A rapid multi-residue method for the determination of pesticide residues in choi sum, yardlong beans and aubergines

A rapid multi-residue modified QuEChERS method has been developed to analyse 20 pesticide residues in choi sum, yardlong beans and aubergines by gas chromatography with flame photometric and electron capture detectors. Primary secondary amine in dispersive form was omitted in the extraction step but instead packed in a Pasteur glass pipette for column cleanup. The recoveries for all 20 pesticides except chlorothalonil at 10-500 μg kg⁻¹ fortification levels ranged from 74.0% to 117%. Similar recoveries of 81.7-117% were obtained for all organochlorine and pyrethroid pesticides including chlorothalonil using silica gel cleanup. The relative standard deviation obtained was below 14.9%. The limit of quantification was in the range 1-10 μg kg⁻¹. The method has high selectivity for pesticides in vegetables containing high amount of chlorophyll, pigment and coloured compounds such as in choi sum and aubergines. The method was used to analyse 132 vegetable samples from residue survey.     

Effect of paste processing on residue levels of imidacloprid,pyraclostrobin, azoxystrobin and fipronil in winter jujube

The changes of imidacloprid, pyraclostrobin, azoxystrobin and fipronil residues were studied to investigate the carryover of pesticide residues in winter jujube during paste processing. A multi-residue analytical method for winter jujube was developed based on the QuEChERS approach. The recoveries for the pesticides were between 87.5% and 116.2%. LODs ranged from 0.002 to 0.1 mg kg^–1. The processing factor (Pf) is defined as the ratio of pesticide residue concentration in the paste to that in winter jujube. Pf was higher than 1 for the removal of extra water, and other steps were generally less than 1, indicating that the whole process resulted in lower pesticide residue levels in paste. Peeling would be the critical step for pesticide removal. Processing factors varied among different pesticides studied. The results are useful to address optimisation of the processing techniques in a manner that leads to considerable pesticide residue reduction.     

QuEChERS-Based Methods for the Determination of Pesticide Residues in a Dill Using Gas Chromatography with Electron Capture and Nitrogen Phosphorus Detection

In this study, three QuEChERS-based methods of improving sample extract preparation through reduction of unwanted matrix background for pesticide residue analysis in dill (a chlorophyll-containing matrix) were developed and compared. These methods involved the use of (1) dispersive solid-phase extraction (dispersive-SPE), (2) dispersive-SPE combined with liquid–liquid extraction (LLE), and (3) only LLE. Samples were analyzed by gas chromatography with electron capture and nitrogen phosphorus detection (GC-ECD/NPD). The results indicated that cleanup with primary secondary amine (PSA) and graphitized carbon black (GCB) sorbents followed by final solvent exchange from acetonitrile to petroleum ether was the best alternative of the tested methods, resulting in the cleanest extracts. The matrix effect of dill on the most favorable method herein was not significant, and the calibration performed well, with R ²?≥?0.99. The overall recoveries at three spiking levels of 0.01, 0.1, and 1.0 mg kg^?1 fell in the range between 73 and 110 % (95 % on average) with relative standard deviation (RSD) values equal to or lower than 12 % (5 % on average). Uncertainty for the studied pesticides ranged from 7 to 14 % (with the overall average uncertainty of 11 %). Analyses of real samples revealed the presence of pesticides unapproved for use on dill, as well as exceedances of the maximum residue levels (MRLs) for some pesticides. The samples with residue violation results were also confirmed by gas chromatography–tandem mass spectrometry (GC-MS/MS). The proposed method of sample preparation and chromatographic analysis is sufficient and can be applied with all certainty to determine pesticide residues in dill and other plants of high pigment content, i.e., chlorophyll.     

西安市猕猴桃主产区农药残留风险评估

目的通过对西安市猕猴桃进行系统的农药残留情况及膳食暴露风险分析,明确猕猴桃农药残留风险状况。方法对2018年西安市周至县14个猕猴桃主产乡镇共200批次样品进行农药残留定量检测分析,用每日允许摄入量和急性参考剂量进行慢性膳食摄入风险评估和急性膳食摄入风险评估,利用猕猴桃大份餐、每日允许摄入量和人均参考体重计算最大残留限量估计值。并参照兽药残留风险排序矩阵方法(英国兽药残留委员会)对农药和样品进行风险排序。结果 200个猕猴桃样品中有137个样品检出了农药残留,未有超标农药和禁用农药检出;在检出的14种农药中,慢性膳食摄入风险和急性膳食摄入风险均值远远小于100%;将14种检出农药按照风险得分分为Ⅲ类,第Ⅰ类为高等风险农药,共1种;第Ⅱ类为中等风险农药,共0种;第Ⅲ类为低等风险农药,共有13种;以风险指数排序,低风险样品占35.5%,极低风险样品占64.5%,检出农药残留种类为3个以上的样品有占比5.5%,检出农药残留种类为1～2个的样品占比61.5%,未检出农药残留有66个样品,占比33%。结论西安市周至县猕猴桃农药残留处于低风险状态,但仍然要加强日常监管工作。     

QuEChERS-气相色谱-质谱法测定土豆中109种农药残留

建立土豆中109种农药残留的气相色谱-质谱(GC-MS)检测方法。方法 土豆样品以乙腈提取后,经N-丙基乙二胺(PSA)分散固相萃取净化(d-SPE),采用电子轰击电离源(EI)和负化学电离源(NCI)两种电离模式进行GC-MS测定。结果 各农药的定量限在0.001～0.010 mg/kg之间,对空白土豆样品的平均加标回收率为72.7%～118.7%,RSD在1.1%～17.3%之间。在EI模式下,土豆基质对绝大多数农药具有明显的基质效应,因此采用基质匹配标准曲线进行定量分析。应用此方法对欧盟农药残留参比实验室组织的国际比对考核的土豆样品进行定性筛查和定量测定,共检测出13种农药残留,含量范围在0.002～1.669 mg/kg之间,所提交的测定结果的Z评分值在-1.00～1.00之间。结论 本方法简便快速、准确、灵敏度高,适用于农产品中农药多残留的分析。     

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.     

气相色谱-质谱法结合固相萃取技术同时测定番茄中53种农药残留

建立气相色谱串联质谱法结合固相萃取技术同时检测番茄中53种农药残留物的分析方法。样品经乙腈与水提取,C18柱与NH2固相萃取柱进行净化,正己烷定容后,采用气相色谱-质谱联用法测定,外标法定量。53种农药在基质中的线性范围良好,检出限达到我国现行农药残留限量标准;大部分农药化合物加样回收率均在60.0%~120.0%,相对标准偏差为3.2%~15.4%,该方法操作简便,灵敏度较高,且净化效果好,可以满足实际检测需求,也为其他果蔬中农药残留检测提供方法借鉴。     

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 multiresidue determination of pesticides in livestock muscle and liver tissue via modified QuEChERS sample preparation and LC-MS/MS

ABSTRACT

Many multiresidue methods for the determination of pesticides in vegetables and fruits have been reported to date. However, few such methods have been employed to investigate pesticide residues in animal tissue. In this study, an LC-MS/MS multiresidue method coupled with modified QuEChERS extraction was developed and validated for the investigation of eight pesticide residues: prallethrin (PR), resmethrin (RMT), imidacloprid (IMC), diflubenzuron (DFB), cyromazine (CYR), etofenprox (EFP), dinotefuran (DNT) and phthalthrin (PTLT). This method involves initial extraction in a water/acetone system, the addition of salts and a subsequent extraction/partitioning step and, finally, a clean-up step utilising dispersive solid-phase extraction (SPE). The mean recoveries of seven of the pesticides (the exception being CYR) ranged between 74.7% and 113.5%, and the CVs of the livestock tissue – bovine, swine, and chicken muscle and liver tissue spiked at 10 ng g^–1 (50 ng g^–1 for RMT and DNT) and 100 ng g^–1 – were < 13.8%. The recoveries of CYR in all muscle and liver spiked samples ranged from 56.9% to 78.3%, while those of RMT in swine liver were > 120%. Therefore, this method was considered as being unsuitable for the investigation of these samples. The limits of quantitation (LOQs) of seven of the investigated pesticides (the exception being swine liver) in the tissue samples ranged from 0.9 to 15.2 ng g^–1. We therefore concluded that this LC-MS/MS multiresidue method is a valid and suitable for the investigation of seven pesticides in animal tissue, but it is unsuitable for the analysis of CYR in all animal tissues and RMT in swine liver tissue.     

Quantitative analysis of pesticide residues in vegetables and fruits by liquid chromatography quadrupole time-of-flight mass spectrometry

The applicability of liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) for the quantitative analysis of pesticide residues in vegetables and fruits was demonstrated. The LC-QTOF-MS parameters, such as cone voltage, capillary voltage, collision energy and mass extraction window, were carefully optimised for the analysis of pesticide residues. The LC-QTOF-MS method was validated for 149 pesticides in four vegetables and fruits, i.e. apple, potato, cabbage and spinach, at a spiking level of 0.01 mg kg^?1. The samples were prepared according to the Japanese official multi-residue method with a modification to the column clean-up procedure. Of the 149 pesticides, recoveries in the range of 70–120% were achieved for 147 pesticides in apple, 145 in potato, 141 in cabbage and 131 in spinach, with intra-day precisions (RSDs) of < 25% and inter-day precisions (RSDs) of < 30%, which are within the acceptable range given in the Japanese method validation guideline. Matrix effects were negligible for the majority of the target pesticides. Except for spiroxamine in spinach, no interfering peaks were observed in the blank samples. The target pesticides, except those with low sensitivity, achieved calibration curves with satisfactory linearity, with correlation coefficients (r) greater than 0.995 in the concentration range of 0.002–0.1 μg ml^?1. Furthermore, the majority of the target pesticides provided more than one fragment ion or isotope ion that could be used for confirmation. The overall results suggest that LC-QTOF-MS is a powerful tool for the quantification of pesticide residues in vegetables and fruits at the level of 0.01 mg kg^?1.     

Modification of Multiresidue QuEChERS Protocol to Minimize Matrix Effect and Improve Recoveries for Determination of Pesticide Residues in Dried Herbs Followed by GC-MS/MS

An accurate, rapid, and reliable multiresidue QuEChERS method based on gas chromatography coupled with tandem mass spectrometry was developed for the determination of 235 pesticides in challenging, dry, complex herb matrices (Centaurea cyanus L., Matricaria chamomilla L., Thymus vulgaris L.). Sample mass and the type of cleanup sorbent used to estimate the procedure’s effectiveness were optimized. Purification steps with ChloroFiltr, ENVI-Carb, GCB, octadecyl, PSA, and Z-Sep as cleanup sorbents and a step without purification were compared. To minimize the matrix effect and obtain acceptable recoveries for pesticides, 2 g of herb sample and 10 mL acetonitrile, followed by d-SPE cleanup step with a combination of 150 mg PSA/45 mg ENVI-Carb/900 mg MgSO₄, and additionally 50 μL of 5% formic acid and some droplets of dodecane, were needed. Matrix effects for the vast majority of pesticides were reduced (>?20%), showing suppression or enhancement. Most recoveries were in the range of 70–120% (RSD < 18%), reaching the quantification limit of 0.001 to 0.002 mg kg^?1. There was excellent linearity within the range from 0.001 to 2.00 μg mL^?1, and a correlation coefficient higher than 0.999 was obtained. Expanded measurement uncertainty was estimated to be between 4 and 43%. Finally, the developed method was successfully employed to identify and quantify pesticide residues in the analysis of 46 real herb samples.     

Marine-derived bioactive materials for neuroprotection

A sensitive and specific liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of 56 residual pesticides from commercial crops. For a validation of the method, the recoveries, linearities, limits of detection (LOD), and limits of quantitation (LOQ) of the 56 pesticides were investigated. The linearities, LOD, and mean recoveries of the pesticides ranged 0.9686–0.9999, 0.00–11.54 μg/kg, and 65–82%, respectively. This method was evaluated by its application to monitor 345 agricultural products collected from 9 provinces in Korea 2011. Fifteen pesticides were detected from 39 samples and 2 or more residual pesticides were found in 7 samples. However, none of the compounds were observed above the corresponding maximum residue level. The results reflect that the detected pesticide residues were in a safe range and that residual pesticides in the agricultural products in Korea were properly controlled.     

Determination of Some Endocrine-Disrupting Metals and Organochlorinated Pesticide Residues in Baby Food and Infant Formula in Turkish Markets

There is a paucity of data in respect of the nutritional quality of complementary foods for infants and young children aged between 6 and 12 months. In this study, we developed and validated an analytical method for determination of the endocrine-disrupting organochlorine pesticides (OCPs) and elements (As, Cd, and Pb) in infant formula and baby foods. Therefore, it found out the contamination level of the both OCPs and some trace metals (As, Cd, and Pb) in widely consumed infant formula and baby food in Turkey. Metal concentrations in baby foods and infant formula were determined by inductively coupled plasma mass spectrometry. Samples were digested with nitric acid and hydrogen peroxide in a microwave oven. Determination of 24 organochlorine pesticide residues in baby foods and infant formula was completed by using gas chromatography double mass spectrometry. QuEChERS extraction method was carried out in the sample preparation part. The analytical performance of the entire procedure, such as linearity, the detection of limit, limit of quantification, specificity/selectivity, recovery (%), and precision, were assessed. The recoveries ranged from 93% (As) to 100% (Pb) for elements 78–98% for organochlorine pesticide residues (OCPs) at 100 ng mL^?1. According to the results, lead, cadmium, and pesticides were not detected in any of the samples, while arsenic was detected in 16 samples.     

芹菜农药残留风险评估

目的 评估芹菜样品的农药残留风险, 为生产上安全合理使用农药及制订农药最大残留限量标准提供参考依据。方法 随机抽取基地30份芹菜样品, 检测68种农药残留, 分别运用风险系数法、慢性膳食摄入风险(acceptable daily intake, ADI)评估法、急性膳食摄入风险(acute reference dose, ARfD)评估法、风险矩阵排序法进行芹菜农药残留风险评估。结果 芹菜农药残留合格率为70.00%, 超标农药为甲拌磷、二甲戊灵、阿维菌素、对硫磷。甲拌磷、对硫磷、阿维菌素和二甲戊灵的风险系数R﹥2.5, 为高风险农药, 其余农药为低风险。慢性膳食摄入风险及急性膳食摄入风险均在可接受范围内。风险矩阵排序位于前五位的分别是甲拌磷、对硫磷、阿维菌素、异丙威、联苯菊酯。结论 芹菜种植中农药残留超标率较高, 其中甲拌磷风险最大, 其次为对流磷和阿维菌素等, 应重点监控芹菜种植中这些农药的使用。     

Simultaneous determination of three pesticides and their metabolites in unprocessed foods using ultraperformance liquid chromatography-tandem mass spectrometry

We have developed a rapid, multi-compound analytical method for measuring residues of the pesticides thiamethoxam and its metabolite, clothianidin; fipronil and its three metabolites, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl; and pyraclostrobin in unprocessed foods (rice, corn, cucumbers, tomatoes, apples, and bananas) by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Acetonitrile was used as the extraction solvent, and an octadecylsilane-dispersive SPE was used to clean up the analytes, which were then separated through a UPLC HSS T3 column connected to a tandem mass spectrometer via an electrospray ionisation source. The linearity of this method for the target analytes was excellent (R² ≥0.990) in the concentration range of 5–1000 μg kg^–1. The average recoveries of the seven compounds at concentrations of 10, 100, and 1000 μg kg^–1 from six spiked matrix samples ranged from 73.6 to 110.6%, all with RSD values of ≤19.7%. The limit of quantification was 10 μg kg^–1. The method validated the effectiveness of the method for routine monitoring the residue of these pesticides and their metabolites in foods.     

Simultaneous multiresidue analysis of 41 pesticide residues in cooked foodstuff using QuEChERS: Comparison with classical method

The principal objective of this study was to develop a simple multiresidue method involving a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method for the identification and quantification of 41 pesticide residues in cooked foodstuffs including cooked potatoes, radishes, and rice using GC-μECD. The analytes were subsequently confirmed via GC–MS. The results were then compared using the classical method established by the KFDA. The quantitation of individual pesticides was based on matrix-matched calibration curves with a correlation coefficient in excess of 0.993 for the 41 pesticides selected herein. Using QuEChERS, the mean recoveries ranged between 68.6 and 130.0% for the majority of the tested pesticides; however, the classical method exhibited low recoveries for dichlofluanid, tetraconazole, oxadixyl, fenbuconazloe, and paclobutrazol. After QuEChERS, the LODs and LOQs ranged between 0.004 and 0.3 μg/kg and 0.0125 and 1.0 μg/kg, respectively. The proposed method was applied successfully to determine the residue levels in cooked foodstuffs, and none of the samples contained detectable amounts of pesticide residues.     

鸡蛋、鸡肉及奶粉中22种有机氯农药残留的测定

建立了在鸡蛋、鸡肉和奶粉中同时测定22种有机氯农药残留的方法。样品经乙腈提取、Captiva EMR-Lipid固相萃取柱净化、正己烷复溶后,用气相色谱仪检测,外标法定量。在0.005~0.2 mg/L范围内,22种有机氯农药的质量浓度与其对应的峰面积之间线性关系良好,R²均大于0.995。在0.01、0.02、0.1 mg/kg 3个添加水平下,重复测定6次,22种有机氯农药的回收率均在60%~110%,RSD均小于10%,符合GB 27404—2008的实验室内变异系数要求。该方法能够有效去除鸡蛋、鸡肉和奶粉中的动物脂肪及亲脂性干扰物,方法灵敏度、准确度和精密度均符合农药残留检测的要求,为有效监测鸡蛋、鸡肉和奶粉中有机氯农药残留量提供了一种高效、可靠的分析手段。     

Optimization of the QuEChERS Method for Determination of Pesticide Residues in Chicken Liver Samples by Gas Chromatography-Mass Spectrometry

The goal of this research was to evaluate the application of Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method for the determination of organochlorine, organophosphate, and carbamate pesticides in fatty animal matrices such as liver of chicken obtained from National Research Institute of Animal Production in Balice (Poland). Pesticides extraction effectiveness was evaluated at two different spiking levels (0.010 and 0.020 mg kg^?1) and efficiency of the dispersive solid-phase extraction (d-SPE) clean-up step was evaluated by comparison adding different d-SPE sorbent combinations (PSA?+?GCB, PSA?+?C₁₈, PSA?+?SAX, and PSA?+?NH₂). The analysis of pesticide residues was performed by gas chromatography ion trap mass spectrometry (GC/IT-MS). The linear relation was observed from 0 to 400 ng mL^?1 and the determination coefficient R ²?>?0.997 in all instances for all target analytes. Better recoveries were obtained in samples at 0.020 mg kg^?1 spiking level. The recoveries were in the range 70–120 %, with relative standard deviation (RSD) values lower than 15 % at 0.020 mg kg^?1 spiking level for most pesticides. Similar recovery ratios were obtained with the four different combinations of sorbents tested in the clean-up step, with better precision when the (PSA?+?SAX) combination was tested. Limits of detection (LODs) ranged from 0.001 to 0.005 mg kg^?1 and limits of quantification (LOQs) ranged from 0.003 to 0.015 mg kg^?1. The proposed method was successfully applied analyzing pesticide residues in real chicken liver samples; detectable pesticide residues were observed, but in all of the cases, the contamination level was lower than the default maximum residue levels (MRLs) set by European Union (EU), Regulation (EC) N 396/2005.     

Pesticide residues in apples grown under a conventional and integrated pest management system

This paper describes method validation for determination of more than 40 pesticides in apples using a GC technique. Target compounds belonged to the organochlorine, organophosphorus, carbamates, pyrethroids, triazoles, dicarboximides and strobilurins groups, among others. Sample preparation consisted of acetone extraction and subsequent cleanup/concentration by SPE with a polymer-based sorbent. Single quadrupole GC–MS operating in SIM mode and electron impact ionization was used for identification and quantification of the pesticides. Average recoveries for analytes ranged between 70 and 110% at three fortification levels – 0.01, 0.1 and 0.2 mg kg^?1. Relative standard deviations were lower than 20% for all tested compounds. Calculated limits of detection and limits of quantification were below 0.01 mg kg^?1, which were sufficiently low compared to the maximum residue levels (MRLs) established by European legislation. The proposed method was applied for determination of pesticide residue in four selected apple varieties after harvesting. Whole and processed fruits (peel and peeled fruits) were analyzed from different treatment systems: two conventional, one based on integrated pest management (IPM) and two variants based on organic production (controls). Higher levels of pesticide residues were found in apple fruits under conventional conditions. Fenitrothion and chlorpyrifos residues were detected frequently in apple peel at concentrations up to 0.45 and 0.77 mg kg^?1, respectively. The levels found in the whole fruits of the same samples were much lower than in peel and below the respective MRLs (0.5 mg kg^?1 for both pesticides). Measurable residues of triadimenol only, up to 0.05 mg kg^?1, concentrated in the peel, were found in the apples from IPM.     

进口粮谷中农药残留状况普查与分析

目的根据各进口国粮谷样品农药残留检出情况,确立进口粮谷中重点监测的农药残留品种和评估潜在的农药残留风险。方法采用修改的GB/T 19649-2006和GB/T 20770-2008方法,对粮谷主要进口口岸青岛、深圳和秦皇岛在2010~2014年期间进口的62例大豆、62例大麦和28例大米样品进行了690种农药残留检测,共获得104880个检测数据。结果来自6个进口国的62例大豆样品均未检出农药残留。来自3个进口国的62例大麦样品中,有8例样品检出5种农药,检出率12.9%;其中检出1种农药的样品占4.8%,检出2种农药的样品占6.5%,检出3种农药的样品占1.6%;检出的农药残留水平在10~1000μg/kg范围的占检出总数的85.7%,大于1000μg/kg占检出总数的14.3%。来自6个进口国的28例大米样品中,有5例样品检出5种农药,检出率17.9%;其中检出1种农药的样品占14.3%,检出2种农药的样品占3.6%;检出的农药残留水平低于10μg/kg占检出总数的50.0%,大于10μg/kg占检出总数的50.0%。大麦和大米样品中检出的农药品种为低毒农药的均占80%,检出的农药为中毒农药的均占20%。按照中国最大残留限量(MRL)标准衡量,只有1例大麦样品检出的溴氰菊酯超出标准要求;按照欧盟MRL标准衡量,4例大麦样品检出的杀螟硫磷超出标准要求;按照日本MRL标准衡量,没有样品检出超标农药。结论我国进口粮谷的农药残留检出率低于10%。农药残留水平处于安全水平。但同时也应当加强溴氰菊酯、杀螟硫磷、甲基嘧啶磷、毒死蜱、甲基毒死蜱、丙环唑、嘧菌酯、增效醚的检测,特别是溴氰菊酯和杀螟硫磷农药残留的监控,以保障消费者的食品安全。