梨果套袋及常用清洗方式对农药残留去除效果研究

目的 研究套袋模式以及常用清洗方式对梨果中农药残留去除效果。方法 在套袋与不套袋梨树上施用6种农药(毒死蜱、高效氯氰菊酯、苯醚甲环唑、戊唑醇、多菌灵、吡虫啉), 采摘期分别取样, 非套袋梨果用4种方式(清水、盐水、苏打水、洗涤精)清洗, 对比套袋与不套袋, 4种方式清洗与不清洗梨果中农药残留量。结果 套袋梨果对比不套袋农药去除率为43%~96%。4种清洗方式相比不清洗的去除率为44%~88%。结论 套袋以及4种清洗方式均能有效去除农药残留, 但存在一定差异, 苏打水清洗去除梨果农药残留效果最佳。     

苹果泥加工及储藏过程中6种农药残留变化

目的 明确苹果泥加工及储藏过程中多菌灵、噻虫嗪、吡虫啉、啶虫脒、咪鲜胺和苯醚甲环唑残留变化规律。方法 通过实验室模拟加工和加速储藏实验, 采用液相色谱-质谱法检测其中多菌灵、噻虫嗪、吡虫啉、啶虫脒、咪鲜胺和苯醚甲环唑的残留变化。结果 建立的检测方法中, 6种农药回收率范围为80.48%~114.58%, 相对标准偏差为2.08%~6.43%, 检出限为0.10~1.25 μg/kg, 定量限为0.50~5.00 μg/kg。苹果泥加工过程中清洗步骤农药残留浓度降低12.93%~38.87%, 预煮步骤农药残留浓度降低24.61%~58.16%, 而巴氏杀菌步骤农药残留浓度略有增加(P>0.05)。加速储藏过程中6种农药残留浓度均降低, 其中咪鲜胺在加速储藏14 d后未检出。苹果泥加工全程及储藏过程中6种农药的加工因子均小于1。结论 研究结果可为苹果泥中农药最大残留限量制定及消费者安全膳食引导提供参考, 获得的加工因子可用于食品安全风险评估, 提升风险评估结果的准确性。     

双孢菇加工工艺中多菌灵等3种农药残留的控制

采用液相色谱-串联质谱法检测4种双孢菇加工工艺产品中的多菌灵、乙霉威和咪鲜胺3种农药残留,并分析降低3种农药残留的关键工艺步骤和参数。结果表明,对多菌灵等3种农药的去除率从大到小依次为罐头、盐渍、速冻和冷冻干燥工艺,其相对残留率范围为3.4%~11.7%、11.5%~22.3%、61.5%~86.1%和150.4%~152.3%。罐头工艺中,清洗和加热是降低3种农药残留的关键步骤,用Na2CO3溶液浸泡清洗25 min具有最佳降低效果,多菌灵去除率可达37.2%;延长预煮时间能够提高3种农药的实际去除率,14 min预煮使多菌灵、乙霉威和咪鲜胺的去除率分别达到22.0%、15.9%和17.1%。     

3 种杀菌剂在北京林地食用菌中的残留与安全性评价

在北京市林地食用菌基地采集不同品种食用菌,监测多菌灵、噻菌灵和咪鲜胺的残留水平。样品用乙腈提取,N-丙基乙二胺和弱阳离子交换吸附剂净化,超高效反相液相色谱分离,三重四极杆质谱检测,基质匹配标准溶液的外标法定量。在添加量为0.01～1.0 mg/kg时,方法的回收率为74%～100%,相对标准偏差为2%～13.0%,咪鲜胺、噻菌灵和多菌灵3 种农药的最小检出量分别为0.003、0.003、0.001 5 ng,最低检出浓度为0.01 mg/kg。林地食用菌样品中噻菌灵的残留量均小于0.01 mg/kg,多菌灵的残留量为0.01～0.42 mg/kg,咪鲜胺的残留量为0.01～0.51 mg/kg。我国规定多菌灵、噻菌灵、咪鲜胺在食用菌中的最大残留限量分别为1.0、5.0、2.0 mg/kg,以此为依据,北京林地食用菌中的多菌灵、噻菌灵和咪鲜胺残留是安全的。     

三唑酮及其代谢物在烟叶中的降解规律

为制定烟叶中三唑酮及代谢产物的农药残留限量,研究了合理使用条件下,三唑酮及其代谢物三唑醇在烟叶中残留降解规律和残留水平。采用气相色谱电子捕获检测器(GC-ECD)建立了同时测定烟叶中三唑酮和代谢产物三唑醇农药残留的检测方法,结果表明:三唑酮在鲜烟叶和烤后烟叶中的最低检出量(LOQ)分别为 0.01、0.05 mg/kg。三唑酮、三唑醇在鲜烟叶和干烟叶样品中添加水平为 0.01~ 5 mg/kg时,平均添加回收率为 79.8%~97.3%, RSD为 1.5%~9.0%,符合农药残留检测方法要求。对 2011-2012年山东、湖南两地三唑酮残留试验的烟叶样品进行了检测。结果表明,三唑酮在自然生长条件下半衰期为 3.8~5.6d,在储存条件下的半衰期分别为 157~315 d。最终残留试验结果表明,施药剂量和采收安全间隔期与烟叶中农药残留量显著相关,末次施药后 7、14、21 d,烤后烟叶中三唑酮及代谢物的残留量分别为 0.33~6.44 mg/kg、0.15~2.77 mg/kg、0.18~2.53 mg/kg。建议三唑酮及代谢产物在烟叶中 MRL为 5mg/kg,安全间隔期(PHI)为 14 d。      

桃胶中多农药残留分析及风险评估

目的:研究桃胶中农药残留及风险。方法:基于液相色谱—串联质谱法(LC-MS/MS)建立桃胶中44种农药残留的定量分析方法,并对全国173份桃胶样品进行农药残留检测和风险评估分析。结果:基于LC-MS/MS农药残留检测方法的检出限(LOD)为0.05～1.80μg/kg,定量下限(LOQ)为0.20～2.42μg/kg,加标回收率为61.77%～119.48%。桃胶样品中共检出22种农药,农药总检出率为98.8%,平均每个样品检出农药次数为2.8次,苯醚甲环唑检出率最高(95%),其次是毒死蜱(54%)、多菌灵(34%)、呋虫胺(32%)、吡唑醚菌酯(19%)等。不同桃胶样品中苯醚甲环唑平均残留量最高为0.332 mg/kg,其次是呋虫胺(0.093 mg/kg)、多菌灵(0.061 mg/kg)、毒死蜱(0.033 mg/kg)。结论:桃胶中农药的残留与桃生产用药有关,其残留量总体处于低风险水平,推荐8—10月份采摘桃胶。     

超高效液相色谱-质谱联用法测定山野菜中5种农药的残留

建立超高效液相色谱-质谱联用法[ACQUITY UPLC/Xevo TQ-S]测定人工栽培山野菜中啶虫脒、吡虫啉、多菌灵、嘧霉胺、苯醚甲环唑5种农药残留。以乙腈为提取溶剂,采用多重反应离子监测(MRM)模式,ACQUITY UPLC BEH C18为分析色谱柱、0.1%甲酸乙酸铵-乙腈为流动相,对样品进行检测分析。结果表明:5种农药在0.0005~2.0000 mg/L范围内与峰面积呈良好线性关系,相关系数在0.9947~0.9999之间。在农药混合标准溶液0.005~0.200 mg/kg的水平下,添加回收率均在73.43%~115.84%之间,相对标准偏差为2.04%~18.19%。检出限在0.020~0.510μg/kg范围内;定量限在0.066~1.699μg/kg范围内。本方法操作简单、快捷、准确度和精密度高,可应用于山野菜中5种农药残留测定。     

QuEChERS-高效液相色谱-串联质谱法检测莲子中8种农药残留

目的 建立一种基于QuEChERS前处理与高效液相色谱-串联质谱(high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS)联用测定莲子中8种农药(多菌灵、甲基硫菌灵、精甲霜灵、戊唑醇、苯醚甲环唑、肟菌酯、吡虫啉、克百威)残留量的分析方法。方法 样品经乙腈和QuEChERS提取包提取，QuEChERS净化管净化，在HPLC-MS/MS系统的多反应监测模式(multiple reaction monitoring, MRM)下进行8种农药的定量和定性分析。结果 8种农药在0.1~250.0 μg/L的范围内呈现良好线性关系，相关系数r2均大于0.998；方法的检出限和定量限分别为0.01~0.09 μg/kg和0.04~0.3 μg/kg；在4个加标水平下(0.3 ug/kg, 0.01、0.10、0.50 mg/kg)，加标回收率为79.1%~97.0%，相对标准偏差(relative standard deviation, RSD)为1.35%~6.44%。结论 本方法的重复性和回收率满足实验要求，适用莲子中部分农药残留的分析检测。     

嘧螨胺在土壤中的残留分析

[目的]建立嘧螨胺在土壤中的残留分析方法。[方法]土壤样品以50 mL乙腈超声提取,高效液相色谱-紫外检测器分析测定。[结果]嘧螨胺在0.1~20.0mg/L范围内具有良好的线性关系,相关系数(r)为0.9965,当添加质量分数为0.2~3.0mg/kg,嘧螨胺在3种土壤中的添加平均回收率为92.9%~105.0%,相对标准偏差(RSD)为0.2%~6.6%。方法最小检出量为5.0×10-10g,土壤中最小检出质量分数(LOQ)为0.2 mg/kg。[结论]该方法操作简单可靠,准确度、精密度及其灵敏度均满足农药残留分析的要求,可用于土壤中嘧螨胺残留量的测定。     

5种农药在采收前和初烤后的烟叶及土壤中的残留量变化

为研究采收前和初烤后烟叶及土壤中三唑酮、霜霉威、稻瘟灵、吡虫啉和仲丁灵残留量的变化,建立了烟叶和土壤中该5种农药残留的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。样品经乙腈提取,N-丙基乙二胺(PSA)吸附剂净化,UPLC-MS/MS法检测,采用基质配制溶液绘制标准曲线,内标法定量。结果表明:1烟叶中5种农残的定量限在12.25~37.48μg/kg之间,加标回收率为74%~117%;土壤中5种农残的定量限在0.11~0.34μg/kg之间,加标回收率为78%~107%。2田间试验表明,于烟叶采收前15 d对烟草植株按最大许可使用量施药后,上部、中部叶中吡虫啉、三唑酮(含其残留的转化物三唑醇)和仲丁灵的残留量随时间逐渐减小;霜霉威和稻瘟灵的残留量随时间先增大后减小;初烤后烟叶中5种农药的最终残留量≤2.70 mg/kg,低于CORESTA规定的指导性残留限量(GRLs)。土壤中吡虫啉残留量随时间逐渐减小;三唑酮、稻瘟灵和霜霉威的残留量随时间先增大后减小;仲丁灵残留量随时间有所增加。     

Effect of processing on the reduction of pesticide residues in a traditional Chinese medicine (TCM)

ABSTRACT

The behaviour of residues of tebuconazole, prochloraz, and abamectin in rehmannia during rehmannia decoction processing was systemically assessed. The pesticides were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each processing step including washing, steaming and drying, carbonising, and boiling. Results showed that the pesticide residues significantly decreased after the steps of washing, carbonising, and boiling. Washing reduced pesticide residues by 41.2%–60.0%; carbonising reduced pesticides by 27.1%–71.1% in both prepared rehmannia and unprepared rehmannia. After boiling, the concentrations of tebuconazole and prochloraz were 0.0002–0.0022 mg kg^?1 in decoctions. Abamectin was not detected in rehmannia after carbonising, and it was not detected in decoctions either. The processing factors (PFs) were less than 1 during food processing, indicating that the full set of processing can reduce the residues of tebuconazole, prochloraz, and abamectin in rehmannia decoction.     

Effect of home processing on the distribution and reduction of pesticide residues in apples

The effect of home processing (washing, peeling, coring and juicing) on residue levels of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim in apple segments was investigated. The pesticide residues were determined by UPLC-MS/MS and GC with a flame photometric (FPD) and electron capture detection (ECD). The results indicated that the pesticide residue levels in the apple peel and core were higher compared with in the apple flesh. After peeled and cored apple was processed into apple juice and pomace, chlorpyrifos, β-cypermethrin and tebuconazole were concentrated in the apple pomace. However, residues of acetamiprid and carbendazim were exceptions. The apple pomace was free of acetamiprid, which was mainly present in the apple juice. After washing the mean loss of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim from apples under recommended dosage and twofold higher dosage were 17-21%, 6.7-7.1%, 13-32%, 42-67% and 47-50%, respectively. The pesticide residues were significantly reduced in the edible part of the apple except for β-cypermethrin during peeling and coring process. The removal effect of apple juicing was found to be the most pronounced on β-cypermethrin residue, which was reduced in the range of 81-84%, and the reductions of chlorpyrifos, tebuconazole, acetamiprid and carbendazim upon apple juicing were in the range of 15-36%.     

Effect of home processing on the distribution and reduction of pesticide residues in apples

The effect of home processing (washing, peeling, coring and juicing) on residue levels of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim in apple segments was investigated. The pesticide residues were determined by UPLC-MS/MS and GC with a flame photometric (FPD) and electron capture detection (ECD). The results indicated that the pesticide residue levels in the apple peel and core were higher compared with in the apple flesh. After peeled and cored apple was processed into apple juice and pomace, chlorpyrifos, β-cypermethrin and tebuconazole were concentrated in the apple pomace. However, residues of acetamiprid and carbendazim were exceptions. The apple pomace was free of acetamiprid, which was mainly present in the apple juice. After washing the mean loss of chlorpyrifos, β-cypermethrin, tebuconazole, acetamiprid and carbendazim from apples under recommended dosage and twofold higher dosage were 17–21%, 6.7–7.1%, 13–32%, 42–67% and 47–50%, respectively. The pesticide residues were significantly reduced in the edible part of the apple except for β-cypermethrin during peeling and coring process. The removal effect of apple juicing was found to be the most pronounced on β-cypermethrin residue, which was reduced in the range of 81–84%, and the reductions of chlorpyrifos, tebuconazole, acetamiprid and carbendazim upon apple juicing were in the range of 15–36%.     

Determination of fungicide residues in baby food by liquid chromatography-ion trap tandem mass spectrometry

Current European Commission Directives on foods for infants and young children places emphasis on the control of pesticide residues at levels below 10 μg kg(-1). In the present work, a liquid chromatography electrospray ionisation ion trap tandem mass spectrometry (LC-Ion Trap-MS/MS) has been developed for the multiresidue of 10 multiclass fungicides (carbendazim, thiabendazole, imazalil, tridemorph, triadimefon, bitertanol, prochloraz, flutriafol, myclobutanil and diphenylamine) in fruit-based baby food. The developed method is based on a simple sample treatment (QuEChERS), which consists of a liquid-liquid extraction using acetonitrile, followed by a clean-up step based on dispersive solid-phase extraction with primary secondary amine (PSA). Subsequent identification and quantitation was accomplished by liquid chromatography/electrospray tandem mass spectrometry using an ion-trap mass spectrometer in the product ion scan MS/MS mode. Matrix effects were evaluated in LC-MS and LC-MS/MS mode experiments, obtaining a reduction of these effects when working in MS/MS mode for most of the analytes. Limits of detection (LOD) were between 0.5 and 3.0 μg kg(-1) depending on the pesticide studied, all being within European Union regulations for baby food. Finally, the proposed method was applied to 25 baby food samples obtained from local supermarkets. Imazalil, thiabendazole and carbendazim were detected in the studied samples. However, none of the samples tested were found to be upper the EU standard.     

餐前加工对辣椒中5种常见农药残留去除的影响

通过研究清洗及烹饪过程对辣椒中百菌清、哒螨灵、腐霉利、氯氟氰菊酯及氰戊菊酯残留的影响,了解农药在加工过程中的变化规律,为膳食暴露评估提供依据。方法 采用实验室浸泡法模拟农药污染试验,并模拟家庭日常加工对辣椒进行清洗、烹饪等处理,通过气相色谱法(ECD)检测加工前后辣椒中农药残留变化。结果 清洗及烹饪对农药残留均有明显影响,以上5种农药在辣椒中经清洗和烹饪后总去除率分别为54.12%～99.47%、58.78%～95.95%、55.74%～93.68%、41.37%～95.67%和44.71%～95.09%;不同烹饪方法对农药的去除作用由强到弱为:油炸>炒制>焯水,且烹饪时间越长,去除作用越大,当烹饪时间超过2 min后,去除作用则不发生明显变化。结论 烹饪对辣椒中农药残留的去除作用比清洗时好,加工对农药的影响受农药的水解、高温分解特性、熔沸点及饱和蒸汽压等性质的共同作用决定。     

分散固相萃取-液相色谱-串联质谱法测定典型小宗作物中6种农药残留

建立生姜、红薯、土豆、荔枝中多菌灵、吡虫啉、涕灭威、三唑酮、乙草胺、苯醚甲环唑的液相色谱-串联质谱检测方法。样品经乙腈溶液提取,50 mg N-丙基乙二胺吸附剂、25 mg十八烷基键合硅胶(C_(18))净化,C_(18)色谱柱分离,0.1%甲酸溶液-甲醇作为流动相进行梯度洗脱,在电喷雾正离子电离模式下,质谱多离子监测模式定量分析,基质标准曲线外标法定量。结果表明,6种农药在10~500μg/L范围内呈良好的线性关系,相关系数(r)均大于0.995。3个加标水平下,6种农药的平均回收率为87.9%~110.3%,相对标准偏差不大于14.6%。该方法简单、快速、灵敏度高,能够满足小宗作物农药残留的监控要求。     

Effect of commercial processing on pesticide residues in orange products

The effect of commercial processing of orange juice on pesticide residues was investigated, and the processing factors of all orange products and by-products were also determined. The pesticide residues were strengthened using field trials and detected using Ultra-performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS). The results showed that the pesticide residues were mainly distributed in orange peels, the reduction of residue levels ranged from 43.6 to 85.4% during washing process. One percent to 4.5% of initial residues contained in the squeezed juice, 7–94.7% of the total relative residues were distributed in pomace. Filtrating could further reduce all the residue levels, ranging from 96.0–99.4% relative to unwashed whole fruits. After sterilization, there was only 0.5–3.1% of the residues contained in Not from Concentrate juice (NFC juice). 0.2–7.1% of the total relative residues was contained in concentrated juice, comparing with the filtrated juice; however, the concentration of cypermethrin and prochloraz was decreased, but the other 3 pesticides were increased. The residue levels of imidacloprid and carbendazim in orange oil were reduced but abamectin, prochloraz, and cypermethrin were concentrated, and the concentrated factor was 28.214, 5.232, and 5.621, respectively.     

米炒党参炮制过程中党参炔苷、5-HMF和党参多糖含量动态变化研究

目的：研究不同米炒党参在炮制过程中党参炔苷、5-HMF和党参多糖的动态变化。方法：高效液相色谱法测定党参炔苷、5-HMF含量,紫外-可见分光光度法测定党参多糖含量动态变化过程。结果：（1）党参炔苷：随着炒制时间的延长,党参炔苷含量均呈先上升后下降趋势;在相同时间间隔点,小米炒党参炔苷含量较高。（2）5-HMF：随着炒制时间的延长,5-HMF含量均呈显著上升趋势;在相同时间间隔点,小米炒党参5-HMF含量较低。（3）党参多糖：随着炒制时间的延长,党参多糖含量均呈先上升后下降趋势;在相同的时间间隔点,炒制时间为5.5min之前的样品中小米炒党参多糖含量均高于大米炒党参,炒制时间为5.5min之后的样品中小米炒党参多糖含量均略低于大米炒党参。结论：党参分别采用小米、大米炒制后,3种成分均发生了显著变化,但小米炒党参和大米炒党参变化趋势不一致。