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

Optimization and validation of high-performance liquid chromatography using modified QuEChERS to determine anthelmintic drugs in mutton.

The aim of this study was to rapidly determine the presence of anthelmintic drugs in sheep meat using the optimized high-performance liquid chromatography-ultraviolet (HPLC-UV) method with modified QuEChERS (quick, easy, cheap, effective, rugged, safe) technology. Fifty fresh sheep meat samples from different slaughterhouses were collected. A double extraction procedure (QuEChERS/HPLC-UV technology) was used to extract the target analytes. A multilevel calibration curve from 1 to 1000 g/kg was used to establish instrument linearity for rafoxanide, albendazole, and closantel, whereas 0.1-100 μg/kg was used for ivermectin, levamisole, and oxyclozanide to find the lowest concentration, maximum residue limit (MRL), and occupied range for targeted analytes. The concentration levels were used to investigate the linearity, whereas several certified reference materials were applied to determine accuracy. The process was linear for all combinations, from the limit of quantification (LOQ) to the maximum concentration. The LOQ was established at 0.5μg/kg for ivermectin, levamisole, and oxyclozanide and 10μg/kg for rafoxanide, albendazole, and closantel. Recovery values were 70%-120%, and repeatability/reproducibility stated in relative standard deviation was obtained at less than 20%. QuEChERS method revealed that most meat samples contained anthelmintic drug residues, of which the majority exceeded the MRLs. Thus, the drugs should be used correctly in animals to avoid residues in food for human consumption.

Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry.

Gas chromatography (GC) tandem mass spectrometry (MS/MS) stands as a preeminent analytical instrument extensively employed for the surveillance of pesticide residues in food. Nevertheless, these methods are vulnerable to matrix effects (MEs), which can potentially affect accurate quantification depending on the specific combination of analyte and matrix. Among the various strategies to mitigate MEs, matrix-matched calibration represents the prevailing approach in pesticide residue applications due to its cost-effectiveness and straightforward implementation. In this study, a total of 45 representative pesticides were analyzed in three different varieties of avocado (i.e., Criollo, Hass, and Lorena) using the Quick-Easy-Cheap-Effective-Rugged-Safe (QuEChERS) method with ammonium formate and GC-MS/MS. For this purpose, 5 g of the avocado sample was extracted with 10 mL of acetonitrile, and then 2.5 g of ammonium formate was added to induce phase separation. Subsequently, the supernatant underwent a cleanup process via dispersive solid-phase extraction employing 150 mg of anhydrous MgSO4, 50 mg of primary-secondary amine, 50 mg of octadecylsilane, 10 mg of graphitized carbon black, and 60 mg of a zirconium oxide-based sorbent (Z-Sep+). The GC-MS/MS analysis was successfully performed in less than 25 min. Rigorous validation experiments were carried out to assess the performance of the method. The examination of a matrix-matched calibration curve for each variety of avocado revealed that the ME remained relatively consistent and less than 20% (considered as a soft ME) for most pesticide/variety combinations. Furthermore, the method´s limits of quantification were lower than 5 µg/kg for all three varieties. Finally, the recovery values for most pesticides fell within the acceptable range of 70-120%, with relative standard deviation values below 20%.

Monitoring and method validation of organophosphorus/organochlorine pesticide residues in vegetables and fruits by gas chromatography.

In this study, an analytical method was developed and validated for the assessment of pesticide residues in commonly consumed vegetables and fruits. Fresh samples of apple, green peas, tomatoes, and cucumbers were processed and subjected to analysis using a modified QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction technique. Subsequently, quantification of pesticide residues was conducted utilizing gas chromatography (GC)-electron capture detector. Extraction and cleanup parameters were meticulously optimized, resulting in a modification of the original QuEChERS method. This modification aimed to reduce solvent consumption, making the study more environmentally friendly. The developed method was validated in terms of selectivity, specificity, linearity, precision, and accuracy by following the SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable relative standard deviation (<20.0%). Recovery was assessed at the limit of quantification level and was observed to fall within the range of 70%-120%, with relative standard deviations below 5.45%. The validated method presented here can be applied to analyze pesticide residues in various other vegetables, fruits, and cereals. It is essential for ongoing monitoring of pesticide residues to ensure public safety.

AFB1 colorimetric aptamer sensor for the detection of AFB1 in ten different kinds of miscellaneous beans based on gold nanoparticles and smartphone imaging.

A simple, rapid, low-cost, sensitive, intuitive, visual, label-free, colorimetric smartphone-assisted assay was developed for the measurement of aflatoxin B1 in miscellaneous beans. Ten different kinds of miscellaneous beans were treated and measured by modified QuEChERS(Quick、Easy、Cheap、Effective、Rugged、Safe) method with aflatoxin B1 nucleic acid aptamer as a recognition element and gold nanoparticles as indicators. Several factors influencing its sensitivity were investigated, including consumes and NaCl concentrations, as well as incubation time and specificity. The results showed a good linear relationship between concentrations of 0.2-8.0ng/g under optimal conditions. With a detection limit of 0.08ng/g, the linear regression equation was Y=0.024X+0.4615 (R=0.9989). Sensor specificity is good. The content of aflatoxin B1 in bean samples was determined successfully. The recovery of aflatoxin B1 ranged from 87.18% to 110.24%. The whole thing took 15min. This smartphone-assisted colorimetric aptamer sensor can be used to detect aflatoxin B1 in beans.

Evaluation of the potential migration of acaricides from stamped beeswax to honey simulating beehive conditions: A pilot study

There is an issue concerning the migration of pesticides from stamped beeswax to other bee products, mainly, honey. This implies that honey and other beehive-based products could be contaminated, which would represent a potential risk to consumers and food safety. To determine the degree to which acaricides can be transferred from the stamped beeswax to the honey, a pilot experiment was designed consisting of placing beeswax that contained acaricides (endogenous content, τ-fluvalinate, chlorfenvinphos, and coumaphos; spiked samples, coumaphos) in contact with multifloral honey in an incubator. Temperature and shaking conditions were settled simulating beehive conditions. The isolation of the analytes from beeswax involved the use of a QuEChERS (quick, easy, cheap, effective, rugged & safe) method, and honey was analyzed through a solvent extraction procedure. Acaricides were determined in the resulting extracts by gas chromatography with mass spectrometry detection. Coumaphos was the only acaricide transferred into honey in beeswaxes with endogenous acaricide content; meanwhile, results of the experiments with spiked beeswax samples showed that the initial concentration present in the contaminated beeswax significantly influences the transfer to honey, as it was observed that in the spiked beeswax sheets with high levels of coumaphos, the migration from beeswax to honey arose.

Development of a Modified QuEChERS Method Based on Magnetic Multi-Walled Carbon Nanotubes as a Clean-Up Adsorbent for the Analysis of Heterocyclic Aromatic Amines in Braised Sauce Beef.

Heterocyclic aromatic amines (HAAs) generated during the cooking of meats cause adverse effects on human health. The purpose of the current research was to develop a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method using magnetic multi-walled carbon nanotubes (Fe3O4-MWCNTs) as clean-up adsorbents for the rapid determination of HAAs in braised sauce beef. The significant parameters in extraction and clean-up processes were screened and optimized. Under optimal conditions, the LODs ranged from 3.0 ng/g to 4.2 ng/g. The recoveries (78.5−103.2%) and relative standard deviations RSDs (<4.6%) of five HAAs were obtained. These are in accordance with the validation criteria (recovery in the range of 70−120% with RSD less than 20%). Compared with conventional clean-up adsorbents (PSA or C18), Fe3O4-MWCNTs displayed equivalent or better matrix removal efficiency, while making the pretreatment process easier and more time-saving through magnetic separation. Less usage of adsorbent makes the method possess another advantage of being lower in cost per sample. The method developed was successfully applied to analyze real samples collected from local deli counters, demonstrating Fe3O4-MWCNTs could be considered as an effective alternative adsorbent with great potential in the QuEChERS process.

Rapid and simultaneous extraction of phthalates, polychlorinated biphenyls and polycyclic aromatic hydrocarbons from edible oil for GC–MS determination

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method, for reliable semi-quantitative screening of 27 organic contaminants including phthalates (PAEs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrometry (GC-MS) in edible oil, was developed. N-hexane saturated with acetonitrile and C18-Z-Sep+ was used for extraction and cleanup in liquid liquid extraction-dispersive solid phase extraction (LLE-dSPE) combined with freezing-lipid precipitation. Subsequently, NAGINATA2.0 software with a constructed calibration-locking database was used to detect the organic contaminants and validate the method. The calibration curves were observed to be linear in the range of 0.01–0.5 µg/mL for PAEs and PAHs, and 0.02–1 µg/mL for PCBs. The recoveries for most of the organic contaminants were in range of 70.9–110% with relative standard deviation less than 20%. The proposed method should provide an efficient tool for semi-quantitative screening of numerous organic contaminants in edible oil samples simultaneously.

An integrative review on the analysis of pesticide multiresidues in sweet pepper samples using the QuEChERS method and chromatographic techniques

Since foods are complex matrices that contain pesticides of different classes, multiresidue sample preparation methods such as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) are used and modified to obtain more accurate and sensitive results. This work was developed through an integrative review in the journal databases Capes, Science Direct, Scielo, and Scientia Chromatographic, from 2011 to 2021, to answer the following question: “What is the most efficient and advantageous sample preparation method for the determination of multiresidue pesticides of interest in sweet pepper samples, when chromatographic techniques are used for detection?” The sweet pepper was chosen because the Pesticide Residue Analysis in Food Program (PARA) suggests that it is the sample with the highest percentage of irregularities related to active ingredients not allowed or above the Maximum Residue Limit (MRL). A total of 391 articles were found, 11 of which met the inclusion criteria established. Several analyses were studied. The organophosphates were the most studied class of pesticide, with seven articles. In addition, there was a predominance of nonpolar analytes (log Kow &gt; 1). The use of different extracting solvents, such as methanol, acetonitrile, ethyl acetate, and acetone, was observed, with acetonitrile presenting the best analytical parameters in most cases. The use of different sorbents such as secondary and primary secondary amine (PSA), ocatadecyllane (C18), graphite carbon (GCB), and carbon black was noted, as well. The authors highlight the difficulties in the analysis when the matrix effect is significant (except for fensulfothion, tensulfothion, flonicamid, and its metabolite TFNA-AM) and the degradation of analytes through the analysis process (flonicamid, captan, folpet, thiophanate methyl and benomyl). Finally, the statistical test Analysis of Variance (ANOVA) was used to identify if there was a significant difference between the different methods used for the same analysis or when the same method used for the different analytes.

Simultaneous Determination and Health Risk Assessment of Four High Detection Rate Pesticide Residues in Pu’er Tea from Yunnan, China

Four pesticides with a high detection rate in Pu’er tea have been determined by a QuEChERS (quick, easy, cheap, effective, rugged, safe) method with multiwalled carbon nanotubes (MWCNTs), and combined ultrahigh-performance liquid chromatography–triple quadrupole linear ion trap-tandem mass spectrometry (UHPLC-QTRAP-MS/MS). MWCNs have been compared with other common purification materials, and found to be superior. The matrix effect was systematically studied, and the results show that the MWCNs can quickly and effectively reduce matrix interference values, which were in the range from −17.8 to 13.8. The coefficients (R2) were greater than 0.99, with the limit of quantification ranging from 0.1 to 0.5 μg/kg, and the recovery rate ranging from 74.8% to 105.0%, while the relative standard deviation (RSD) ranged from 3.9% to 6.6%. A total of 300 samples, taken from three areas in which Yunnan Pu’er tea was most commonly produced, tested for four pesticides. The results show that the detection rate of tolfenpyrad in Pu’er tea was 35.7%, which is higher than other pesticides, and the lowest was indoxacarb, with 5.2%. The residual concentrations of chlorpyrifos, triazophos, tolfenpyrad and indoxacarb ranged from 1.10 to 5.28, 0.014 to 0.103, 1.02 to 51.8, and 1.07 to 4.89 mg/kg, respectively. By comparing with China’s pesticide residue limits in tea (GB 2763-2021), the over standard rates of chlorpyrifos, tolfenpyrad, and indoxacarb were 4.35%, 0.87% and 0%, respectively. The risk assessment result obtained with the hazard quotient (HQ) method shows that the HQ of the four pesticides was far less than one, indicating that the risk is considered acceptable for the four pesticides in Pu’er tea. The largest HQ was found for tolfenpyrad, 0.0135, and the smallest was found for indoxacarb, 0.000757, but more attention should be paid to tolfenpyrad in daily diets in the future, because its detection rate, and residual and residual median were all relatively high.

Determination of bongkrekic acid in tremella and auricularia auricular by improved QuEChERS method combined with ultra-high performance liquid chromatography-triple quadrupole mass spectrometry

采用改良的QuEChERS方法,结合超高效液相色谱-串联质谱(UHPLC-MS/MS)建立了银耳和木耳中米酵菌酸含量测定的分析方法。对QuEChERS方法的提取、净化条件进行了优化,发现提取液中乙酸含量对米酵菌酸的提取效率影响很大,最终采用5%(v/v)乙酸乙腈为提取溶剂,盐析分层,再用200 mg C18分散固相萃取净化。对UHPLC-MS/MS分析条件也进行了优化,以含0.01%(v/v)甲酸、0.05%(v/v)氨水的水溶液和甲醇为流动相,在Waters HSS T3柱(100 mm×2.1 mm, 1.8 μm)上分离,以电喷雾电离、多反应监测负离子模式进行检测。在优化好的条件下,银耳和木耳中米酵菌酸检测的基质效应分别为-6.3%和-11.5%,表明该方法具有很好的净化效果,样品基质不会对米酵菌酸的检测产生影响。进一步对方法学进行了考察,在1~200 μg/L范围内,线性方程回归系数的平方(R2)大于0.999,以信噪比的3倍和10倍计算的方法检出限和定量限分别为0.15 μg/kg和0.5 μg/kg。银耳中3种添加水平0.5、10、50 μg/kg下的加标回收率为92.4%~102.6%,日内和日间相对标准偏差(RSD)分别为4.3%~4.9%和3.2%~3.5%;木耳的加标回收率为89.6%~102.3%,日内和日间RSD分别为2.4%~9.5%和3.6%~4.1%,表明该方法具有很好的准确度和精密度。最后,将该方法应用于实际样品中米酵菌酸的分析,取得了很好的效果。该工作为银耳和木耳中米酵菌酸的风险防控提供了一种有效的检测技术。

A fluorinated chitosan-based QuEChERS method for simultaneous determination of 20 organophosphorus pesticide residues in ginseng using GC-MS/MS.

In this study, a new fluorinated methacrylamide (MACF) was synthesized and evaluated as an adsorbent in the dispersive solid-phase extraction for the effective determination and extraction of 20 organophosphorus pesticides (OPPs) from ginseng samples using the QuEChERS (quick, easy, cheap, effective, rugged, safe) method coupled with GC-MS/MS. The properties of MACF were characterized using Fourier-transform infrared spectroscopy, elemental analysis, and high-resolution 19 F NMR. MACF, chitosan, primary and secondary amine, octadecylsilane, graphitized carbon black, Z-Sep, Z-Sep+ , and EMR-Lipid were compared in terms of extraction efficiency. The best results were obtained when MACF was used. Matrix-matched calibration was employed for quantification. All the OPPs exhibited good linearity (r2 > 0.9969) with the concentration at their respective concentration ranges. The limits of detection were 1.5-3.0μg/kg, and the limits of quantification were 5.0-10.0μg/kg. The trueness of the 20 pesticides at four spiked levels ranged from 86.1 to 111.1%, and the relative standard deviation was less than 11.3%. The modified QuEChERS method using MACF as the adsorbent was sensitive, reliable, and cost-effective and could be used for the determination of 20 OPP residues in ginseng.

Determination of Pydiflumetofen Residues in Rice and its Environment by an Optimized QuEChERS Method Coupled with HPLC-MS.

Pydiflumetofen is a new succinate dehydrogenase inhibitor fungicide, and the method for determination of its residues in rice and associated environmental samples has not yet been reported. Here, we optimized, Quick Easy, Cheap, Effective, Rugged, Safe (QuEChERS) method for sample preparation, and used high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) to detect the residual amounts of pydiflumetofen in rice and its environment. The results showed that there was a good linearity over the pydiflumetofen concentration range of 0.01-0.1mg/L in all matrices (R2 > 0.99). At the spiked levels of 0.01, 0.05, and 0.1mg/kg, the recovery rates of pydiflumetofen from various matrices were between 84.23 and 105.10 %, with the relative standard deviation of 1.07-9.99 %. The limit of detection (signal-to-noise ratio = 3) of the proposed method for pydiflumetofen was in the range of 1.9-3.5µg/kg, and the limit of quantification (signal-to-noise ratio = 10) was in the range of 6.3-11.7µg/kg.

Estimation of Pesticide Residues in Selected Products of Plant Origin from Poland with the Use of the HPLC-MS/MS Technique

The purpose of this work was to compare the content of pesticide residues (250) in unprocessed plant products from farms situated in the eastern part of Poland. The content of pesticide residues in the analysed samples was assayed with the use of the QuEChERS (Quick Easy Cheap Effective Rugged Safe) method combined with HPLC-MS/MS (high performance liquid chromatography with tandem mass spectrometry) analysis. The analyses revealed that among 160 analysed samples, pesticide residues were detected in 83 samples (approximately 52%), while in 77 samples (approximately 48%), no presence of those substances was noted. In all the samples in which the presence of the sought compounds was identified, their levels did not exceed the Maximum Residue Levels (MRL). The most often identified ones were azoxystrobin—detected in 36 samples (22.5%), linuron—assayed in 33 samples (20.6%), chlorpyrifos and carbendazim—each detected in 13 samples (8.1%), metalaxyl and metalaxyl M—in 11 samples (6.9%), and acetamiprid—in 7 samples (4.4%).

Enantioselective effects of the chiral fungicide tetraconazole in wheat: Fungicidal activity and degradation behavior

Tetraconazole, a chiral triazole fungicide, is widely used for the prevention of plant disease in wheat fields. However, the chirality of pesticides like tetraconazole can cause diverse biological responses. Therefore, it is important that research is conducted to investigate the enantioselective effects of chiral enantiomers in this regard. The absolute configurations of two tetraconazole enantiomers were initially confirmed by ECD (Electrostatic circular dichroism). The bioassay test showed that the fungicidal activity of (R)-(+)-tetraconazole against two pathogens (R. cerealis and F. graminearum) was approximately 1.49–1.98 times greater than that for (S)-(−)- tetraconazole. Following recovery experiments, a modified QuEchERS (Quick, easy, cheap, effective, rugged, safe) method was established using UPLC-MS/MS (ultra-performance liquid chromatography tandem mass spectrometry). The mean recoveries from plant and soil sample ranged from 78.9% to 100.5% with intraday relative standard (RSDr) values of 0.8%–6.9% and interday relative standard (RSDR) values of 3.0%–5.2% respectively. The stereoselective degradation of tetraconazole in wheat meant that (S)-(−)-tetraconazole was more rapidly degraded than (R)-(+)-tetraconazole. Conversely, (R)-(+)-tetraconazole was preferentially degraded in wheat soil. These results will provide us with a greater understanding when assessing future environmental risk assessments and strategies that invoke pesticide reduction.

Distribution and degradation kinetics of cyhalodiamide in Chinese rice field environment

Abstract Cyhalodiamide is a novel agrochemical which is effective against Lepidoptera pests, including Cnaphalocrocis medinalis, Chilo suppressalis, Pieris rapae, Plutella xylostella, Helicoverpa armigera, etc. In the study, a fast and accurate analytical method was developed to detect cyhalodiamide in Chinese typical rice field environment by a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method with UPLC-MS/MS (ultra-high performance chromatography-tandem mass spectrometry). The mean recoveries of cyhalodiamide varied from 73.5% to 107.5%, with the RSDs from 1.2% to 10.7%. The limits of determination (LODs) were 0.0005 mg·kg− 1, and the limits of quantitation (LOQs) were from 0.002 to 0.01 mg·kg− 1 in all five matrices. This method was used to determine cyhalodiamide residues for studies of the distribution and degradation kinetics in rice field environment. The field trials results showed that cyhalodiamide was easily degradable and the half-lives were 4.2–13.6 d in rice straw, 8.77 d in paddy soil and 5.37–8.45 d in paddy water, respectively. The final residues of cyhalodiamide in brown rice were below 0.35 mg·kg− 1. The used dosage of 33.75 g·hm− 2 with pre-harvest interval (PHI) of 21 d and the maximum residue limit (MRL) of cyhalodiamide in rice at 0.1 mg·kg− 1 were recommended, which would be safe to human health and environment. The developed analytical method will be useful to monitor cyhalodiamide residues and safety evaluation in rice environment.

Multiresidue Analysis of 113 Pesticides in Different Maturity Levels of Mangoes Using an Optimized QuEChERS Method with GC-MS/MS and UHPLC-MS/MS

In this study, a simple and high-throughput multiresidue pesticide analysis method based on the quick, easy, cheap, effective, rugged, safe (QuEChERS) extraction combined with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) is presented for the determination of 113 pesticides in green and ripe mangoes. Different buffer systems and purification sorbents were optimized to get better recovery. Extracts from mangoes after acid acetonitrile and ammonium acetate extraction were directly injected to UHPLC-MS/MS analysis, whereas other GC-amenable compounds were treated with cleanup approaches with a mixture of sorbents [400 mg primary-secondary amine (PSA) and 400 mg graphitized carbon black (GCB)] for GC-MS/MS analysis. Recoveries for the majority of pesticides at spike levels of 10, 50, and 100 μg/kg were ranged between 70 and 120% with RSD values below 20%. Limits of detection (LODs) were below 4 μg/kg, whereas limits of quantification (LOQs) were below 10 μg/kg. Response linearity was good in the range between 5 and 500 μg/kg. The matrix effect for 56 pesticides by GC-MS/MS analysis exhibited a non-significant matrix effect (≤ 25%) in green and ripe mangoes. For 57 pesticides used for UHPLC-MS/MS analysis, the optimized method in green mango provided no significant matrix effect (≤ 25%) for 63% of the compounds, whereas only for 16 and 21% compounds, the matrix effect was medium (25–40%) and strong (> 40%); the optimized method in ripe mango provided no significant matrix effect (≤ 25%) for 61% of the compounds, whereas only for 26 and 12% compounds, the matrix effect was medium (25–40%) and strong (> 40%). Following the application of a “top-down” approach, the expanded measurement uncertainty was both 21% on average (coverage factor k = 2, confidence level 95%) in green and ripe mangoes. The application of GC-MS/MS and UHPLC-MS/MS coupled with the modified QuEChERS extraction procedures was proved to adequately quantitate these pesticides in different maturity levels of mangoes.

Simultaneous Determination of 19 Plant Growth Regulator Residues in Plant-originated Foods by QuEChERS and Stable Isotope Dilution-Ultra Performance Liquid Chromatography-Mass Spectrometry.

In this study, a highly sensitive and fast method of QuEChERS (acronym of quick, easy, cheap, effective, rugged, safe) combined with isotope dilution-ultra performance liquid chromatography coupled to tandem mass spectrometry was developed for the simultaneous determination of 19 plant growth regulators in plant-originated foods. The samples were initially extracted with acetonitrile containing 1% acetic acid and then the QuEChERS method was applied after the pH value was adjusted to 5.5 - 6.0, using 3-indolepropionic-d2 acid and forchlorfenuron-d5 as internal standard. The targeted 19 plant growth regulators were separated on an HSS T3 column using acetonitrile: 5 mmol/L ammonium acetate as the mobile phase. Quantitative results were based on multiple reaction monitoring mode after ionization in positive and negative electrospray ionization mode. Good linearity was achieved within a wide range and all the correlation coefficients were greater than 0.997. The limit of quantification was 0.060 - 6.0 μg/kg. Rate of recovery and relative standard deviation were 72.3 - 115.8 and 1.78 - 5.32%, respectively. The method was successfully applied to measure 19 plant growth regulator residues in 280 plant-originated commercial foods collected from local supermarkets in China. Twelve plant growth regulators were found in some of the analyzed samples.

Fast and easy liquid chromatography–mass spectrometry method for evaluation of postharvest fruit safety by determination of mycotoxins: Fumitremorgin C and verruculogen

Fumitremorgin C and verruculogen are mycotoxins produced by heat-resistant Neosartorya fischeri. Easy and fast monitoring of their production by selective and sensitive analytical methods is crucial for ensuring postharvest quality of fruit, food safety, and thus human health and well-being. A six-minute liquid chromatography tandem mass spectrometry method (LC/MS/MS) was developed for quantification of fumitremorgin C and verruculogen in potato dextrose broth (PDB), strawberry juice, strawberry fruit, and soil. Mycotoxins were extracted from all media with the QuEChERS (Quick Easy Cheap Effective Rugged Safe) method. The lower limit of quantification (LLOQ) of the method for both mycotoxins was 1μgL−1 for PDB and strawberry juice and 1μgkg−1 for strawberry fruit and soil. Collision-induced dissociation of protonated fumitremorgin C and verruculogen ions was also examined by high-resolution mass spectrometry to assist researchers in non-targeted screening for mycotoxins and in identification of these two toxins. The developed LC/MS/MS method was applied to examine mycotoxin production by 45 environmental Neosartorya strains: 5 well-known strains, included in the study as reference strains, and 40 strains that were newly isolated and identified by us.

Multiresidue Pesticide Analysis Using QuEChERS Method in Vegetable Samples by Ultra-Performance Liquid Chromatography

A multi-residue Ultra Performance Liquid Chromatography (UPLC) method has been developed and validated for the determination and quantification of 30 pesticide residues in vegetable. Samples were prepared by QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method using acetonitrile as a solvent. And an additional clean up step of PSA and GCB is used. The composition of mobile phase was optimized to get good peak resolution and sensitivity. The developed method showed an average spiked recoveries of more than 80.0% and 105.0%. The method was applied to determine the pesticide residues in cauliflower, cabbage, onion, potato, chilli, bendi, brinjal and tomato samples. Trace amounts of acephate and cabaryl were found in chilli and potato samples respectively.

Simultaneous determination of anabolic steroids and β-agonists in milk by QuEChERS and ultra high performance liquid chromatography tandem mass spectrometry.

A simple, accurate and highly sensitive multiresidues method was developed for the determination of 9 anabolic steroids and 16 β-agonists in milk. Target compounds were extracted and separated by a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method with Primary secondary amine (PSA) and Zinc oxide (ZnO) nanoparticles as adsorbents. The analytes were determined by ultra high performance liquid chromatography coupled to an electro-spray ionization tandem mass spectrometer (UHPLC-MS/MS) operating in negative/positive multiple reaction monitoring mode. The effect of QuEChERS including organic solvent, amount of ZnO nanoparticle was evaluated. Good linearity was obtained for the analytes in the concentration range of 0.1-200μg/L with a correlation coefficients higher than 0.994. Decision limits (CCα) was from 0.007μg/kg-0.1μg/kg, and detection capabilities (CCβ) was in the range of 0.02-0.4μg/kg. The recoveries of these compounds were between 63% and 126% at three fortified levels. Reproducibility represented by RSD was with 10% or less. The method was successfully applied to screening of real milk samples obtained from local markets and confirmation of the suspected target analytes.