A Modified QuEChERS Sample Preparation Method for the Analysis of 70 Pesticide Residues in Tea Using Gas Chromatography-Tandem Mass Spectrometry

A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the simultaneous determination of 70 pesticides in tea was developed using gas chromatography-tandem mass spectrometry. Prior to acetonitrile extraction of the target compounds from tea matrix, samples were soaked in distilled water to improve the extraction efficiency. A mixture of adsorbents containing primary–secondary amine, octadecylsilane, graphite carbon black, and multiwalled carbon nanotubes was applied for the cleanup. Additional steps of concentration and solvent exchange were performed to reduce the amount of co-extracts and to decrease the limit of detection of the method. For all pesticides, good linear calibrations with coefficients (R ²) ≥0.99 were obtained at the concentration levels of 10, or 50 to 1,000 μg ml^?1. The limits of quantifications (LOQs) were 5–25 μg ml^?1, respectively. The recovery rates of samples spiked with 20, 100, and 200 μg kg^?1 of analytes ranged from 71 % to 105 %. In addition, the relative standard deviations were lower than 20 %. A total of 331 tea samples were analyzed using this method, and the levels of five pesticide residues in nine tea samples exceeded the strictest maximum residual limits (MRLs).     

普洱茶中有机磷类农药残留的测定

为建立气相色谱技术同时测定茶叶中多种有机磷农药残留的方法,并用该方法检测来自云南省5 个普洱茶主产区的30 个普洱茶样品中的有机磷农药残留量,为其安全性评价提供科学数据。样品以乙酸乙酯为提取剂经超声波萃取,提取液用活性炭小柱净化,采用气相色谱火焰光度检测器检测,外标法定量。该方法在3 个添加水平下,9 种组分的平均回收率为71.1%～113.8%,相对标准偏差为0.9%～13.3%。方法的检测限为1.0～2.5μg/kg。普洱茶样品检出的农药有敌敌畏、乙酰甲胺磷、乐果、杀螟硫磷、马拉硫磷、喹硫磷、三唑磷,其中杀螟硫磷和乐果的检出率较高,但含量均低于欧盟限量标准。从茶叶中有机磷农药残留量来看,普洱茶具有较高的食用安全性。     

Pesticide residues and estrogenic activity in fruit and vegetables sampled from major fresh produce markets in South Africa

Food is likely to be one of the major pathways through which people are exposed to endocrine-disrupting chemicals. With the exception of residual effects, there are concerns that a number of naturally occurring and synthetic chemicals exert adverse effects upon endocrine systems in wildlife and humans. The current study reports selected pesticide concentrations and the total estrogenic activity of fruit and vegetables using the recombinant yeast oestrogen screen (YES) and T47D-KBluc reporter gene assays. A total of 53 food samples (27 fruit and 26 vegetables) from Johannesburg and Tshwane fresh produce markets (in South Africa) were analysed. Of these, 17 contained one to three different pesticide residues with concentrations ranging between 0.01 and 0.68 mg kg^–1, whereas in the rest of the samples no residues were detected. All pesticides detected except in one sample were below the maximum residue level (MRL), but others were unauthorised for use in specified fruit and vegetables. Estrogenic activity was detected in 26.4% (14 samples) of the samples tested, and the estradiol equivalents ranged from 0.007 to 2 pg g^–1. Although the estrogenic activity was low, it may contribute to adverse health effects. Continuous monitoring for pesticides in fruit and vegetables is important in view of the unauthorised pesticides detected in produce from South Africa and the endocrine-disrupting chemical activity found.     

Occurrence of pesticide residues and transformation products in different types of dietary supplements

The purpose of this study was to evaluate the presence of pesticide residues and transformation products in dietary supplement products. Thirty-two samples were analysed to determine 177 pesticides by gas chromatography–tandem mass spectrometry (GC-MS/MS) and 333 pesticides by liquid chromatography–high-resolution mass spectrometry (LC-HRMS). Pesticides were extracted from different kinds of dietary supplements by the use of a modified QuEChERS extraction method. Six samples contained pesticide residues at concentration up to 92.7 µg kg^?1, but only butralin exceeded the maximum residue limits set for raw material. In addition to target compounds, LC-HRMS enables the simultaneous detection of non-target pesticides. In this case, transformation products of pesticides were detected in the analysed samples using HRMS analyser (Exactive-Orbitrap). These compounds were not included in the original method, and they were monitored as post-target compounds, knowing their molecular formula and exact mass. Mass accuracy was always < 2 ppm, corresponding to a maximum mass error. The positive findings endorse the idea that a deeper and continuous investigation of pesticide residues and transformation products in dietary supplement products is necessary in order to guaranty consumer’s safety.     

市售茶叶中30种农药残留与风险评估

本次研究主要为了解30种农药在茶叶中残留状况并对检测结果进行风险评估。随机采购茶叶390份,参考GB 2763-2016对30种农药进行检测,并采用@riskv7.6风险评估软件对检测值进行拟合处理,同时结合点评估和@risk概率评估法评价其膳食暴露风险。结果表明390份茶叶中,农药中检出率最高的为联苯菊酯,高达39.2%。关于样本茶叶中多种农药联用的问题,48%的样品中未检出农药残留。其中203份茶叶中存在农药残留,114份样品中存在2种及以上农药残留情况。所有农药残留水平的95%拟合位点值均能满足GB 2763-2016要求,但有3种不能满足欧盟标准要求。只有一个茶叶的草甘膦检测值超出了GB 2763-2016要求。所检茶叶样品风险评估水平均处在可接受的水平,但甲氰菊酯的急性风险熵处于较高水平。     

Multi-residual Pesticide Monitoring in Commercial Chinese Herbal Medicines by Gas Chromatography–Triple Quadrupole Tandem Mass Spectrometry

To investigate multi-residual pesticide monitoring data in commercial Chinese herbal medicines on major markets, an easy, rapid, and selective gas chromatography with mass spectrometry (GC/MS/MS) method was established for simultaneously determining multi-residual pesticides including organochlorine, pyrethroid, carbamate, and organophosphorus pesticides in Chinese herbal medicines. The analytical method was based on an efficient extraction procedure and further cleanup steps by solid-phase extraction columns, yielding recovery rates in the range of 70.0–120.0 % for the majority of pesticides, except for hexachlorobenze, diazinon, β-HCH, δ-HCH, and omethoate, with precision values expressed as relative standard deviation of 0.1–14.7 %. The limits of detection of the established GC/MS/MS method for all investigated pesticides ranged from 0.01 to 3.6 μg kg^?1 and limits of quantification from 0.03 to 11.88 μg kg^?1. With this validated method, multi-residual pesticides of 132 Chinese herbal medicine samples were analyzed. The monitoring results indicated that pesticide residue was found in 74 samples. In total, 51 pesticides were found with detection rate ranging from 0.76 to 18.94 %. An 82.3 % of positive pesticides were found in less than 6 % of samples. Hexachlorobenzene was found in 25 samples, quintozene in 15 samples, and acephate and simazine in 13 samples. Concentrations of pesticide residue from monitoring data obtained ranged from 0.5 to 203.5 μg kg^?1. The simple and rapid method can be used as routine analysis method in multi-residual pesticide monitoring of Chinese herbal medicines.     

Evaluation of the QuEChERS Method with GC-MS Detection for the Determination of Organochlorine Pesticides in Food of Animal Origin

This paper reports the evaluation of the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the determination of organochlorine pesticide residues in food of animal origin with gas chromatography–mass spectrometry detection. There is a very little information about sample preparation method for the determination of pesticide residues in food of animal origin in the literature. Moreover, any example of application of the QuEChERS method for the determination of pesticide residues in food of animal origin has not been reported as yet. The results showed that the best recovery ratios from 75 to 112 % were obtained for the method with primary secondary amine, C₁₈ sorbents and evaporation to dryness and dissolving the residues in hexane with relative standard deviation lower than 10 % for most compounds. The limit of quantification ranged from 0.0015 to 0.0071 mg kg^?1. This method was also used for the determination of pesticide residues in 15 samples of pork ham. In 12 samples, low concentrations of DDT or its metabolites and isomers of hexachlorocyclohexane were detected. Heptachlor epoxide and α-chlordane were determined in one sample and HCB in two samples. There were no exceedances of maximum residue levels (MRLs) for the determined pesticides in any of the analysed samples.     

Rapid Determination of Organonitrogen, Organophosphorus and Carbamate Pesticides in Tea by Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry (UPLC-MS/MS)

A rapid and effective multiresidue method has been developed for the determination of 18 pesticide residues (selected from organonitrogen, organophosphorus, and carbamate pesticides) in tea by ultrahigh-performance liquid chromatography–tandem mass spectrometry. Tea samples were extracted with acetonitrile and purified by a novel multilayer solid-phase extraction cartridge—Cleanet TPT. Evaluation of the influence of the mobile phase on the ionization efficiency, resolution, and sensitivity was carried out by comparing the acetonitrile–water and methanol–water with different modifiers. The recoveries of all the pesticides varied from 70 to 110 % with a relative standard deviation of less than 15 %, and the determination coefficient for each pesticide was R ²?>?0.99. Matrix-matched standard calibration curve was used to reduce errors associated with matrix-induced enhancement or suppression effects. The limit of detection for all targeted pesticides ranged from 0.03 to 1.5 μg/kg. Applicability of this analytical approach was confirmed by successful determination of tea samples from different regions of China.     

烟台市售茶叶中12种农药残留的监测及其健康风险评价

目的了解烟台市售茶叶农药残留污染水平,评价其膳食暴露健康风险,以期为生产监管和消费提供依据。方法采用简单随机抽样的方法,采集在售茶叶样本176份,按照《2016年国家食品污染和有害因素风险监测工作手册》规定的标准操作程序进行12种农药检测,运用危害指数(hazard index,HI)法评价其膳食暴露风险。结果 176件样品中,97件检出农药残留,烟台市售茶叶中农药残留检出率为59.09%,红茶、绿茶、袋泡茶的检出率分别为54.72%、58.90%、73.33%。检出的11种农药中,联苯菊酯检出频次最多,数值范围0.01~2.25 mg/kg,均值为0.133 mg/kg,乌龙茶中残留均值最大,为0.27 mg/kg;其次为绿茶、红茶、袋泡茶和桑叶茶。红茶、绿茶、袋泡茶、乌龙茶、桑叶茶的HI分别为0.0051、0.0066、0.0025、0.0020、0.0019、0.0036,均远小于1,其危害指数处在可接受的安全水平。结论烟台市售茶叶中农药残留检出率较高,但农药残留值低于GB 2763-2016《食品安全国家标准食品中农药最大残留限量》的限量值。茶叶中残留农药HI值远远小于1,处在安全的健康风险水平。     

唐山地区韭菜农药残留检测分析及膳食摄入风险评估

为了解唐山地区流通韭菜的农药残留状况与民众的膳食摄入风险,该研究采用高效液相色谱-串联质谱仪(HPLC-MS/MS)和气相色谱仪(GC)对2020年在唐山地区采集的415个韭菜样品分别进行了68种农药残留定性定量检测,并对韭菜样品中检出的农药进行风险评估.结果 表明,415个韭菜样品共计检出41种农药残留,检出率为69...     

Tracking residual organochlorine pesticides (OCPs) in green,herbal, and black tea leaves and infusions of commercially available tea products marketed in Poland

The content of residual organochlorine pesticides (OCPs) was examined in green, herbal, and black tea leaves as well as in their infusions prepared from tea products marketed in the main supermarkets in Poland. It was found that the detected mean levels of organochlorine residues in tea leaves ranged from ?1 dry weight. Among hexachlorocyclohexane isomers, γ-HCH in green tea occurred in the highest concentrations. Among dichlorodiphenyltrichloroethane (DDT) metabolites the highest level of p,p′DDT (1.96 ng g^?1 dw) was in green tea samples. The transfer of OCPs from tea leaves to brew was investigated. The present study revealed that during the infusion process, a significant percentage of the residues, particularly pesticides with high water solubility, were transferred to the infusions. The obtained results show that the percentage transfer of each pesticides from tea to the tea infusions ranged from 6.74% (heptachlor) to 86.6% (endrin). The detected residues were below current MRLs for these pesticides.     

Assessment of pesticide residues in fresh peach samples produced under integrated crop management in an agricultural region of northern Greece

A multi-residue method using selected ion monitoring mode GC/MS has been developed for the quantitative analysis of residue levels of 23 widely used pesticides in fresh peaches produced under integrated crop management process (ICM). The proposed methodology involved a sample extraction procedure using liquid–liquid partition with acetonitrile followed by a clean-up step based on solid-phase extraction (SPE). Fortification studies were performed at different concentration levels for various types of peaches that differ in properties, such as appearance, flavor and pit. The data showed that the different peach matrices had no significant effect on recoveries. Recoveries were greater than 80% for most of the pesticides with a RSD below 18%. The limits of quantification (LOQs) were in the range 0.002–0.050 mg kg^?1, depending on the compound. To assess method performance with real samples and determine whether pesticide concentrations in peaches exceed their maximum residue levels (MRLs), the proposed method was successfully applied to the analysis of 104 fruit samples collected under integrated pest management (IPM) production during the 2006 cultivation period. Residues detected were lower than those established by legislation for all pesticides, except diazinon, where one positive sample was detected at a level of 0.03 mg kg^?1.     

Evaluation of pesticide residues in fruits and vegetables from Algeria

ABSTRACT

A total of 160 samples of 13 types of fresh fruits and vegetables from domestic production and import were analysed to detect the presence of pesticide residues. Analysis was performed by multi-residual extraction followed by gas chromatography–mass spectrometry. In 42.5% of the tested samples, no residues were found and 12.5% of samples contained pesticide residues above maximum residue limits. Risk assessment for long-term exposure was done for all pesticides detected in this study. Except chlorpyrifos and lambda-cyhalothrin, exposure to pesticides from vegetables and fruits was below 1% of the acceptable daily intake. Short-term exposure assessment revealed that in seven pesticide/commodity combinations, including three pesticides (chlorpyrifos, deltamethrin and lambda-cyhalothrin), the acute reference dose had been exceeded.     

Method Development,Optimization and Validation of Matrix Hydration Effect on Pesticide Residues in Cocoa Beans Using Modified QuEChERS Method and Gas Chromatography Tandem Mass Spectrometry

Modified QuEChERS method combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed and validated to determine pesticide residues in dried cocoa beans. Extraction efficiency of matrix hydration effect on 19 pesticide residues was studied and optimized using 2³ full factorial design with percentage recoveries as the response variable. The optimized hydration method was validated for 24 pesticides, and recoveries obtained were in the range of 70–120% with relative standard deviations of less than 20% for most pesticides. Limit of quantification was obtained at 10 μg/kg for all pesticides, and this value was lower than national maximum residue levels (MRLs). Finally, the developed and optimized method was applied to real cocoa bean samples and the results from incurred residues were compared between method with and without matrix hydration. These results suggest that the addition of water to the dry and high-fat cocoa bean samples is crucial in pesticide residue analysis.     

Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia

Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. This paper presents the results of pesticide monitoring of 47 samples of wine grapes (Vitis vinifera L.) from the 2006 vintage from vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them 20 were allowed in IPM in 2006. Grapes were sampled at harvest. Two internal analytical methods were used for the determination of pesticides: gas chromatography-mass spectrometry (GC-MS) method for the determination of dithiocarbamates and a multi-residue GC-MS method. One grape sample (2.1%) contained no residues or they were below the limit of detection, 28 samples (59.6%) contained residues lower or equal than maximum residue levels (MRLs), and 18 samples (38.3%) exceeded national MRLs for cyprodinil (the concentration range was 0.03–0.40 mg kg^?1 of cyprodinil) and fludioxonil (concentration was 0.03 mg kg^?1 of fludioxonil). Multiple residues were found in 41 samples (87.2%). The highest number of pesticides detected per sample was seven. No violation of pesticides allowed in IPM was observed. Folpet (97.9%), cyprodinil (51.1%), dithiocarbamates (44.7%), chlorothalonil (23.4%), chlorpyriphos (19.1%) and pyrimethanil (14.9%) were the most frequently found pesticides in grapes. Risk assessment showed that the exceeded concentrations of cyprodinil and fludioxonil did not represent any risk for consumer's health (the national estimate of short-term intake as a percentage of the acceptable daily intake was below 100%).     

普洱茶对小鼠血糖的干预作用

将昆明种雄性小鼠随机分为5 组, 每组8 只, 分别为阴性对照组、阳性对照组和普洱茶低（0.45 g/（kg·d））、中（0.90 g/（kg·d））、高（1.35 g/（kg·d））剂量组。每天灌胃给药,测体质量,连续处理30 d后,禁食24 h,取血测血糖、胰岛素、α-葡萄糖苷酶活力,以研究普洱茶对小鼠血糖的干预作用。结果显示：普洱茶能显著降低小鼠的体质量、脂肪系数、血糖、胰岛素和α-葡萄糖苷酶活力。与阳性对照组比较,普洱茶低、中、高剂量处理组小鼠的血糖分别降低为16.86%、29.64%、49.58%;胰岛素依次降低为17.17%、32.32%、47.47%;α-葡萄糖苷酶活力分别降低了8.86%、17.86%、32.43%。因此,普洱茶具有减肥降脂作用,同时降低血清中的胰岛素、α-葡萄糖苷酶活力水平,有效改善胰岛素抵抗作用,可作为预防治疗糖尿病和高糖症的潜在保健饮品。     

信阳茶叶农药残留检测及其风险评估

目的 了解信阳地区茶叶农药残留情况及其风险程度,以期为信阳地区茶叶质量安全监测提供依据。方法 2013-2020年8年来连续收集信阳地区茶叶样品132个,依据收集年份GB2763对茶叶中农药残留规定,在同一年按照国家标准、农业行业标准等规定的农药测定方法进行测定。运用危害物风险系数法进行农残风险评估。结果 在132个信阳茶叶样品中,检测出农药残留样品100个,农残检出率为75.76%,共检测到农药种类19种,农残超标率为0。通过危害物风险系数评估显示,噻虫啉、唑虫酰胺、呋虫胺存在高度风险。结论 信阳茶叶农药残留检出率较高,但其含量均在均在国家标准所规定的限量值内,整体处于安全水平。从出现后一直存在的6种农药噻虫嗪、丁醚脲、联苯菊酯、氯氟氰菊酯和高效氯氟氰菊酯、氯氰菊酯和高效氯氰菊酯、啶虫脒以及3种存在高度风险的噻虫啉、唑虫酰胺、呋虫胺的需要重点监测。     

气相色谱-质谱联用法测定茶叶中21种农药残留

该实验建立了茶叶中21种农药残留的气相色谱-质谱（GC-MS）多反应监测模式（MRM）定性、定量分析检测方法,探讨不同 提取方法、提取溶剂、浓缩方式等试验因素对茶叶农药多残留测定结果的影响。 结果表明,以正己烷-丙酮（1∶1,V/V）混合溶剂超声提 取、氮吹浓缩,用气相色谱-质谱法对茶叶样品中21种农药进行定性定量检测,21种农药在0.05～1.00 μg/mL范围内呈良好的线性 关系,相关系数（R2）为0.998 0～0.999 9。 在茶叶样品中分别添加质量浓度0.05 mg/kg、0.20 mg/kg、0.40 mg/kg的农药组分,平均回收率 为83.46%～92.13%,相对标准偏差（RSD）为4.88%～8.51%,检出限为0.002 7～0.021 9 mg/kg,该方法具有前处理简便快捷、灵敏度 高、成本低等优点,在实际茶叶农药残留检测中得到了广泛应用,能满足日常的茶叶农药残留检测。     

Residue levels and health risk of pesticide residues in bell pepper in Shandong

ABSTRACT

The purpose of this study was to investigate pesticide residues in bell peppers from Shandong Province, China. A total of 299 samples were collected from 17 cities in 2016. The concentrations of 26 pesticide residues were determined by gas chromatography with mass spectrometry (GC–MS). The results showed that there were 25 pesticides (15 OPs, 7 PYs, 3 CBs) found in 86 bell pepper samples, and the total number of positives was 120. The total frequency was 28.76%. The detection frequency for OPs, PYs and CBs was 16.39%, 12.37% and 3.01%, respectively. The most frequently detected pesticide was bifenthrin, with the frequency of 5.02%. 5.35% of samples contained pesticide residues above the maximum residue limits (MRLs) set by China. 7.36% of samples contained more than one pesticide. The values of %ADI were below 100, while the %ARfD of carbofuran and methidathion exceeded 100 for children. The cumulative risk was highest for OPs. From the public health point of view, the levels of pesticide residues in bell peppers do not pose a serious health risk to adults, but the acute health risk to children should be paid more attention.     

宜昌茶叶中农药残留监测及分析

目的监测茶叶农药残留情况,了解宜昌茶叶质量安全现状。方法采集的样品经过Qu ECh ERS方法进行提取、净化,采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)对宜昌市茶叶主产区125批次茶叶样品中25种农药残留进行监测分析,外标法定量。结果所有监测样品中,农药检出39批次,涉及农药6种,检出率31.2%。结论按照GB 2763-2017标准,所检出样品没有超标样品。国家标准缺乏茶叶中部分农药残留最大限量标准,需要进一步完善。