固相萃取-高效液相色谱法考察可溶性有机物对绿麦隆在小麦体内积累的影响

目的]建立了固相萃取-高效液相色谱法研究可溶性有机物对绿麦隆在小麦体内积累的影响。方法]采用乙腈-水为提取溶剂,通过固相萃取Sep-pak C₁₈柱分离和混合模式的GCC-SAX-PSA串联柱净化,反相高效液相色谱法定量分析了2种可溶性有机物(DOM)对绿麦隆在小麦体内积累的影响。结果]该方法最小检出限为2×10-10g,最低检出质量分数为0.05 mg/kg,小麦叶片和根系中绿麦隆添加回收率为85.7%、92.4%,变异系数0.2%、2.8%。结论]研究发现绿麦隆施药质量分数较低(5 mg/kg)时,可溶性有机物可以降低绿麦隆在小麦幼苗体内的含量,可降低其生物毒性;当施药质量分数较高(10、25 mg/kg)时,可溶性有机物使绿麦隆在小麦幼苗体内的含量增高,增大其生物毒性。来源于稻草的可溶性有机物对小麦幼苗吸收绿麦隆的影响强于来源于污泥的可溶性有机物,并且随可溶性有机物浓度的增高,影响增大。

Study on Effect of Dissolved Organic Matter on Chlorotoluron Accumulation in Wheat Seedling by Solid-phase Extraction and Reversed Phase High Performance Liquid Chromatography

Aims] An improved reversed phase high performance liquid chromatographic method for the determination of chlorotoluron in leave and root of wheat was established. Methods] The method involved an initial extraction of the wheat with acetonitrile-water. Implementation of a mixed-mode solid-phase extraction Sep-pak C18 and GCC-SAX-PSA SPE cartridges was discussed as a promising approach for wheat clean-up. The effect of dissolved organic matter on chlorotoluron accumulation in wheat seedling was studied. Results] The chlorotoluron content was determined by high performance liquid chromatography with UV detection. Recoveries of chlorotoluron was 85.7-92.4% and with coefficient of variability of 0.2-2.8%. The minimum detectable amount of chlorotoluron was 2 ×10-10 g, and minimum detectable concentration was 0.05 mg/kg. Conclusions] The results showed that treatment dissolved organic matter induced decrease in chlorotoluron content of wheat seedling with the initial concentration(5 mg/kg) of chlorotoluron in soil and increase in chlorotoluron content of wheat seedling with the initial concentration(10-25 mg/kg) of chlorotoluron in soil. The effect of soluble organic matter from straw on the absorption of chlorotoluron in wheat seedlings was stronger than that from sludge, and the effect increased with the increase of the concentration of soluble organic matter.