MSPD和SPE两种方法前处理苹果(汁)中棒曲霉素的比较研究

建立并比较了分别采用基质固相分散(MSPD)和氰基柱固相萃取(SPE)两种前处理技术,高效液相色谱(HPLC)检测苹果(汁)中棒曲霉素的方法.两种方法的回收率和变异系数均满足检测要求.结果表明,建立的两种方法简便、快速、准确,各有优缺点,不同的样品中棒曲霉素的前处理应采用不同的方法.     

基质固相分散在食品安全分析中的应用

MSPD作为一种崭新的SPE技术，对半固体、固体样品中目标成分分析具有独一无二的特性，国外已将此法广泛的应用于食品中药物残留、污染物和有害成分分析。本文介绍了MSPD在食品安全分析中应用，并且讨论了MSPD在样品处理中的理论和实践。     

基于QuEChERS与UPLC-Triple-TOF-MS相结合的水稻中溴氰菊酯的检测

对Qu ECh ERS前处理与超高效液相色谱-三重四级杆飞行时间串联质谱(UPLC-Triple-TOFMS)相结合的方法检测水稻中溴氰菊酯残留的应用进行了探索。检测发现溴氰菊酯在(0.01~5.0)mg/L浓度范围内呈良好的线性关系,线性相关系数为0.9999,回收率在90.14%~99.86%范围之间,方法的相对标准偏差(RSD)小于5%。该前处理方法具有回收率高、分析范围广、精确度和准确度高、操作简便且分析速度快、污染小等优点。并比较了该法与气相色谱-质谱法(GC-MS)检测溴氰菊酯残留结果,结果显示超高效液相色谱-三重四级杆飞行时间串联质谱联法在检测分析水稻中溴氰菊酯农药残留具有一定的优势。     

样品前处理技术结合高效液相色谱技术在食品安全检验中的应用

本文简介了高效液相色谱技术以及样品前处理技术,并通过固相微萃取结合高效液相色谱技术、浊点萃取结合高效液相色谱技术分别对水体中的农药残留、饮料中的赤藓红含量进行测定,阐释食品安全检验中高效液相色谱以及样品前处理技术的应用。     

高效液相色谱技术在食品检测中的应用

食品检测是食品安全控制的重要基础与条件,高效液相色谱技术是一种有效的食品安全检测方法,其最大的优势在于能够同时对食物中的复杂成分进行检测,节省了大量的时间和费用,提高了食品的检测质量与水平。本文就高效液相色谱技术在食品检测中的应用进行了探讨,以期为进一步提高食品检测的质量提供参考。     

高效液相色谱法同时测定水产品中氨基甲酸酯类的残留

建立固相萃取-高效液相色谱法测定水产品中5种氨基甲酸酯的残留量。以丙酮/二氯甲烷提取残留物,经氨基固相萃取柱净化,样品分析时根据5种氨基甲酸酯特定的最大吸收波长通过使用变波长进行测定。结果表明,与传统的液相色谱-紫外检测方法相比,该方法具有更好的净化效果,且方法回收率在62.40%～90.25%;降低最低检出限,涕灭威、速灭威、克百威、甲萘威、异丙威的最低检出限分别为1.47,1.15,0.74,2.56,3.25μg/kg;适合于水产品中5种氨基甲酸酯类的同时分析测定,具有较好的实验室应用前景。     

动物源性食品中喹诺酮类残留前处理及分析方法的研究进展

喹诺酮类兽药残留是目前重要的动物源性食品安全问题之一,检测食物基质中痕量兽药残留依赖于有效的前处理方法和精密的分析仪器。本文阐述了喹诺酮类兽药的研究背景和现状,并对国内外食品中喹诺酮类兽药残留的液液萃取(Liquid-Liquid Extraction,LLE)、固相萃取(Solid-Phase Extraction,SPE)、基质辅助固相分散萃取(Matrix Solid-Phase Dispersion,MSPD)、Qu ECHERs(Quick,Easy,Cheap,Effective,Rugged,Safe,Qu ECHERs)、超临界流体萃取(Supercritical Fluid Extraction,SFE)和免疫亲和色谱(Immunoaffinity Chromatography,IAC)等前处理方法及液相色谱质谱法、液相色谱法、毛细管电泳分析方法及免疫分析测定法等检测方法进行了综述,拟为动物源性食品中喹诺酮类药物的残留监控提供理论参考,综述指出SPE和Qu ECHERs为最有前景的前处理方法,而质谱技术的发展和仪器的小型化为检测仪器的发展趋势。     

高效液相色谱法在水质砷检测中的应用研究

高效液相色谱法是一种准确、灵敏、可靠的水质砷检测方法,具有广阔的应用前景。本文探讨了高效液相色谱法在水质砷检测中的应用,介绍了高效液相色谱法的基本原理和操作流程,讨论了高效液相色谱法在水质砷检测中的具体应用,包括样品前处理技术、色谱条件优化策略、检测参数的确定与验证以及实际水样中砷的测定过程,以期为业内检测人员提供理论参考。     

肉类产品中兽药残留的检测方法概述

本文就肉类产品中兽药残留的检测技术进行了论述,并着重论述了近年来发展起来的新技术,如前处理技术中的SPE、MSPD、SFE、IAC和检测技术中的CharmⅡ检测法、ELISA、生物传感器测定法、CZE等.     

基质分散固相萃取-高效液相色谱检测黄瓜中涕灭威和异丙威的农药残留

采用Florisil硅土为吸附剂的基质固相分散萃取-高效液相色谱法检测黄瓜中涕灭威和异丙威农药残留.对洗脱剂的种类和用量以及样品与吸附剂填料比进行实验,建立并优化了检测方法.该方法对黄瓜样品中的涕灭威和异丙威农药残留的回收率在87.12％ ～90.60％之间,方法的最低检出限为0.099～0.82μg/mL.该方法具有简单、快速、重现性好、灵敏度高等特点,满足蔬菜中氨基甲酸酯农药残留量的检测要求.     

异丙威单克隆抗体的制备及鉴定

异丙威是我国农业生产中常见的杀虫剂,在果蔬、粮食和烟草等中都有广泛应用,然而这类农药也具有较强生物毒性。为了制备异丙威单克隆抗体,以实现对农药异丙威药物的快速检测。本文以2-异丙基苯酚等为原料,合成异丙威半抗原及人工抗原,并通过免疫小鼠、细胞融合、克隆、筛选获得单克隆抗体细胞株,经腹水诱导法及辛酸-硫酸铵沉淀法制得异丙威单克隆抗体,通过间接竞争ELISA法对抗体的特异性进行鉴定。结果表明,制备的异丙威单克隆抗体检测范围为1.88~82.80 ng/m L,抗体的IC50为11.70ng/m L,最低检测限为0.54 ng/m L,抗体与克百威、西维因、涕灭威、灭多威、2-异丙基苯酚5种异丙威结构类似物均无明显交叉反应,具有高特异性,能够满足农产品中异丙威残留检测的要求。异丙威单克隆抗体的制备为异丙威快速检测产品的开发奠定了基础。     

气相色谱法测定水果和蔬菜中异丙威、嘧霉胺、抑霉唑残留量

介绍了应用配有FTD/NPD/检测器的气相色谱仪测定水果和蔬菜中异丙威、嘧霉胺、抑霉唑残留量的方法。样品用乙酸乙酯提取,经过硅胶柱净化,旋蒸定容后上机。以GC-FTD(NPD)测定,外标法定量。嘧霉胺、异丙威、抑霉唑分别在一定范围内,质量浓度与峰高(峰面积)呈良好的线性关系。方法准确,重现性、精密度好,杂质干扰少。方法检出限嘧霉胺0.005mg/kg,异丙威0.01mg/kg,抑霉唑0.01mg/kg。     

一种异丙威胶体金免疫快速检测试纸条的研制

农产品的农药残留检测方法较多，异丙威作为速效性农药，应用较为广泛，但是检测异丙威的快速检测方法极少。该研究通过制备异丙威半抗原，研制出一种能够检测蔬菜、水果中异丙威的胶体金免疫层析试纸条。结果表明，该试纸条对蔬菜、水果等农产品中异丙威的最低检出限为10 μg/kg，检测时间仅为15 min，假阳性率和假阴性率均为0。与甲草胺、亚胺菌、乙霉威和异丁草胺等药物无交叉反应，技术指标均符合《农残办技术材料要求及审查程序》要求。该试纸条检测快速、便捷，能够应用到基层实验室的大批量样本检测，具有实际意义。     

Insecticidal properties of eugenol, isoeugenol and methyleugenol and their effects on nutrition of Sitophilus zeamais Motsch. (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Eugenol, isoeugenol and methyleugenol showed similar contact toxicity to Sitophilus zeamais (LD₅₀ values approximately 30 μg/mg insect). For Tribolium castaneum, the order of potency of these chemicals compared by the LD₅₀ level was isoeugenol>eugenol>methyleugenol. Furthermore, S. zeamais was generally more susceptible than T. castaneum to these three compounds except for isoeugenol based on the LD₅₀ level. When sublethal doses (doses that produce no appreciable mortality) of eugenol, isoeugenol and methyleugenol were topically applied to adults of either species of beetles pre-treated with deltamethrin, the toxicity of deltamethrin was enhanced. A flour disc bioassay using no-choice tests was employed to assess, in terms of food consumption and growth rate, the susceptibility of S. zeamais and T. castaneum to media treated with eugenol, isoeugenol, and methyleugenol. Only eugenol significantly (P<0.05) reduced food consumption (RCR) in the adults of S. zeamais at a concentration of 13.2 mg/g food. However, it reduced the growth rate (RGR), food consumption and food utilisation (ECI) in adults and larvae of T. castaneum at concentrations of 35 and 99 mg/g food, respectively. Isoeugenol reduced the RGR and RCR in S. zeamais adults and T. castaneum adults and larvae, in a concentration-dependent manner, but only reduced ECI in the adults of T. castaneum at the concentration of 76 mg/g food. In comparison, methyleugenol reduced the RGR and RCR in the three groups of insects, and the ECI of S. zeamais adults and T. castaneum larvae.     

氨基甲酸酯类农药半抗原的设计与改造

本研究设计了一种针对氨基甲酸酯类农药半抗原的通用改造,制备了涕灭威和异丙威两种人工半抗原。通过分子模拟手段和制备鼠源多克隆抗体对半抗原改造效果进行评价。结果表明,最终涕灭威抗体效价为5.84×105,对涕灭威的IC₅₀为0.225 μg/mL,对涕灭威半抗原的交叉反应率为107.14%;异丙威抗体效价为4.1×105,对异丙威的IC₅₀为0.4 μg/mL,对异丙威半抗原的交叉反应率为105.26%。经该通用改造后的半抗原可以代替目标药物用于免疫分析方法的建立。     

香料烟中“溴氰菊酯”的残留降解研究

为了评价“溴氰菊酯”在香料烟中的残留降解行为,进行了连续2年“溴氰菊酯”在香料烟中的残留田间试验.检测结果表明:①2.5％“溴氰菊酯”乳油在香料烟叶中的降解符合一级动力学降解模式,其半衰期为5.80 ～ 6.19 d;②施药后15 d残留量在0.0128 mg· kg-1以下,降解率达95％以上;③按600 mL· hm-2喷施2次和3次2.5％“溴氰菊酯”乳油,15 d后采收,香料烟鲜烟叶中的残留量为＜0.01～ 0.4703 mg· kg -1;④2年的气候条件虽然有差异,但“溴氰菊酯”在香料烟中的残留降解行为基本一致.在香料烟的生长过程中,按照推荐用量,在15 d安全间隔期以上,连续3次施用2.5％“溴氰菊酯”乳油,“溴氰菊酯”的残留量不超过0.05 mg· kg-1.     

Residual efficacy of deltamethrin and β-cyfluthrin against Trogoderma variabile and Trogoderma inclusum (Coleoptera: Dermestidae)

Trogroderma variabile Ballion, warehouse beetle, and Trogoderma inclusum LeConte, larger cabinet beetle, are dermestid pests of stored products. A series of laboratory bioassays were conducted to evaluate residual toxicity of the pyrethroids deltamethrin and β-cyfluthrin, applied on a concrete surface substrate for control of adults and larvae of both species, to provide initial baseline susceptibility data for dermestids. Commercial formulations were applied at calculated deposition rates of 8, 16, and 24 mg active ingredient [AI] per m² for deltamethrin and 10 and 20 mg active ingredient [AI] per m² for β-cyfluthrin. Ten adults or larvae of either species were introduced to individual untreated and treated arenas at 0, 0.5, 1, 2, and 3 mo post-treatment. Adult mortality was evaluated after 4 d of exposure with no food provided, and larval mortality was assessed 30 d after exposure with provision of food. Adult mortality of both species exposed to both insecticides ranged from 72.4 ± 6.9 to 100% depending on exposure interval. Larval mortality ranged from 18.3 ± 5.4 to 96.7 ± 2.1% on arenas treated with deltamethrin, and was significantly lower than adult mortality (P < 0.001) at bioassays conducted at 2 and 3 mo post-treatment for both species at all three rates. Larval mortality on arenas treated with β-cyfluthrin ranged from 20.0 ± 4.5 to 71.7 ± 4.8%, and was always lower (P < 0.001) at all exposure times at both rates for both species. There were only 4 out of a possible 20 comparisons with a significant difference (P < 0.05) between the three rates of deltamethrin and no occasions where there is a significant difference in mortality between the two rates of β-cyfluthrin. There were three occasions where mortality of T. inclusum adults or larvae was greater than T. variabile, and one occasion with the reverse, for exposures with deltamethrin. Results show larvae of both species were more tolerant than adults of both species, and larvae could be used as an indicator stage for future studies insecticidal susceptibility of Dermestids.     

A field experiment to determine the relative importance of prey and water as sources of As, Cd, Co, Cu, Pb, and Zn for the aquatic invertebrate Sialis velata

We measured the relative importance of water and food as sources of the trace elements As, Cd, Co, Cu, Pb, and Zn for larvae of the benthic insect Sialis velata. To achieve this end, we first exposed its prey, the midge Chironomus riparius, to trace elements in a contaminated lake located near a nonferrous metal smelter in northwestern Quebec. Concentrations of five of the six trace elements reached a steady state in prey within one week. When predators were exposed to these contaminated prey, their trace element concentrations increased markedly for all of the trace elements studied. In contrast, exposure of S. velata to contaminated lake water led to no significant increase in their concentrations of five of the six trace elements ([Pb] increased only slightly). Additional treatments in which the predator was exposed to these trace elements in both food and water or in a combination of food and water and sediment did not lead to further increases in its contaminant concentrations beyond those measured in the food-only treatment. We conclude that food (prey) is the almost exclusive source of As, Cd, Co, Cu, and Zn for S. velata and that it is the source of 94% of its Pb. Model curves for trace element accumulation over time by the predator fit our measured data well, and trace element concentrations in food alone are sufficient to model the exchange of these contaminants in this insect.     

溴氰菊酯在烟草上的使用安全性评价研究

目的了解昆明烟草生产投入品溴氰菊酯的安全性。方法在烟草上使用7.5 g.ai/hm~2(商品量300 m/hm~2)和12.5 g.ai/hm~2(商品量500 mL/hm~2)2.5%溴氰菊酯乳油,使用气相色谱仪检测初烤烟叶中的溴氰菊酯残留量,并应用农药残留风险的评估方法分析溴氰菊酯在烟草上使用的安全性。结果药后20 d初烤烟叶中溴氰菊酯残留量低于1 mg/kg(0.89~0.94 mg/kg),随着施药浓度的增加,溴氰菊酯残留量无显著累积性;溴氰菊酯最终残留量为1 mg/kg时,安全性达到375倍,农药长期膳食暴露量的贡献率(contribution rate,R)为0.98(R1),R值越小,说明安全性越高。结论溴氰菊酯最终残留量小于1 mg/kg时,溴氰菊酯对吸烟人群的影响在安全范围内。     

Excretion of deltamethrin in lactating dairy cows

A study was conducted to determine the metabolic fate of deltamethrin in lactating cows after a 'pour-on' application. Two cows were treated with 0.1 g deltamethrin and two with 1 g of the compound. Urine, faeces, milk and blood were collected over an 8-day period and analyzed for deltamethrin. This preliminary experiment has shown that it is necessary to undertake further experiment of longer duration (1 month). Deltamethrin was rapidly absorbed and slowly excreted. In milk, residues levels were very low: less than 1% of the treatment dose, and maximum levels were reached after 2 days (0.009 micrograms/ml for 0.1 g deltamethrin and 0.053 micrograms/ml for 1 g deltamethrin). For cows 1 and 2 (0.1 g deltamethrin), no residue level was detected at the detection limit (0.001 micrograms/ml) after 8 days. A total of 0.3-0.6% of excreted deltamethrin was present in urine, and no residue was found after 8 days. The major route for elimination was via faeces (about 95% of the total eliminated compound). Maxima were reached after 2 days and were still present after 8 days. Results shown in this study substantiate previously published work.