环境水样中磺酰脲类除草剂的前处理方法研究

发布时间：2018-04-29 16:20

本文选题：磁固相萃取 + 液液萃取　；参考：《青岛理工大学》2015年硕士论文

【摘要】：磺酰脲类除草剂在治理杂草方面使用甚广。这类除草剂水溶性较强,易造成水体污染,在土壤中残留会对后茬较为敏感的农作物造成极大危害,对皮肤、眼睛、粘膜等也有一定的刺激作用。由于这类物质在环境水样中含量很低,为提高检测的灵敏度及准确度,还需在检测前进行必要的样品前处理操作。本论文选取在我国使用范围较广的一些磺酰脲类除草剂化合物为目标分析物,建立测定其在环境水体中含量的分析方法。分别采用液液萃取(LLE)、固相柱萃取(SPE)及磁固相萃取(MSPE)作为样品前处理方法,高效液相色谱(HPLC)-紫外检测为分离检测手段,进行了系统的研究。主要内容如下:(1)建立了环境水样中10种磺酰脲类除草剂的LLE-HPLC分析方法。在确定的色谱分离条件下,优化了萃取剂的种类与体积、萃取次数、萃取时间与静置时间、水样p H及盐浓度。方法线性范围在0.02~10.0mg/L之间,检出限在0.017~0.063μg/L之间,可以满足欧盟《用水法则》中规定的农药限值小于1-5μg/L的测定要求。对青岛市棘洪滩水库地表水进行精密度与准确度的考察,相对标准偏差(RSD)小于14.1%,加标回收率在73.0%~104.6%之间。该方法无需复杂设备,操作简单,便于普及。(2)建立了环境水样中10种磺酰脲类除草剂的SPE-HPLC分析方法。采用C18固相萃取柱,优化了洗脱剂的种类与体积、水样p H及盐浓度等固相萃取条件。方法线性范围在0.02~10.0mg/L之间,检出限在0.014~0.032μg/L之间。对地表水进行精密度与准确度的考察,其相对标准偏差(RSD)小于13.0%,加标回收率在75.6%~110.6%之间。该方法比液液萃取法所用洗脱溶剂少,可同时进行多个水样的操作。(3)建立了环境水样中6种磺酰脲类除草剂的MSPE-HPLC分析方法。自制磁性多壁碳纳米管,采用X-射线衍射对其表征。考察了影响磁性固相萃取效率的因素,诸如吸附剂用量、水样p H、盐浓度、萃取及解析时间、洗脱剂种类及用量等,确定了最佳萃取条件。线性范围在0.02~10.0mg/L之间,检出限在0.001μg/L~0.004μg/L之间。对地表水进行精密度与准确度的考察,其相对标准偏差(RSD)小于9.8%,加标回收率在84.9%~106.9%之间;对自来水进行精密度与准确度的考察,其相对标准偏差(RSD)小于11.3%,加标回收率在78.2%~105.4%之间。该方法无需复杂仪器,操作简单、省时,具有较高的灵敏度。可应用于环境水样中磺酰脲类除草剂的检测。
[Abstract]:Sulfonylurea herbicides are widely used in weed control. This kind of herbicide is water-soluble and easy to cause water pollution. Residues in the soil will cause great harm to the crops which are more sensitive to the next crop. It will also stimulate the skin, eyes, mucous membrane and so on. Due to the low content of these substances in environmental water samples, in order to improve the sensitivity and accuracy of detection, it is necessary to carry out the necessary sample pretreatment before detection. In this paper, some sulfonylurea herbicide compounds which are widely used in China are selected as target analytes, and a method for determination of their contents in environmental water is established. The methods of liquid-liquid extraction (LLE), solid phase column extraction (SPE) and magnetic solid phase extraction (MSPE) were used as sample pretreatment methods, and HPLCC-UV detection was used as the separation and detection method. The main contents are as follows: 1) A LLE-HPLC method for the determination of 10 sulfonylurea herbicides in environmental water samples was established. Under certain chromatographic separation conditions, the types and volume of extractant, extraction times, extraction time and static time, water sample pH and salt concentration were optimized. The linear range was between 0.02~10.0mg/L and the detection limit was 0.017 ~ 0.063 渭 g / L, which could meet the determination requirement of the pesticide limit of 1-5 渭 g / L. The precision and accuracy of surface water of Zhihongtan Reservoir in Qingdao City were investigated. The relative standard deviation (RSD) was less than 14.1and the recovery rate was between 73.0% and 104.6%. The method is simple and easy to operate without complicated equipment. It is easy to be popularized. The SPE-HPLC method for the determination of 10 sulfonylurea herbicides in environmental water samples has been established. C18 solid phase extraction column was used to optimize the conditions of solid phase extraction, such as the type and volume of eluent, water sample pH and salt concentration. The linear range was between 0.02~10.0mg/L and the detection limit was 0.014 渭 g / L. The relative standard deviation (RSDs) of surface water was less than 13.0 and the recovery rate was between 75.6% and 110.6%. This method has less elution solvent than liquid-liquid extraction method, and can be operated on several water samples at the same time. A MSPE-HPLC method for the determination of 6 sulfonylurea herbicides in environmental water samples was established. Magnetic multi-wall carbon nanotubes were prepared and characterized by X-ray diffraction. The factors affecting the efficiency of magnetic solid phase extraction (SPE), such as the amount of adsorbent, water sample pH, salt concentration, extraction and desorption time, the type and amount of eluant, etc., were investigated. The optimum extraction conditions were determined. The linear range is between 0.02~10.0mg/L and the detection limit is 0.001 渭 g/L~0.004 渭 g / L. The relative standard deviation (RSDs) of surface water was less than 9.8, and the recovery rate was between 84.9% and 106.9%. The relative standard deviation (RSDs) of surface water was less than 11.3and the recovery rate was between 78.2% and 105.4%. The method is simple, time saving and high sensitivity. It can be applied to the determination of sulfonylurea herbicides in environmental water samples.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X832

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