两种苯并咪唑类杀菌剂高效液相色谱分析方法及其环境行为研究

【作者】 郭英娜；

【导师】 李金昶；

【作者基本信息】 东北师范大学 ， 分析化学， 2004， 硕士

【摘要】 已有调查表明，人类癌症的发病率与农药的使用量呈平行关系。因此，农药的大量使用，已对全世界的环境和人类身体健康造成了重大的危害。近年来杀菌剂的产量逐年上升。苯并咪唑类杀菌剂由于它们的广谱、低毒而得到广泛使用。但它们仍然有一定的毒性，在环境中比较稳定，而且由于它们的内吸性还可以在植物体内残留。因此，对它们在水、土壤中的残留状况进行分析研究有实际意义。固相萃取技术（SPE）是近些年来发展起来的样品处理方法。它具有操作简单、省时、安全、溶剂用量少、不易乳化以及高富集因子等优点，广泛应用于痕量有机物的分离富集。本论文简要介绍了固相萃取的基本原理、富集装置及影响萃取效率的因素和在环境分析中的应用及发展趋势，介绍了固相萃取新技术。获得的主要研究结果如下：1.对高效液相色谱测定条件进行了优化。通过试验确定：分析柱为ODS柱，检测波长为286nm，流动相为甲醇/水=50:50(v/v)，流速为0.7mL/min，柱温为55oC。2.选定3M Empore 6mL C18相作为富集水样中苯并咪唑类杀菌剂的固定相。研究了影响方法回收率的诸多因素，优化了固相萃取条件。选定甲醇为洗脱剂；洗脱剂的用量为2mL；向水样中加入1%甲醇作为改性剂可加大苯并咪唑类杀菌剂的回收效果；样品以10mL/min的流速通过萃取柱较为合适；水样的pH值基本上对苯并咪唑类杀菌剂的回收率没有影响；水样中氯化钾的质量浓度为5g/L。并对此作了理论上的探讨。3.通过研究苯并咪唑类杀菌剂在水体中的降解状况得知，水解速率与温度和pH值有关。在太阳光照下，在纯水中光解速率较快，丙酮<WP=5>加速光解；而在紫外灯下光解速率很快，只有几十个小时。4.研究了多菌灵和噻菌灵在长春地区四种典型土壤中的吸附状况。结果表明，影响吸附的主要因素是有机碳含量。从有机碳吸附常数看，多菌灵和噻菌灵均具有“中等移动性”，说明它们在土壤中的迁移性较差。5.检测了多菌灵和噻菌灵在实际水样中的残留状况。固相萃取有效地消除了杂质的干扰。测定结果的精密度和准确度都很好。更多还原

【Abstract】 Some research has testified that the incidence of cancer disease has direct ratio to the use of pesticides. With the use of a lot of pesticides, there was harm to human being’s health and the environment in the world. In recent years, the fungicide’s yield increases year after year. Benzimidazolic compounds were used widely because of their broad-spectrum, high- performance and little toxicity. But they still have some toxicity, were steady in the environment, and they could stay in the vegetable because they were systemic fungicide. Therefore, the analysis into their persistence in the water and the soil was of great importance.Solid phase extraction (SPE), as a sample pretreatment technique was developed in the recent years. It had the advantage of analytical speed, simplicity, low costs, safety, no emulsification, flexibility and high preconcentration factor, and was used to separate and preconcentrate lots of organic analytes. This article totally described the development, principle, performing procedure, devices and the factors influencing process and recovery of SPE. Its applications in environmental analysis were also well reviewed. Furthermore, the detection methods and its trend were summarized. Finally the new techniques of solid phase extraction were outlined.The main conclusions were as follows: 1. The best chromatographic conditions were UV detection wavelength of 286nm, mobile phase of methanol/water at 50/50(v/v), mobile phase flow rate of 0.7mL/min, column temperature of 55 oC, the column used was ODS, were used to determine the benzimidazolic compounds in the environment.2. 3M Empore 6mL C18 was selected as the best solid phase for extracting trace benzimidazolic compounds in water samples. In addition, most of the influencing factors were studied and optimized. The result <WP=7>showed that methanol was the preferred elution solvents for the absorbed benzimidazolic compounds. When the elution solvent (2mL) was selected, the variation of recoveries as a function of the volume of elution solvent used can be determined. The addition of 1% methanol into the sample prior to spiking could greatly improve the recoveries. The flow rate of sample loading was 10mL/min. The acid of samples had no influence on the recoveries. Meanwhile, the concentration of potassium chloride in the water was 5 g/L. What’s more; these were discussed in the theory. 3. The degradation of the benzimidazolic compounds was investigated in the water. The results showed that hydrolysis of the benzimidazolic compounds depended on both pH and the temperature. The rate of photo degradation in the water under sunlight was very slow, when acetone was added, the rate was fast. However, the rate of photo degradation was much faster than those, when it was under UV lamp, only several ten hours. 4. Research on the adsorption of carbendazim and thiabendazole in four different types of soil in Changchun region showed that the content of organic carbon was the major factor of adsorption in the soil. From the organic carbon adsorption constant, carbendazim and thiabendazole had middling transference, suggesting that they had worse transference in the soil. 5. In the analysis of real samples such as surface run-off water, Solid phase extraction technique enabled the elimination of matrix interference and the work was possible.更多还原