Solid phase microextraction of pesticide residues from strawberries.

A new solid phase microextraction method for the determination of pesticide residues in strawberries for 16 commonly used compounds was described. The strawberries were crushed and centrifuged. An aliquot of the well agitated aqueous supernatant (4 ml) was extracted with a fibre coated with polydimethylsiloxane (PDMS, 100 microns) for 45 min at room temperature. Identification and quantification were achieved using a gas chromatography-mass spectrometry (GC-MS) system and selective ion monitoring (SIM). The method was tested for the following pesticides: carbofuran, diethofencarb, penconazole, hexaconazole, metalaxyl, folpet, bromopropylate, dichlofluanid, alpha-endosulfan, beta-endosulfan, parathion ethyl, procymidone, iprodione, vinclozolin, myclobutanil and chlorothalonil. Limits of detection, repeatability and linearity for standard calibration in strawberries were obtained. Positive and negative effects of the matrix between the extracting solution of strawberries and water were observed. Stabilities of these compounds in the extracting solution of strawberries were determined. The solvent-free SPME procedure was found to be quicker and more cost effective than the solvent extraction methods commonly used.     

设施栽培草莓中农药残留膳食风险评估

以北京、河北、山东、安徽和辽宁五个设施栽培草莓主产区的120个样品为研究对象,进行88种农药残留分析及膳食摄入风险评估,利用风险排序矩阵对检出农药进行风险排序,并计算最大残留限量估计值。结果表明,120个草莓样品中农药检出率为100%,共检出50种农药,其中23种农药在我国或国际食品法典委员会制定了草莓中最大残留限量值,均未超标;检出农药的慢性和急性膳食摄入风险分别为0.0005%~33.02%(平均值1.39%)和0.01%~72.51%(平均值5.51%),均小于100%;根据农药风险得分排序,检出的农药可划分为4类,其中高风险农药仅有1种,为水胺硫磷,中风险农药有6种,占12.5%,以低风险以下农药为主(41种),占85.4%;建议尽快制定或修订草莓中阿维菌素、敌敌畏和多菌灵等45种农药的最大残留限量值。     

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%).     

Solid-phase microextraction and sample stacking micellar electrokinetic chromatography for the analysis of pesticide residues in red wines

Solid-phase microextraction (SPME) in combination with sample stacking micellar electrokinetic chromatography (MEKC) was studied for the simultaneous determination of 11 multi-class pesticides residues (pirimicarb, metalaxyl, pyrimethanil, procymidone, nuarimol, azoxystrobin, tebufenozide, fenarimol, benalaxyl, penconazole and tetradifon) in red wines samples. Pesticide residues present in the samples were preconcentrated by SPME using poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) fibers and the injection of large sample volumes into the capillary by reversed-electrode polarity stacking mode (REPSM). Validation of the method was carried out. The combination of both preconcentration procedures (SPME and REPSM) allowed the determination of 10 of these pesticides in red wines at concentrations between 0.049 and 1.69 mg/L (i.e., levels well below the maximum residue limits (MRLs) allowed for these compounds in wine grapes, except for pirimicarb). Repeatability and accuracy of the SPME-MEKC-DAD method was verified by five consecutive extractions of spiked red wine samples at three levels of concentration. Apparent recovery values were in the range 90–107%. The potential of the method was demonstrated by analyzing multiple homemade red wine samples from the Canary Islands and two commercial samples. Only pyrimethanil, procymidone and azoxystrobin were found in the homemade samples; among them, the pesticide most frequently detected was procymidone.     

Residues of azoxystrobin, fenhexamid and pyrimethanil in strawberry following field treatments and the effect of domestic washing

Residues of the pesticides azoxystrobin, fenhexamid and pyrimethanil were determined in strawberry after field treatment. The effect of 'home' washing with tap water and a commercially available vegetable detergent on residue levels was also studied. After treatment, azoxystrobin and pyrimethanil residues on strawberry were on average 0.55 and 2.98 mg kg^-1, respectively, values below the maximum residue level (MRL) fixed by the European Union (2.0 and 5 mg kg^-1, respectively), while fenhexamid residues were on average 2.99 mg kg^-1, which is very close to the MRL of 3.0 mg kg^-1, but some samples were over the MRL. Thereafter, all residues declined, with a half-life of about 8 days (azoxystrobin and fenhexamid) and 4.8 days (pyrimethanil). Washing the fruit with tap water reduced the residues of azoxystrobin and fenhexamid but did not affect pyrimethanil residues. Finally, when fruits were washed with a commercial detergent, greater amounts were removed (about 45% of azoxystrobin and pyrimethanil and 60% of fenhexamid).     

Headspace solid-phase microextraction for the evaluation of pesticide residue contents in cucumber and strawberry after washing treatment

The headspace solid-phase microextraction was developed to examine the organophosphorus (diazinon, malathion, chloropyrifos, quinalphos, profenofos) and organochlorine (chlorothalonil, α-endosulfan and β-endosulfan) pesticide residues in vegetable (cucumber) and fruit (strawberry) samples. The effects of washing by different solutions were evaluated for the reduction of organophosphorus and organochlorine pesticide residues contents. Gas chromatography with electron capture detection was used to analysis the investigated pesticides. The results showed that washing by a non-toxic solution can decrease the concentration of pesticide residues in the fruit and vegetable samples. The data further indicated that acetic acid was the most effective solution in removing the residues of the investigated pesticides from the fruit and vegetable samples when compared to sodium carbonate, sodium chloride and tap water. The amount of pesticides removed by solution washing is related to their water solubility and vapour pressure properties.     

安徽某草莓基地土壤中农药残留特征及风险评价

摘 要：目的 调查安徽某草莓基地土壤中的农药残留状况,评估其农药残留风险。方法 采用超高效液相色谱串联质谱法和气相色谱串联质谱法,对采集的205份土壤样品进行农药残留检测分析,并用环境标准值计算法评估草莓基地农药残留风险。结果 该地区205个土壤样品中共有179份样品检出农药残留,检出率87.31%;检出的有30种农药,检出最多的是咯菌腈、腐霉利和苯醚甲环唑3种杀菌剂,检出率分别为83.90%、87.32%、87.32%,对土壤质量安全及种植作物构成一定危害风险。对于表层土（0～20 cm）范围,其浅表层土（0～10 cm）与深表层土（10～20 cm）中的农药残留也有差异,浅表层土（0～10 cm）农药残留浓度高于深表层土（10～20 cm）。结论 该草莓基地由于杀菌剂等农药的长期使用,对土壤质量安全构成风险隐患,需要对高风险农药加强关注。     

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%).     

草莓中嘧霉胺的残留与膳食风险评估

为明确嘧霉胺在大棚草莓中的残留行为及其可能产生的膳食摄入风险,进行了规范的田间残留试验及对不同人群的膳食暴露及风险评估。结果表明:大棚条件下,嘧霉胺在草莓果实上的消解速率符合一级动力学方程,半衰期为4.28 d。400 g/L嘧霉胺悬浮剂以有效成分用量562.5 g a.i./ha和843.75 g a.i./ha施药,分别设置喷施2次和3次,施药间隔期7 d。在最后一次喷药后3、5和7 d采收的草莓中,嘧霉胺最终残留量均不超过我国规定的其在草莓中的最大残留限量值(3 mg/kg)。基于残留试验数据和日平均膳食摄入量及每日允许摄入量(ADI),计算得到我国各类人群中嘧霉胺暴露的风险商(RQ)。结果表明,喷施嘧霉胺后3~7 d内的草莓对2~4岁、18~30岁和60~70岁人群的膳食摄入风险都很低,均在可接受范围之内。     

Processing factors and variability of pyrimethanil, fenhexamid and tolylfluanid in strawberries

An HPLC-MS/MS method for the analysis of three pesticides in strawberries was developed and validated. Recoveries were measured at three spiking levels and ranged from 85 to 99% (mean recoveries). The effects of processing of strawberries ranging from rinsing to jam production were investigated for the three fungicides tolylfluanid, fenhexamid and pyrimethanil, which were applied under field conditions. Kresoxim-methyl was also applied in the field, but was not found in any of the samples investigated. The effect of parameters such as preharvest interval, dose, harvest time and observed pesticide concentration after harvest (initial concentration, mg kg^-1), were examined with respect to possible reduction of the pesticides. The results from rinsing showed that all three pesticides were reduced on average by 37% for tolylfluanid, by 34% for fenhexamid and by 19% for pyrimethanil. For tolylfluanid and fenhexamid, the initial concentration significantly affected the reduction. For fenhexamid, dose could also have a minor influence on reduction. For pyrimethanil, none of the parameters significantly influenced the reduction. For jam production, cooking significantly reduced tolylfluanid by an average of 91%. For fenhexamid and pyrimethanil, a smaller reduction was seen, 25% and 33%, respectively. The reduction of tolylfluanid and pyrimethanil was affected by the preharvest interval, while fenhexamid was affected by the initial concentration. The unit-to-unit variability of fungicide contents was also investigated and the variability factors for the three fungicides were from 1.9 to 2.8.     

Investigation of pesticide residues in vegetables and fruits grown in various regions of Hatay,Turkey

In this study, 175 pesticide residues in various vegetable and fruit samples grown in different regions of Hatay, Turkey, were investigated. Residue analyses were performed using liquid chromatography–tandem mass spectrometry with the QuEChERS method. In tomato, plum and apricot samples, pesticide residues were below the limits of detection. In other samples, at least one pesticide residue was detected. Twelve pesticides (acetamiprid, carbendazim, chlorpyrifos, fenarimol, fludioxonil, hexythiazox, imidacloprid, metalaxyl, pyridaben, pyriproxyfen, thiabendozole, triadimenol) were found at levels between 0.003 and 0.759?mg?kg^?1. Only in cucumber samples, acetamiprid residues were found at levels greater than the maximum acceptable limit in Turkish Food Codex and European Union maximum residue limits (EU MRLs). In other samples, the detected residue amounts are less than the MRLs declared in the Turkish Food Codex and EU MRLs.     

山东潍坊地区黄瓜中623种农药及代谢物残留的快速筛查及风险评估

为了解山东潍坊地区黄瓜的农药残留状况,该研究采用保留指数-气相色谱-串联质谱法对在山东潍坊地区生产和流通环节采集的392份黄瓜样品进行623种农药及代谢物残留的定性筛查和定量检测,并进行农药残留风险评估及排序。结果表明,392份黄瓜样品中共检出55种农药及代谢物,检出率为0.26%~92.09%,筛查出19种现有国标方法（GB 23200.113-2018和GB 23200.8-2016）未覆盖的农药残留;5种农药超出最大残留限量,即螺螨酯（2.30%）、硫丹（1.02%）、甲霜灵（0.51%）、醚菌酯（0.26%）、哒螨灵（0.26%）;检出55种农药残留的慢性和急性膳食摄入风险均低于100%,摄入风险可接受;根据残留风险得分排序,中高风险农药占比较高（60%）,特别是一些禁限用农药（硫丹、2,4-滴丁酯）的检出可能与农业投入品的隐性添加有关;流通环节（33.5%）检出农药数量高于15种的样品占比明显高于生产环节（4.08%）,这一现象可能与从基地到市场的“三前环节”存在风险点,缺乏有效监管有关,建议加强“三前环节”监管和农药使用管理,确保农产品质量安全。     

Residues of insecticides, and fungicides in fruit produced in Ontario, Canada, 1986-1988

Between 1986 and 1988, 306 composite samples of fruit representing eight commodities were collected from farm deliveries to the marketplace in Ontario, Canada. All samples were analysed for insecticides and fungicides. The analysis procedure included tests for organochlorine, organophosphorus, synthetic pyrethroid and methylcarbamate insecticides and dithiocarbamate, dicarboximide and organochlorine fungicides. The commodities tested included apples, blueberries, cherries, grapes, peaches, pears, raspberries and strawberries. In 14% of all fruit samples, pesticide residues were below the detection limits, which ranged between 0.005 and 0.02 mg/kg. A further 14% had total combined pesticide residues below 0.1 mg/kg. Total combined fungicide and insecticide residues ranged from 0.1 to 11 mg/kg in 72% of samples. Six different pesticides were in violation of maximum residue limits (MRL) on 11 (3.6%) of fruit samples. Captan exceeded the 5 mg/kg MRL in five samples and EBDC exceeded the 7 mg/kg MRL in two. Other violations included single fruit samples with dicofol, endosulphan, phosalone and iprodione above the MRL. Raw grapes harvested for wine contained residues of 10 pesticides and the number changed little following the crushing of the grapes; however, fermentation into wine significantly reduced residues. Six insecticides and four fungicides were present on the raw grapes and 4/105 were above the MRL. Following crushing, four insecticides and five fungicides were identified and 4/40 were above the MRL. In wine only three insecticides were identified and all were well below the MRL. Carbaryl appeared to be the most persistent, declining very little between raw grapes and wine.     

Analysing organochlorine pesticides in strawberry jams using GC-ECD, GC-MS/MS and QuEChERS sample preparation

This paper describes a comparison of adaptations of the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach for the determination of 14 organochlorine pesticide (OCP) residues in strawberry jam by concurrent use of gas chromatography (GC) coupled to electron capture detector (ECD) and GC tandem mass spectrometry (GC-MS/MS). Three versions were tested based on the original QuEChERS method. The results were good (overall average of 89% recoveries with 15% RSD) using the ultrasonic bath at five spiked levels. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), were determined for each pesticide. LOD ranged from 0.8 to 8.9 μg kg(-1); LOQ was in the range of 2.5-29.8 μg kg(-1); and calibration curves were linear (r(2)>0.9970) in the whole range of the explored concentrations (5-100 μg kg(-1)). The LODs of these pesticides were much lower than the maximum residue levels (MRLs) allowed in Europe for strawberries. The method was successfully applied to the quantification of OCP in commercially available jams. The OCPs were detected lower than the LOD.     

贵州黔东南州番茄农药残留膳食摄入风险评估

为明确贵州黔东南州番茄中农药残留膳食摄入风险和现有农药最大残留限量（maximum residue limits,MRL）标准对消费者的保护水平,采用国家估计每日摄入量和国家估计短期摄入量对儿童和一般人群进行农药残留膳食摄入风险评估,用现有农药MRL标准的理论最大每日摄入量和理论最大短期摄入量对消费者的保护水平进行评估,并利用风险排序矩阵对检出农药进行风险排序。结果表明：番茄中共检出26 种农药,检出率为2%～20%;4 种农药残留超标,超标率为2%～4%。在儿童和一般人群中,氟虫腈慢性膳食摄入风险分别为459%和214%,其他农药慢性膳食摄入风险范围分别为0.008 40%～23.7%和0.003 92%～11.0%。儿童和一般人群的急性膳食暴露风险范围分别在0.015 6%～56.0%和0.006 85%～24.6%之间。农药MRL标准对儿童的慢性风险保护水平（consumer protection level for chronic dietary risk,CPLc）为0.304～60.9,急性风险保护水平（consumer protection level for acute dietary risk,CPLa）为0.462～153;现有农药MRL标准对一般人群的CPLc为0.652～130,CPLa为1.05～349。高风险农药氟虫腈对各类消费者均存在不可接受的慢性风险,除此之外其他农药残留的慢性风险和所有农药残留的急性风险均在可接受范围之内。丙溴磷和百菌清MRL标准对不同年龄阶段消费者慢性风险的保护均未达到可接受水平,异菌脲MRL标准对4～6 岁儿童急性风险的保护未达到可接受水平。因此,贵州黔东南州番茄应重点关注丙溴磷、百菌清、异菌脲以及氟虫腈等高风险农药。     

Safe apples for baby-food production: Survey of pesticide treatment regimes leaving minimum residues

A total of 19 pesticide preparations were used according to agricultural practice in six trials in apple orchards. Using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), premature Golden Delicious apples collected 64, 50, 36 days before harvest and mature fruit were examined for residues of active ingredients. No residues of triflumuron, triazamate, chlorpyrifos, etofenprox, fenoxycarb, kresoxim-methyl, cyprodinyl, difenoconazole or thiram were detected in the first sampling. Also, the levels of chlorpyrifos-methyl, penconazole, tebuconazole and tolylfluanid dropped during the pre-harvest interval. Detectable residues of pyridaben, thiacloprid, trifloxystrobin and tetraconazole in harvested fruits were below 0.01 mg kg^-1, which is the maximum concentration of residues acceptable by baby-food producers in any raw material. The only residues exceeding this concentration were captan and teflubenzuron. Based on the data, farmers can choose pesticides for optimal treatment of plants, while enabling growth of a safe crop suitable for baby-food production.     

Determination of pesticide residues in olive oils with protected geographical indication or designation of origin

Seventy olive oil samples with protected geographical indication (PGI) or designation of origin (PDO) were analysed for fifty‐one target pesticides by means of gas chromatography coupled to mass spectrometry. The highest detection rates were observed for penconazole (n = 20), α‐endosulfan (n = 18), β‐endosulfan (n = 16) and flufenoxuron (n = 12). Four of the seventy investigated samples contained pesticide residues in levels exceeding MRLs. However, the investigated samples showed decreased occurrence and levels of pesticides residues in comparison with previous studies concerning samples from Greek conventional and organic cultivations. According to Spearman matrix, powerful correlations were obtained between α‐endosulfan and β‐endosulfan, detected as pair in thirteen samples and between flufenoxuron and penconazole detected as pair in eleven samples. Among Greek olive oil samples, the Cretan ones showed the lower detection rates and the lowest average number of detected pesticides per sample (1.75) in the case of pesticides positive samples.     

Analysing organochlorine pesticides in strawberry jams using GC-ECD,GC-MS/MS and QuEChERS sample preparation

This paper describes a comparison of adaptations of the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach for the determination of 14 organochlorine pesticide (OCP) residues in strawberry jam by concurrent use of gas chromatography (GC) coupled to electron capture detector (ECD) and GC tandem mass spectrometry (GC-MS/MS). Three versions were tested based on the original QuEChERS method. The results were good (overall average of 89% recoveries with 15% RSD) using the ultrasonic bath at five spiked levels. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), were determined for each pesticide. LOD ranged from 0.8 to 8.9?µg?kg^?1; LOQ was in the range of 2.5–29.8?µg?kg^?1; and calibration curves were linear (r ^2?>?0.9970) in the whole range of the explored concentrations (5–100?µg?kg^?1). The LODs of these pesticides were much lower than the maximum residue levels (MRLs) allowed in Europe for strawberries. The method was successfully applied to the quantification of OCP in commercially available jams. The OCPs were detected lower than the LOD.     

Pesticide residues in raspberries (Rubus idaeus L.) and dietary risk assessment

The aim of this study was to evaluate the residues of 140 pesticides in raspberries from north-eastern Poland (2005–2010). Gas chromatography with electron capture detector (GC-ECD) and nitrogen phosphorous detector (GC-NPD) was used. Among the 128 samples, 66 (51.6%) were found to detect residues: 14.1% contained one pesticide and around 38% multiple pesticide residues. The most frequently detected were pyrimethanil residues (36.0%). Twenty-seven (21.1%) raspberry samples exceeded the maximum residue limits. The estimated daily intakes ranged from 0.003% to 3.183% of the acceptable daily intake (ADI) for adults 0.008% and 9.7% for toddlers, respectively. The most critical case is procymidone, the acute risk was 180.9% of acute reference dose (ARfD) for toddlers and for adults (83% of ARfD) which is high.     

Triazole fungicide degradation in peaches in the field and in model systems

The degradation of five triazole fungicides (cyproconazole, hexaconazole, penconazole, propiconazole, tebuconazole) in peaches was evaluated in field studies to establish whether at the preharvest interval the residue levels were below the legal limit established in Italy. All fungicides, except propiconazole, showed higher residues than the legal limits because of their high stability. In fact, some did not decrease at all (cyproconazole, penconazole, tebuconazole), while others decreased only in part. The increasing weight of the fruit during growth was the main factor leading to an apparent decrease in pesticide levels on a weight for weight basis. The trials on model systems showed that co-distillation and sunlight photodegradation were the main mechanisms leading to a decrease in triazole levels. Although these fungicides are systemic, they did not enter the fruit and all residues were only present in the peel.