气相色谱法测定水果中灭多威残留量

本文用气相色谱法测定水果中灭多威残留量,采用带硫滤光片的光焰光度检测器检测,灭多威的检测限为0.2ng,在水果中的最低捡出浓度为0.05mg/kg,加标浓应为0.10——5.0mg/kg时,平均回收率为89.3％——104.7％,高、中、低三种浓度的变异系数均小于5％。     

Determination of Organochlorine Pesticide Residues in Freshwater Fish Species in Punjab,India

The levels of organochlorine pesticides residues were determined in five freshwater fish species in Punjab State, India. These species were selected in view of their importance to local human fish consumer. DDTs were the predominant organochlorine contaminants in all species with pp DDT and pp DDE as the main pollutants. Other organochlorines, such as HCH isomers and dieldrin were also found at lower levels in fish species. The α-HCH was the dominant isomer of HCH in all fish species followed by γ-, β- and δ-HCH. The residues of aldrin, chlordane, heptachlor and endosulphan were not detected in any fish sample. The levels of organochlorines detected in present study were below the tolerance limits recommended at National and International standards.     

Determination of Pesticide Residue in Soil,Water and Grain from IPM and Non-IPM Field Trials of Rice

Soil, water and rice grain samples from field trials conducted under the IPM and non-IPM modules in Kaithal (Haryana) region were analyzed for pendimethalin, atrazine, lindane and chlorpyriphos, and in Dehradun (Uttarakhand) region, samples were analyzed for carbendazim only. The pesticide residues were found below the detectable limit in the soil and water samples of the Kaithal region. From Dehradun region the residues of carbendazim in rice grains were detected at 0.001 mg/kg level, and in soil they were in the range of 0.03-0.001 mg/kg. The insecticides applied in IPM as well as non-IPM trials in both regions were observed to be below the prescribed maximum residue level.     

Exposure of babies to C15-C45 mineral paraffins from human milk and breast salves

Mineral paraffins widely occur in foods, but are also ingredients of body lotions, lip sticks, and breast salves. In this study it is shown that mineral paraffins are detectable in human milk. Thirty three human milk samples were found to contain mineral C(15)-C(45) paraffins at a mean concentration of 95+/-215mg/kg fat and a maximum of 1300mg/kg. The mineral paraffins found in human milk had average molecular weights between C(23) and C(33), and often more than half of the paraffins were below C(25).Beside exposure of babies via human milk, the intake by direct licking off salves (in the worst case consisting of vaseline) from the breast of their nursing mothers may be much higher. In a worst case situation, daily intake from breast care products by babies is estimated to reach 40mg/kg bw. Many compositions do not comply with the specifications and a temporary group ADI of 0-4mg/kg bw established by the SCF.This possible exposure of babies either calls for a toxicological re-evaluation of the mineral paraffins or for measures ensuring that exposure of babies is reduced.     

固相萃取-毛细管气相色谱法测定莪术中15种有机氯农药的残留量

目的用固相萃取-毛细管气相色谱分析方法测定莪术中15种有机氯农药残留量。方法样品以混合溶剂超声提取、Florisil固相萃取小柱净化处理后,采用DB-1701毛细管气相色谱柱分离样品,电子捕获检测器检测。内标法定量,计算有机氯农药的残留量。结果15种农药在5~500μg.L-1范围内具有良好的线性关系,相关系数均大于0.995。15种农药3个不同浓度的平均回收率为83.1%~110.6%,RSD%为3.4%~14.8%。最小检测量为0.08~1.5μg.L-1。被测样品中均含有不同程度的有机氯农药。结论本法简便、灵敏、准确、重现性好,可用于中药材中有机氯类农药的残留量测定。     

顶空气相色谱-质谱法测定药品包装材料中40种有机溶剂残留量

目的:建立测定药品包装材料中正辛烷、丙酮、辛烯、乙酸乙酯等40种有机溶剂残留量的方法。方法:采用顶空气相色谱-质谱法,色谱条件为Agilent VF-WAX MS毛细管气相色谱柱(60 m×0.32 mm, 1.00μm),柱温为程序升温(起始温度45℃,保持5 min,以5℃·min^-1升温至150℃,再以20℃·min^-1升温至220℃,保持4 min),进样口温度：220℃;载气为高纯氦气,流速为1.0 mL·min^-1,分流比为10∶1;进样体积为1 mL;质谱条件为电子轰击离子源(EI),轰击电压70 eV;离子源温度为280℃,接口温度250℃;扫描方式：定性SCAN(质量数范围29～650),定量SIM。结果:所建立的方法呈良好的线性关系,相关系数r为0.995 3～0.999 6,各有机溶剂平均回收率均在94.25%～107.46%范围内,RSD为0.06%～1.92%。药用复合膜、药用复合硬片、药用铝箔的有机溶剂残留量检测结果分别为0.011～1.688、2.631～24.586、0.084～18.66...     

Persistence of Ethion Residues on Cucumber, Cucumis sativus (Linn.) using Gas Chromatography with Nitrogen Phosphorus Detector

Residues of ethion were estimated in cucumber by gas liquid chromatography following three applications of the insecticide at 375 and 750 g a.i ha⁻¹. The average initial deposits of ethion on cucumber fruits were found to be 2.40 and 4.97 mg kg⁻¹ at single and double dosages, respectively. Residues of ethion dissipated below the maximum residue limit (MRL) of 0.5 mg kg⁻¹ in 7 days. Half-life (T_1/2) for degradation of ethion on cucumber was observed to be 2.92 days at recommended dosage. A waiting period of 7 days is suggested for safe consumption of cucumber.     

地龙药材中六溴环十二烷三种异构体残留量的测定和风险评估

目的：建立一种高效液相色谱-串联质谱法（HPLC-MS/MS）同时测定地龙药材中新污染物六溴环十二烷（HBCDs）3种异构体残留量,并评估其健康风险。方法：取地龙药材细粉,加入13C12-α-HBCD、13C12-β-HBCD和13C12-γ-HBCD内标溶液,经超声提取复合硅胶柱净化后,采用液相色谱串联质谱多反应监测,内标法定量。结果：HBCDs 3种立体异构体线性关系良好（r2 ＞ 0.999）,检出限和定量限分别约为2和6 pg·g-1,平均回收率为97% ~ 120%,RSD为7.1% ~ 7.4%,精密度为1.1% ~ 7.4%（n = 6）。78批地龙药材中有73批检出HBCDs,检出率为94%,其中以α-HBCD的含量最高。使用欧洲食品安全局建议的暴露边界值法对地龙药材中HBCDs的风险评估表明,经地龙药材摄入的HBCDs引起健康问题的风险较小。结论：建立的地龙药材中新污染物HBCDs残留量的液相色谱-串联质谱测定法灵敏、准确、可靠,适用于地龙药材中HBCDs残留量的定量分析,可为中药材外源性新污染物的安全监测提供科学参考。     

Cumulative risk assessment of pesticide residues in food

There is increasing need to address the potential risks of combined exposures to multiple residues from pesticides in the diet. The available evidence suggests that the main concern is from dose addition of those compounds that act by the same mode of action. The possibility of synergy needs to be addressed on a case-by-case basis, where there is a biologically plausible hypothesis that it may occur at the levels of residues occurring in the diet. Cumulative risk assessment is a resource-intense activity and hence a tiered approach to both toxicological evaluation and intake estimation is recommended, and the European Food Safety Authority (EFSA) has recently published such a proposal. Where assessments have already been undertaken by some other authority, full advantage should be taken of these, subject of course to considerations of quality and relevance. Inclusion of compounds in a cumulative assessment group (CAG) should be based on defined criteria, which allow for refinement in a tiered approach. These criteria should include chemical structure, mechanism of pesticidal action, target organ and toxic mode of action. A number of methods are available for cumulating toxicity. These are all inter-related, but some are mathematically more complex than others. The most useful methods, in increasing levels of complexity and refinement, are the hazard index, the reference point index, the Relative Potency Factor method and physiologically based toxicokinetic modelling, although this last method would only be considered should a highly refined assessment be necessary. Four possible exposure scenarios are of relevance for cumulative risk assessment, acute and chronic exposure in the context of maximum residue level (MRL)-setting, and in relation to exposures from the actual use patterns, respectively. Each can be addressed either deterministically or probabilistically. Strategies for dealing with residues below the limit of detection, limit of quantification or limit of reporting need to be agreed. A number of probabilistic models are available, but some of there are geographically constrained due to the underlying datasets used in their construction. Guidance on probabilistic modelling needs to be finalised. Cumulative risk assessments have been performed in a number of countries, on organophosphate insecticides alone (USA) or together with carbamates (UK, DK, NL), triazines, chloroacetanilides, carbamates alone (USA), and all pesticides (DE). All identifiable assumptions and uncertainties should be tabulated and evaluated, at least qualitatively. Those likely to have a major impact on the outcome of the assessment should be examined quantitatively. In cumulative risk assessment, it is necessary, as in other risk assessments, for risk managers to consider what level of risk would be considered "acceptable", for example what percentile of the population should be below the reference value. Criteria for prioritising CAGs for cumulative risk assessment include frequency of detection in monitoring programmes, high usage, high exposure relative to the reference value, large number of compounds (e.g. five or more) in a group.     

肉桂中有机氯农药残留量的含量测定

目的:对中药肉桂进行有机氯农药的残留量测定。方法:采用气相色谱法对六六六(BHC)4种异构体、滴滴涕(DDT)4种异构体、五氯硝基苯(PCNB)及六氯化苯(HCB)进行测定。结果:所测样品中BHC≤0.01mg·kg-1,DDT≤0.01mg·kg-1,PCNB≤0.01mg·kg-1,HCB≤0.01mg·kg-1。结论:所测肉桂中农药残留量低于国家相关的规定限量。