Element-selective detection of pesticides by gas chromatography—atomic emission detection and solid-phase microextraction
Element-selective detection of pesticides by gas chromatography—atomic emission detection and solid-phase microextraction
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气相色谱法元素选择性检测农药——原子发射检测与固相微萃取
DOI：
10.1016/s0021-9673(94)89114-1
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发表时间：
1994
影响因子：
4.1
通讯作者：
G. Wünsch
中科院分区：
文献类型：
--
作者：
R. Eisert;K. Levsen;G. Wünsch
有机污染物尤其是农药污染物的分析是环境监测的重要手段。建立了固相微萃取（SPME）分离测定环境水样中农药残留的新方法。因此，样品制备的提取和预浓缩步骤集中在单个工艺步骤中。采用固相微萃取-气相色谱-原子发射光谱法测定有机磷农药。这种耦合技术是一种非常有选择性的分析工具。利用不同的元素发射谱线可以得到元素特征谱图，提高了该方法在环境监测中的选择性，甚至可以用于环境样品中未知化合物的鉴别。涂有聚合物（聚二甲基硅氧烷）相的熔融石英纤维用于提取有机化合物，并将其转移到GC注射器中进行热解吸和分析。挥发性农药可以有效地从含水环境样品中分离出来，如有机磷农药。该方法的精密度为8-12%（R.S.D.），取决于化合物。此外，它能够在ppb和亚ppb范围内检测极限。优化了实现最佳平衡和热脱附条件的吸附和脱附时间。测定农药在加标河水样品与此技术的报告和比较SPME建立的提取技术，即固相萃取也进行。结果表明，SPME方法分析这些极性化合物的适用性。
The analysis of samples contaminated by organic compounds, especially pesticides, is an important tool of environmental monitoring. A new isolation method has been developed for the determination of pesticides in environmental water samples using solid-phase microextraction (SPME). Thus, the extraction and preconcentration steps of sample preparation are focused in a single process step. For the determination of organophosphorus pesticides using SPME extraction and preconcentration steps a GC—atomic emission detection coupling system was used. This coupling technique is a very selective analytical tool. Element-characteristics chromatograms acquired by using different element emission lines can be obtained, enhancing the selectivity of the method in environmental monitoring, and they can be used to identify even unknown compounds in environmental samples. A fused-silica fiber coated with a polymer (polydimethylsiloxane) phase is used to extract organic compounds and transfer them into a GC injector for thermal desorption and analysis. Volatile pesticides can be efficiently isolated from aqueous environmental samples, as demonstrated for organophosphorus pesticides. This method shows a precision of 8–12% (R.S.D.), depending on the compound. Furthermore, it is capable of limits of detection in the ppb and sub-ppb range. The adsorption and desorption times to carry out the optimum equilibrium and thermodesorption conditions, have been optimized. Determination of pesticides in spiked river water samples with this technique is reported and a comparison of SPME to established extraction techniques, i.e. solid-phase extraction is also carried out. The results demonstrate the suitability of the SPME approach for analysis of these polar compounds.