Dietary exposure to chlorinated pesticide residues in fruits and vegetables from Ghanaian markets

Analysis of 400 fruit and vegetable samples obtained from open and closed markets in Accra, Ghana was carried out employing a multi-residue method based on solid-phase extraction followed by gas chromatography–mass spectrometry. Generally, the data showed that most of the fruit and vegetable samples analysed contain residues of the monitored pesticides below the accepted maximum residue limit (MRL) as adopted by the Food and Agricultural Organization/World Health Organization (FAO/WHO) Codex Alimentarius Commission (CAC), although some pesticide residues were not detected in some of the fruit and vegetable samples. The results obtained further revealed that 20% of the fruit and vegetable samples were above MRL, 73% were below MRL and 7% contained no detectable level of the monitored pesticides. Estimation of dietary intake of pesticides from fruit and vegetables revealed that, pesticides detected in fruits and vegetables did not cause dietary intake risks. The results recommend the need for regular monitoring for pesticide residues of a greater number of samples for long periods, especially in fruit and vegetables, to protect consumers’ health.     

Chronic dietary risk characterization for pesticide residues: A ranking and scoring method integrating agricultural uses and food contamination data

A method has been developed to identify pesticide residues and foodstuffs for inclusion in national monitoring programs with different priority levels. It combines two chronic dietary intake indicators: ATMDI based on maximum residue levels and agricultural uses, and EDI on food contamination data. The mean and 95th percentile of exposure were calculated for 490 substances using individual and national consumption data. The results show that mean ATMDI exceeds the acceptable daily intake (ADI) for 10% of the pesticides, and the mean upper-bound EDI is above the ADI for 1.8% of substances. A seven-level risk scale is presented for substances already analyzed in food in France and substances not currently sought. Of 336 substances analyzed, 70 pesticides of concern (levels 2-5) should be particularly monitored, 22 of which are priority pesticides (levels 4 and 5). Of 154 substances not sought, 36 pesticides of concern (levels 2-4) should be included in monitoring programs, including 8 priority pesticides (level 4). In order to refine exposure assessment, analytical improvements and developments are needed to lower the analytical limits for priority pesticide/commodity combinations. Developed nationally, this method could be applied at different geographic scales.     

顶空气相色谱法测定鸡骨草总黄酮碳苷提取物中大孔吸附树脂残留物

目的：建立同时测定鸡骨草总黄酮碳苷提取物中8种大孔吸附树脂残留物的顶空气相色谱分析方法。方法：采用Supelco-wax毛细管柱（30m×0．25ram×0．25μm）,体积分数为50％的N,N-二甲基甲酰胺（DMF）为溶解介质,高纯氮作为栽气,FID检测器;进样口温度210℃,检测器温度230℃,柱温先在70℃维持8min,再以10℃／min的速度升至220℃,维持7min。结果：在以上色谱条件下,各组分在所考察的浓度范围内均具有良好的线性,r为0．9965～0．9999,RSD为1．839％～9．155％,苯、正己烷、甲苯、间二甲苯、邻二甲苯、对二甲苯、二乙烯苯及苯乙烯的最低检出浓度分别为0．05、0．25、0．1、0．1、0．1、0．1、0．2、0．1μg·mL-1。结论：该法快速、灵敏、准确,适用于鸡骨草总黄酮碳苷提取物中大孔吸附树脂残留物的测定。     

中药废渣发酵生产微生物絮凝剂研究

本文采用常规的细菌分离纯化方法,从中药废渣中筛选出Psedudomonas trivialis 和Neurospora tetrasperma,利用中药废渣生产微生物絮凝剂的发酵条件及絮凝性能对其进行研究。结果表明,筛选出的菌种适宜在药渣中生长,且生产的絮凝剂能够对高岭土混悬溶液起到絮凝作用。在此基础上,考察了各因素对絮凝剂絮凝效果的影响,探讨不同药渣、菌种组合的最佳发酵条件。     

高效液相法测定陈皮药渣中橙皮苷含量

摘 要 目的:通过对陈皮药材及药渣中橙皮苷含量进行比较分析,为陈皮药渣的二次开发提供依据。方法: 色谱柱:Eclipse XDB- C₁₈(280 mm×4.6 mm, 5 μm)流动相：甲醇∶水∶冰醋酸（30∶66∶4）;流速：1.0 ml·min^-1;检测波长：283 nm。结果:橙皮苷与其它色谱峰分离良好。橙皮苷的线性范围在0.42～4.20 μg,r=0.999 7。陈皮药材的平均加样回收率为98.5%,RSD=2.12%(n=6);陈皮药渣的平均加样回收率为98.1%,RSD=2.35%(n=6)。结论:陈皮药渣中橙皮苷的提取量为陈皮药材中橙皮苷的提取量52%,表明陈皮药渣具有二次开发利用的价值。     

气相色谱-质谱法测定番茄酱中甲霜灵、苯霜灵、恶霜灵的残留量

目的：建立了番茄酱中甲霜灵、苯霜灵、恶霜灵残留量的气相色谱-质谱（GC—MS）测定方法。方法：番茄酱经乙腈提取盐析，样液浓缩后丙酮溶解定容。净化液用GC—MS测定，外标法定量。结果：4个添加水平的平均回收率在76．5％～103．2％之间，相对标准偏差在2．1％～7．8％之间。3种农药的最低检出限（LOD）分别为：甲霜灵、苯霜灵0．01mg／kg；恶霜灵0．05mg／kg。结论：该法简便、快速、灵敏、准确，各项技术指标均满足农药残留检测的要求。     

水产品中孔雀石绿及其代谢物残留量

〔目的〕建立一种简便、快速的检测水产品中孔雀石绿及其代谢物残留量的方法。〔方法〕采用乙腈一次萃取,标准系列加入阴性样品中同待检测样相同步骤同等条件下操作,待测样品萃取的不完全性误差可由与标准系列同等操作而基本抵消。优化了仪器检测条件,达到足够的灵敏度,样品提取液可不经浓缩直接进样测定,从而建立一种简便、快速的初筛方法。〔结果〕本方法加标回收率在68.4%～108%之间;相对标准偏差5.9%～10.8%,孔雀石绿及代谢物的定量限(LOQ)分别为0.50μg/Kg和0.20μg/Kg,检出限(LOD)分别为0.16μg/Kg和0.07μg/Kg。样品前处理到测定完成仅需30～40min。〔结论〕本方法相对于国标法节省了大量的时间和物力,适用于日常的大批量样品检测,相对于试剂盒和ELISA法更节约操作成本和操作更简便快速,但使用仪器较昂贵。     

Comparison of pesticide exposure from consumption of domestic and imported fruits and vegetables

Estimates of daily dietary human exposure to 18 common pesticides found in fruits and vegetables were developed from residue data obtained from the 2003 US Food and Drug Administration’s Regulatory Monitoring Program using probabilistic dietary exposure modeling. The differences between the exposures from domestic versus imported fruit and vegetable residues were compared. Of the 15 pesticides for which quantifiable residues were detected from both domestic and imported fruit and vegetable samples, domestic exposures were significantly higher for 11 pesticides while imported exposures were higher for the remaining four. The five pesticides showing the highest exposures all demonstrated greater domestic exposures than imported exposures. The mean daily exposure estimate for one pesticide, methamidophos, was above the reference dose for domestic fruits and vegetables while slightly below the reference dose for imported fruits and vegetables. Exposures to the other 17 pesticides were well below the established reference doses for domestic and imported fruits and vegetables. Exposure from pesticides in domestic foods exceeds exposure from imported foods and demonstrates that probabilistic modeling of dietary exposure provides more useful information concerning the relative risks of domestic and imported foods than that obtained from the traditional comparisons of residue detection frequency and violation rates.     

GC法测定三七三醇皂苷中8种大孔吸附树脂的残留物

目的 采用顶空气相色谱法同时测定三七三醇皂苷中8种大孔吸附树脂的残留物.方法 色谱柱为Agilent innowax 柱(30m×0.32 mm,0.5 μm),二甲亚砜为溶解介质,FID检测器,进样口温度140 ℃,检测器温度250℃,高纯氮作载气,程序升温(50℃保持20 min,再以6℃·min-1升至165℃,保持20 min).结果 各组分在所考察的浓度范围内均具有良好的线性,r为0.9903 ～0.9998,RSD为1.13％ ～6.99％,正己烷、环己烷、1,1,1-三氯乙烷、苯、甲苯、邻二甲苯、间二甲苯、对二甲苯的最低检出浓度分别为0.1389、0.3056、6.4980、0.5528、0.8282、1.9962、1.9500、2.6900 mg· kg-1.结论 所用方法快速、灵敏、准确,适用于三七三醇皂苷中大孔吸附树脂残留物的测定.     

Persistence of Acephate and Cypermethrin on Cotton Leaves,Cottonseed, Lint and Soil

Following foliar applications of combination formulation (cypermethrin 5% + acephate 45% DF) at 850 and 1,700 g ha(-1), resulting in active application of acephate at 382.5 and 765 g a.i. ha(-1) whereas active application of cypermethrin at 42.5 and 85 g a.i. ha(-1), the average initial deposits of acephate on cotton leaves were found to be 13.45 and 27.73 mg kg(-1), at single and double the doses of application, respectively. Residues of acephate declined below detectable level of 0.02 mg kg(-1) after 15 days of applications at application rates with t ((1/2)) values of 1.56 and 0.68 days, respectively. Similarly, the average initial deposits of cypermethrin were found to be 22.31 and 32.45 mg kg(-1), respectively. Cypermethrin residues reached below its detectable level of 0.02 mg kg(-1) after 21 days of its application at both the dosages of application. The half-life values for cypermethrin were observed to be 0.71 and 0.69 days, corresponding to single and double the dose of application, respectively. Interestingly, none of the samples of cottonseed, lint and soil showed presence of acephate or cypermethrin at the detection limit of 0.02 mg kg(-1) at first pick of the harvest time of the crop.