【作者】 祝海珍；

【导师】 杨明敏；

【作者基本信息】 南京农业大学 ， 食品科学， 2008， 博士

【摘要】 近年来,食品、饮用水、环境中有害物质残留的问题越来越引起人们的重视,为了保护人们的身体健康,WHO/FAO-CAC对食品中各种有害物质残留作了相应的最高残留限量（MRL）的规定。开发一种符合规定的简单、快速、有效的样品前处理技术以及具有高灵敏度和高选择性的残留检测技术就显得十分重要。本论文共分二个部分:第一部分:用三种不同的检测方法检测蔬菜样品中的农药残留敌百虫。1.敌百虫催化过硼酸钠氧化联苯胺生成4-氨基-4′-硝基联苯,这一催化产物已经得到液相色谱-质谱（LC-MS）方法的验证。采用反相高效液相色谱法（HPLC）,在365 nm处,分离检测催化产物4-氨基-4′-硝基联苯。本实验研究发现,4-氨基-4′-硝基联苯的峰面积与敌百虫浓度（0.02-0.5 mg/L）之间有一线性关系,线性系数为0.9988,最低检测限为2.0μg/L。在敌百虫催化反应的基础上,应用HPLC建立了间接检测敌百虫的方法。三个平行样品的（0.5,1.0,1.5 mg/kg）添加回收率范围为67.5-82.1%,相对标准偏差（RSD）为4.5-7.3%。采用0.01 mol/L十二烷基硫酸钠（SDS）溶液作为萃取剂,结合固相萃取（SPE）富集样品中的敌百虫。使用SDS-SPE体系获得的样品回收率与传统液液萃取方法获得的结果基本相符。这种新前处理技术大大减少了有毒溶剂的使用,满足了“绿色分析化学”的要求。2.在前一方法基础上改进了前处理方法,采用浊点萃取方法（CPE）处理样品,应用高效液相色谱-紫外检测方法直接检测产物4-氨基-4′-硝基联苯。在最优化的实验条件下,敌百虫浓度0.01-0.2 mg/L和4-氨基-4′-硝基联苯峰面积之间有一线性关系,线性相关系数为0.9965,最低检测限为2.0μg/L。自来水和大白菜的添加回收率分别为95.4-103%和85.2-91.2%,与前一种方法相比回收率提高了10-20%。其它优点是:CPE方法简便,花费低,基本不使用有毒溶剂,对环境友好,它与一些用有机溶剂的萃取方法相比较,具有广阔的应用前景。3.根据敌百虫对过硼酸钠氧化联苯胺这一缓慢反应具有很强的催化作用,发现联苯胺反应后浓度的减少与敌百虫加入浓度有线性关系。在4.38 cm长的玻璃芯片微控管道中分离联苯胺,并由碳电极进行安培检测。在最优化的实验条件下,敌百虫加入浓度0.01mmol/L～0.5mmol/L和联苯胺峰面积减少之间有一线性关系,线性相关系数为0.9934,最低检测限为5μmol/L。文中讨论了缓冲液的浓度和pH值,进样时间、分离电压,检测电位等参数对分离效率和检测信号的影响。第二部分:重金属离子的玻璃芯片毛细管电泳检测。本章报道在4.38 cm长的玻璃芯片微控管道中分离检测Cd²⁺、Zn²⁺、Cr³⁺和Hg²⁺四种重金属离子,并由碳电极进行安培检测。本法可在200 s内分离上述物质,连续15次进样检测,迁移时间的相对标准偏差（RSD）为1.121%。Cd²⁺、Zn²⁺、Cr³⁺和Hg²⁺四种重金属离子的最低检测限分别为2.5,5.8,3.5,和1.5μmol/L（信噪比S/N=3）。文中讨论了缓冲液的浓度和pH值,进样时间、分离电压,检测电位等参数对分离效率和检测信号的影响。并应用本方法检测土壤中Cd²⁺,结果良好。更多还原

【Abstract】 Residue of pesticides found in food,drinking water and environmental bad substance has raised much concern from the general public in recent years.In order to protect persons’ healthy,the maximum levels（MRL） of bad substance in food were constituted by WHO/FAO-CAC.It is important to exploit simply,fast,efficient pre-treatment technologies for samples and high sensitive,high selective detections technologies accord with regulation.The thesis includes two parts:In chapterⅠ:Three different detection methods were used to analyse residues of trichlorfon in vegetable sample.1.Trichlorfon has the capacity to catalyze the oxidation of benzidine（4, 4’-diamino-biphenyl） to 4-amino-4’-nitro biphenyl in the presence of sodium perborate.The product of the catalyzed reaction was validated by LC-MS method.Reversed-phase high performance liquid chromatography with 365 nm UV detection was used for separation and quantification of 4-amino-4’-nitro biphenyl.It can be proven there is a linear relationship between the peak areas of 4-amino-4’-nitro biphenyl and trichlorfon in the concentration range of 0.02-0.5 mg/L（r=0.9988）.Limit of detection was 2.0μg/L.A method for the indirect determination of trichlorfon using HPLC was developed based on catalytic effect of trichlorfon.Method validation was performed on samples spiked at three levels（0.5,1.0, 1.5 mg/kg）,the recoveries ranged from 67.5 to 82.1%,with relative standard deviations between 4.5 and 7.3%.0.01 mol/L sodium dodecyl sulphate（SDS） solution Was used to extract trichlorfon from samples and solid-phase extraction was used to isolate and concentrate trichlorfon in SDS solution.The recoveries of trichlorfon obtained with percolating the extraction through a SPE system were essentially in agreement with those obtained by liquid-liquid extraction.This new isolation technique decreases the use of toxic solvents and satisfies the requirements of Green Analytical Chemistry.2.On basis of the former method,we have improved on pre-treatment technologies.The sample is extracted with a cloud point extraction method and then detected using a high performance liquid chromatography with ultraviolet detection（HPLC-UV）.Under the optimum experimental conditions,there was a linear relationship between trichlorfon in the concentration range of 0.01-0.2 mg/L and the peak areas of 4-amino-4’-nitrobiphenyl（r= 0.996）.Limit of detection was 2.0μg/L,recoveries of spiked water and cabbage samples ranged between 95.4-103%and 85.2-91.2%,respectively.Compared with the former method,recoveries were improved 10-20%.It was proved that the cloud point extraction （CPE） method was simple,cheap,and environment friendly than extraction with organic solvents and had more effective extraction yield.3.According to the fact that trichlorfon had strong catalytic effect on the decolour reaction between sodium perborate oxidation benzidine,we found that there was a linear relationship between the joining concentration of trichlorfon and the decreasing concentration of benzidine after reaction.Separation and direct detection of benzidine in 4.38 cm separation channel made of glass with end-column amperometric detection at a carbon electrode was developed.Under the optimum experimental conditions,there was a linear relationship between trichlorfon in the concentration range of 0.01-0.5 mmol/Land the peak areas of benzidine（r=0.9934）.Limit of detection was 5μmol/L.Variances influencing the separation efficiency and amperometric response,including concentration and pH of buffer solution,injection time,separation voltage or detection potential are assessed and optimized.In chapterⅡ:Heavy metals were detected with glass capillary electrophoresis.Separation and direct detection of Cd²⁺、Zn²⁺、Cr³⁺and Hg²⁺in 4.38 cm separation channel made of glass with end-column amperometric detection at a carbon electrode was developed.The migration time is less 200 s and the reproducibility of migration of Zn²⁺ is satisfactory with relatime standard deviation（RSD） of 1.121%in 15 successive injections. The limits of detection of Cd²⁺、Zn²⁺、Cr³⁺and Hg²⁺ are estimated to be 2.5,5.8,3.5 and 1.5μmolL^-1 at S/N=3,respectively.Variances influencing the separation efficiency and amperometric response,including concentration and pH of buffer solution,injection time, separation voltage or detection potential are assessed and optimized.The method has been applied to the determination of Cd²⁺ in soil with satisfactory result.更多还原