate (DA-6).

Cleaning Up Vegetable Samples Using a Modified “QuEChERS” Procedure for the Determination of 17 Plant Growth Regulator Residues by Ultra High Performance Liquid Chromatography–Triple Quadrupole Linear Ion Trap Mass Spectrometry

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample pretreatment method coupled with ultra high performance liquid chromatography–triple quadrupole linear ion trap mass spectrometry (UHPLC-QTrap-MS/MS) was developed for simultaneous determination of 17 plant growth regulator (PGR) residues in vegetables. Generik ChlorF (GCF) was used as one of the adsorbents in modified QuEChERS procedure, which can selectively remove the chlorophyll of acetonitrile extract without causing the losses of PGRs that have planar structure. To achieve the optimum performance toward the target analytes, extraction solvent, the type of adsorbent, and the amount of the adsorbent were investigated. Under the optimized conditions, good linearities with correlation coefficients (γ) higher than 0.9954 were obtained. The new method provided sufficient sensitivity as reflected by the values of limit of detection (LOD) and limit of quantification (LOQ). The LOD varied between 0.01 and 0.70 μg/kg and the LOQ varied between 0.04 and 2.32 μg/kg. Acceptable recoveries ranging from 78.5 to 116.8 % with the relative standard deviations (RSDs) of 0.9–11.9 % were achieved. The evaluated method provided reliable screening, quantification, and identification of 17 PGRs in vegetables.

Simultaneous Determination of 27 Pesticides in Ginseng by UPLC/MS/MS and Modified QuEChERS Procedure

A novel, simple, and rapid method for the quantification of 27 commonly used pesticides in ginseng incorporating a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure was developed and validated. The pesticides were extracted with 1% acetic acid in acetonitrile and extracts purified by use of the mixed sorbents primary-secondary amine, C18, and graphitized carbon black. Quantitative analysis of all pesticides was performed by ultra-performance LC/MS/MS in the positive ionization mode in a single run due to the fast polarity switching capability of the mass spectrometer. Two precursor-product ion transitions were monitored for each compound in the multiple reaction monitoring mode. Quantification was carried out using matrix-matched standards for calibration. Recoveries of the proposed method from the spiked samples were achieved in the range 62.8-108.5%, and RSD ranged from 1.5 to 11.8%.

Multi-residue screening of 100 multi-class veterinary drugs in milk powder by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

In this study, a simple and rapid multi-residue screening method for the quantification and confirmation of 100 multi-class veterinary drugs in milk powder by the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method combined with liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was developed. The veterinary drugs investigated belonged to several families such as macrolides, sulfonamides, quinolones, tetracyclines, nitroimidazoles, benzimidazoles, β-agonists, hormones, and tranquilizers. The samples were extracted using a modified QuEChERS procedure: (i) dissolved in a solution of Na2EDTA–McIlvaine buffer (0.1 M, pH 4), (ii) extracted with 5% acetic acid in acetonitrile, and (iii) purified using a C18 sorbent. The linearity, sensitivity, accuracy, repeatability, and reproducibility of the method were fully validated. The average recoveries for the majority of analytes (92.9%) ranged from 70 to 120% at four concentration levels, while the repeatability and reproducibility ranged from 1.1 to 20.1%. A coefficient of correlation (γ2) of 0.995 or above was obtained for all the compounds. The range of the limit of quantification for these compounds in the milk powder was from 0.1 to 25 μg kg−1. More than 93.0% of the analytes were detected when present at 10 μg kg−1 or less in the milk powder samples. For the screening method, the data of the precursor and product ions of the target analytes were simultaneously acquired under the All Ions MS/MS mode in a single run. A homemade library including the elemental composition, retention time, and full-scan product ions was utilized for the confirmation and identification of the target compounds. The applicability of the screening method was verified by applying to real milk powder samples, and certain veterinary drugs were detected in some cases.

Simultaneous Determination of 44 Pesticides in Tobacco by UPLC/MS/MS and a Modified QuEChERS Procedure

A novel, simple, and rapid method for determination of the residues of 44 commonly used pesticides in tobacco was developed based on modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedures. The pesticides were extracted with acetonitrile and purified on a mixed sorbents column of primary secondary amine, C18, and graphitized carbon black. Quantitative determination of all pesticides was performed by ultra-performance LC/MS/MS in the positive or negative ionization mode by a single run due to the fast polarity switching capability of the mass spectrometer. Two precursor-product ion transitions were monitored for each compound in the multiple reaction monitoring mode. Quantification was carried out using matrix-matched standard calibration. The method has been validated by various tobacco cultivars, such as Burley, Oriental, and Virginia from different countries. Recoveries of the proposed method for spiked samples ranged from 71.1 to 109.8%, and RSD values were below 10%. The LOQ values were are all below the guidance residue levels proposed by the Agrochemical Advisory Committee of Cooperation Center for Scientific Research Relative to Tobacco. This method is valuable for measurement of pesticide residues in tobacco for QC and monitoring.

Simultaneous determination of 11 quinolones in hotpot ingredients by dispersive solid-phase extraction and ultra performance liquid chromatography-tandem mass spectrometry

A method for the simultaneous determination of the residues of 11 quinolones in hotpot ingredients by quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and ultra performance liquid chromatography-tandem mass spectrometric method (UPLC-MS/MS) was established. The sample was extracted with acetonitrile (containing 5% formic acid) and followed by stratifying with a salting-out agent. Clean-up of the extracts was processed by C18 and PSA, a modified QuEChERS procedure. The analytes were then separated on a Poroshell 120 EC-C18 column, and finally detected by tandem mass spectrometry in positive ESI mode. The linearity of all the 11 quinolones in the range from 1.0 to 100.0 microg/kg had correlation coefficients greater than 0.998. The limits of detection (LOD) of the method were from 1.8 to 3.1 microg/kg and the limits of quantification (LOQ) were from 6.0 to 10.3 microg/kg. The average recoveries of the 11 quinolones were in the range from 70.1% to 100.3%, with relative standard deviations from 2.42% to 10.88%. The established method is sensitive and of good recoveries. It can be applied as a rapid and reliable method for the determination of the 11 quinolones in hotpot ingredients.