固相萃取-气相色谱-串联质谱法测定大蒜中19种有机磷农药残留量

建立了采用固相萃取(SPE)结合气相色谱-三重四级杆串联质谱(GC-MS/MS)测定大蒜中19种有机磷农药残留量的方法。采用V(乙酸)∶V(乙酸乙酯)=1∶99混合溶液提取,Carbon/NH2固相萃取小柱净化,在GC-MS/MS的多反应(MRM)模式下进行外标法定量。结果表明:在0.04~0.8 mg/L范围内,19种农药的色谱峰面积与其相应的质量浓度间均呈良好的线性关系;所有供试农药检测方法的定量限(LOQ)均低于0.01 mg/kg;在0.01~0.2 mg/kg添加水平下,19种农药的平均回收率在68.0%~130%之间,相对标准偏差(RSD)≤15.6%。该方法背景干扰少,灵敏度高,适合基质复杂的大蒜样品中有机磷农药残留量的检测。     

两种双发光镧系金属有机框架材料联用检测水中农药残留

传统单发射响应发光传感器因发射光波长单一易受环境因素干扰而灵敏度低,以及双/多元镧系共掺杂发光传感器由于体系内镧系元素之间的能量转移效率易受温度等因素影响而使得检测灵敏度与选择性低,本文提出联用两种双发光镧系金属有机框架材料(lanthanide metal-organic frameworks,Ln-MOFs)实现水...     

Initial pesticide residues in relation to vapour pressure

Field tests, in which several insecticides were applied at equal rates by ground sprayer to oats, rye and alfalfa, showed that residues 1 h after application were much lower for highly volatile compounds than for those of lower volatility. Varying the distance from spray release to target canopy from 10 to 40 cm did not significantly affect the deposits. Results indicate that applying insecticides with a vapour pressure greater than about 10^?4 mmHg (20°C) in aqueous media is very inefficient.     

固相萃取-气相色谱法测定水体中29种农药的残留量

建立了水体中29种农药的固相萃取-气相色谱检测方法。以Envi-18固相萃取小柱提取水样中的各种农药,上样体积为200 mL,洗脱溶剂为正己烷-丙酮(1∶1,体积比)。在添加水平为0.1、1.0和10 μg/L时,水样中29种农药的添加回收率为60%~111%,相对标准偏差(RSD)为1.2%~6.4%,方法的检出限(LOD)为5~50 ng/L。所建立方法准确、灵敏、快速,符合水体中多种农药残留检测分析的要求,且对水体中低浓度残留农药的检测效果较好。     

Foliar pesticide residues in relation to worker re-entry

Residues were determined at 8-h intervals during the 48 h after application of endosulfan, leptophos, methamidophos, methomyl and mevinphos to head lettuce; of endosulfan, methamidophos and methomyl to cauliflower; and of parathion to onions and carrots. Residues of phosalone and parathion were measured on apple leaves 0, 1, 2, 4, 8 and 16 days after application. In addition, the portion of the residue on apple leaves that could be dislodged was measured, as well as the residues on gloves used to handle the apple foliage. There were large differences in the rates of disappearance of the insecticides, differences that must be known in determining safe re-entry periods for workers.     

分散固相萃取-超高效液相色谱-串联质谱法检测大豆中6种典型农药残留

本研究建立了分散固相萃取-超高效液相色谱-串联质谱法同时检测大豆中灭草松、三氟羧草醚、氯虫苯甲酰胺、甲氨基阿维菌素苯甲酸盐、吡唑醚菌酯、精喹禾灵及其代谢物喹禾灵酸的多残留分析方法,为监测大豆生产中的农药应用风险提供方法。该方法具有简单、快捷、准确、灵敏度高的特点。样品经1%甲酸-乙腈振荡提取后,分散固相萃取净化,流动相为甲酸铵-水溶液(含0.01% 甲酸)和甲酸铵-甲醇溶液(含0.01% 甲酸),采用苯基色谱柱进行分离,基质匹配标准曲线外标法定量分析。结果表明:目标农药及代谢物在0.001~1 mg/kg添加水平下平均回收率为78.1%~116.0%,相对标准偏差(RSD)为1.6%~20.5%,该方法在0.001~1 mg/kg范围内线性良好(R2≥0.991 1),定量限(LOQ)可达0.001 mg/kg。基于此方法对内蒙古产区的大豆样品进行测定,发现大豆中灭草松、氯虫苯甲酰胺、吡唑醚菌酯有检出,残留量在<0.001~0.024 mg/kg之间,喹禾灵酸、三氟羧草醚、甲氨基阿维菌素苯甲酸盐残留量均<0.002 mg/kg。采集的大豆样品中6种目标农药残留量均符合我国农药最大残留限量标准安全要求。     

固相萃取-气相色谱-三重四极杆串联质谱法测定茶叶中45种有机磷农药残留

采用气相色谱-三重四极杆串联质谱(GC-MS/MS)技术建立了茶叶中45种有机磷农药残留的检测方法。茶叶样品加水浸泡后采用乙腈提取,经TPT固相萃取柱净化,用V (乙腈) : V (甲苯) ＝ 3 : 1混合溶液洗脱,采用GC-MS/MS检测,基质匹配标准溶液外标法定量;分析了加水对茶叶中有机磷类农药提取效率的影响。结果表明:45种有机磷类农药在各自质量浓度范围内线性关系良好,相关系数均大于0.993。方法检出限为0.001~0.01 mg/kg,定量限为0.002~0.02 mg/kg。在0.05、0.5和5 mg/kg 3个添加水平下,45种农药平均回收率在71%~102%之间,相对标准偏差均小于9.4%。     

Variability of pesticide residues in crop units

The results of 89 new field trials and 11 supervised trials were considered, together with 91 sets of residue data evaluated earlier. The datasets consisted of 22,643 valid residue data. As all variability factors calculated from individual sample sets are affected by the uncertainties of sampling and analysis, the average of the P(0.975)/R(ave) (97.5th percentile of the residue population divided by the average residues in the lot) values gives the best estimate for the variability factor. The Harrell-Davis (H-D) method gave an average value of 2.89 for the variability factor for all samples, while the average variability factors obtained from samples derived from the new field and supervised trials were 2.8 and 2.7 with the IUPAC and H-D methods respectively. The number of residue values below the LOQ in a sample set significantly affects the observed variability factors. It was found that datasets containing over 20% non-quantifiable residues might not reflect the true variability of the residues. Mixing of treated and non-treated commodities may significantly increase the apparent variability. Consequently, only datasets of known origin and consisting of well-quantifiable residues should be used for estimation of the variability factor. Samples taken from marketed lots may not represent a single lot, and thus they have limited value in estimating the variability factor. The large number of residue data confirms the applicability of the default variability factor of 3 adopted by the FAO/WHO for deterministic estimation of the acute intake of pesticide residues.     

Leaf surfaces and the bioavailability of pesticide residues

Laboratory bioassays were carried out to determine the toxicity to Folsomia candida Willem (Collembola: Isotomidae) of residues of a pyrethroid insecticide, deltamethrin, and an organophosphorus insecticide, dimethoate, on different leaf surfaces. The test leaves included a range of species and leaves of different ages. Dose-response relationships were estimated for F candida walking over the various treated leaf substrates. Probit analysis was used to estimate the means and standard deviations of the associated tolerance distributions expressed as gAIha-1. Parallelism tests were undertaken to compare the susceptibilities of F candida to the two compounds applied to the different leaf surfaces. On deltamethrin-treated leaf surfaces, the LD50 values for F candida varied from 6.36 to 77.14 gAIha-1. F candida was least susceptible to deltamethrin residues when applied to leaves of dwarf bean (Phaseolus vulgarus L) and the highest susceptibility was observed following application to leaves of seedlings of barley (Hordeum vulgare L). In contrast, the LD50 values observed for dimethoate treatments did not differ significantly between leaf types, ranging from 1.35 to 8.69 gAIha-1. The laboratory data on susceptibility of F candida on different leaf types for different pesticides can be used to investigate the role of leaf surface properties in modifying the toxicity of applied pesticides to exposed invertebrates.     

武威平原区饮用水源地土壤六六六和滴滴涕残留特征研究

以石羊河流域武威平原区集中式饮用水源保护区土壤为研究对象采用现场采样及室内测试的方法对其有机氯农药六六六(HCHS)和滴滴涕(DDTs)的残留水平、组成特征进行研究探讨污染物的潜在来源和生态风险。结果表明,该区域DDTs未检出,72.7%的样品检测出不同浓度水平的HCHs(0.134~0.616μg·kg~(-1)),平均为0.323±0.16μg·kg~(-1);所有样品的HCHS和DDTs均远低于国家土壤环境质量一级标准限值(50μg·kg~(-1)),污染程度很低,生态风险小。HCHs的4种异构体中,β-HCH和γ-HCH的检出率分别为27.3%和72.7%,平均浓度分别为0.326±0.107μg·kg~(-1)和0.201±0.089μg·kg~(-1),α-HCH和δ-HCH均未检出。该区域HCHs与土壤有机质之间几乎没有相关性,HCHs主要来源于大气的干湿沉降或传输。     

新型农药残留快速检测技术研究进展

农药残留检测关乎食品安全和人类健康问题。传统农药残留检测通常选择色谱法或色谱-质谱联用法等,具有准确、稳定等优势,但通常需要昂贵而复杂的大型仪器,样品前处理过程费时费力,对操作人员要求高。为了克服这些缺陷,一系列农药快速检测技术相继被开发出来。文章介绍了可用于农药残留快速检测的主要技术,包括生物传感器 (酶传感器、免疫传感器、适配体传感器、细胞传感器)、光谱技术 (近红外光谱、太赫兹时域光谱、拉曼光谱等) 与微流控技术,重点介绍了这些技术的原理、特点与最新研究进展,分析了目前农药快速检测技术存在的问题与未来的发展前景。     

分子印迹-基质固相分散萃取-高效液相色谱法测定土壤中4种硫代磷酸酯类农药残留量

建立了一种高效、选择性强的分子印迹-基质固相分散萃取结合高效液相色谱测定土壤中4种硫代磷酸酯类农药(毒死蜱、甲基立枯磷、甲基毒死蜱、甲基对硫磷)残留量的方法;并以甲基立枯磷为模板分子,以甲基丙烯酸(MAA)为功能单体,且n(模板分子)∶n(功能单体)=1∶4,以乙二醇二甲基丙烯酸酯(EDMA)为交联剂,以偶氮二异丁腈为引发剂,采用沉淀印迹聚合方法,合成了甲基立枯磷高分子印迹聚合微球(MIPs);以MIPs作为土壤样品提取液的基质固相分散吸附剂,采用HPLC检测处理后的样品,流动相为V(乙睛)∶V(0.1%乙酸水溶液)=3∶1,流速0.8 m L/min,进样量20μL,检测波长210 nm,采用Agilent Eclipse XDB-C8色谱柱(150 mm×4.6 mm,5μm),柱温25℃。结果显示:MIPs对甲基立枯磷有特异性吸附,对其结构相似物毒死蜱、甲基对硫磷和甲基毒死蜱也具有一定的吸附性能;在0.01~5.0 mg/kg范围内,各药剂的质量浓度与相应的峰面积间呈良好的线性关系,相关系数r为0.997 5~0.999 8;4种硫代磷酸酯类有机磷杀虫剂的检出限(LOD)为0.452~1.226μg/kg;添加回收率为76%~96%,相对标准偏差(RSD)为2.8%~7.3%。该方法可用于土壤中硫代磷酸酯类有机磷杀虫剂残留量的测定。     

农药残留研究进展与展望

农药残留是农药应用后的必然现象。农药残留引起的安全问题已经引起全社会的高度关注。本文从农药残留分析方法、农药环境行为、加工农产品中农药残留变化、我国农药残留标准制定等四个方面简要综述近年来农药残留研究的基本状况及发展趋势,以期为农药残留的深入研究提供参考和借鉴。     

2008年山西蔬菜中农药残留问题分析

通过对山西省2008年蔬菜中农药残留监测数据的分析,找出了蔬菜中农药残留存在的问题和原因,并有针对性的提出了蔬菜中农药残留防治的重点措施.     

化学计量学在农药残留分析中的应用与进展

本文对近几年来化学计量学方法在农药残留分析测试中的应用进行了评述．指出了化学计量学在农药残留分析中的重要性及应用前景。     

臭氧水对黄瓜和青菜中6种有机磷农药残留的去除效果

考察了臭氧水浸泡处理对黄瓜和青菜上6种有机磷类农药残留的去除效果。发现臭氧水浸泡的去除效果优于自来水处理,在通臭氧30 min后,其对青菜和黄瓜中乙酰甲胺磷、二嗪磷、马拉硫磷、毒死蜱、喹硫磷和三唑磷的总去除率分别为26.4%~65.2%和22.7%~75.4%,净去除率分别为6.8%~17.3%和4.4%~45.4%。对6种农药在臭氧水中降解速率的研究表明,臭氧处理对残留农药的去除效果与果蔬种类、处理时间及残留物种类有关。     

加工过程对大米中农药残留影响的荟萃分析

采用荟萃分析方法探讨加工过程对大米中农药残留的影响,获得的响应比可为膳食风险评估提供加工因子。通过对多个数据库进行文献检索、数据采集、荟萃分析计算,以获得不同加工方法对大米中农药残留影响的响应比及相关参数。结果表明:单一加工方法中,脱壳、碾磨、抛光、浸泡、清洗1次、清洗2次、清洗3次、普通蒸煮和高压蒸煮的响应比分别为0.376、0.310、0.212、0.518、0.450、0.338、0.162、0.356和0.144,其中脱壳、碾磨和抛光的响应比均小于0.4,可有效降低大米中的农药残留量;随着清洗次数增加,清洗对农药残留量的去除效果增强;高压蒸煮对降低农药残留量的效果最佳;而浸泡效果较差。组合加工方法的响应比与单一加工方法响应比的乘积基本一致。所获得的响应比作为加工因子用于食品安全风险评估中,可提升大米风险评估结果的准确性,并可为大米中农药最大残留限量标准的制定以及居民安全膳食引导提供参考。     

浙江省猕猴桃主产区果实农药残留水平与评价

以无公害落叶浆果类果品标准为评价标准,对浙江省猕猴桃主产区180个猕猴桃样品中农药残留情况进行了分析与评价.结果表明:浙江省猕猴桃农药品种检出率71.4％,样品农药检出率52.2％.在所检测的7种农药中,敌敌畏、乐果2种有机磷农药均未检出,4种拟除虫菊酯类农药均有不同程度的检出,检出率依次为:氯氰菊酯25.6％,百菌清17.2％,三唑酮12.2％,溴氰菊酯0.56％,杀菌剂多菌灵检出率26.7％,有机磷类农药和拟除虫菊酯类农药来发现超标现象,多菌灵存在超标现象,超标率2.22％.不同产地和取样场所果实中农药残留检出率存在一定差异.经单项农药污染指数和综合农药污染指数评价发现,浙江省猕猴桃未受到农药污染,品质基本安全.     

Contribution of non-agricultural pesticides to pesticide load in surface water

Two small creeks, tributaries of the River Ruhr near Schwerte, Federal Republic of Germany, were investigated to reveal the regional agricultural and non-agricultural sources of pesticide inputs and the main pathways to surface water. In addition, the receiving water was monitored for pesticides. The watersheds are situated at the northern margin of the Rhenian Schiefergebirge, a highland landscape in North-Rhine-Westphalia. Solid carboniferous shale is covered by a shallow layer of quaternary unconsolidated rock (porous aquifer thickness <5 m). Occurrence of herbicides such as chlortoluron, isoproturon and terbuthylazine in surface water could be due to their broad agricultural application in regional dominant crops, such as barley, wheat and maize. Occurrence of diuron and glyphosate results from their use in residential settlements and industrial areas as well as from weed control on railway tracks. Atrazine concentrations up to 0.8 microg litre(-1) indicated recent use of this herbicide, which has been banned since 1991, and was also the result of non-agricultural applications. Pathways for pesticide input to the receiving waters were related to both surface run-off and underground passage. Two-thirds of the observed diuron load in the surface water resulted from an input by run-off. This was expected as a result of total herbicide application targets to sealed surfaces infringing current regulations and recommendations. Diuron load varied between 0.6 and 1.2% of the estimated amount applied annually in the investigated catchments. Non-agricultural pesticide use contributed more than two-thirds of the whole observed pesticide load in the tributaries and at least one-third in the River Ruhr.