化学杂交剂SQ-1在谷子叶片和小穗中的残留消解动态

Residues and Decline of Chemical Hybridizing Agent SQ-1 in Leaves and Spikelets of Foxtail Millet

建立化学杂交剂SQ-1在谷子叶片和小穗中残留检测的高效液相色谱法,并研究其在谷子叶片和小穗中的消解动态。样品经乙腈提取,N-丙基乙二胺净化,外标法定量。该检测方法在1~1 000 mg/L范围内,化学杂交剂SQ-1质量浓度与色谱峰面积呈良好的线性关系,线性方程为y=30 377x+27 634,相关系数为0.999 9,最低检出限为0.05 mg/kg。在10~500 mg/kg添加范围内,化学杂交剂SQ-1在谷子叶片和小穗中的平均回收率为87.0%~95.5%,相对标准偏差为0.74%~2.28%。结果表明:化学杂交剂SQ-1可以从谷子叶片运输到小穗中,在小穗中的动态变化呈现出'先升高后降低'的趋势。其在谷子叶片中的半衰期为1.83~2.08 d,在喷施21 d后叶片中几乎检测不到化学杂交剂SQ-1残留,而在小穗中的半衰期为25.21~28.41 d,其消解速度明显慢于叶片中的消解速度。

A high performance liquid chromatography method was developed for determining chemical hybridizing agent SQ-1 and its dissipation curve in leaves and spikelets of foxtail millet. The samples were extracted with acetonitrile, cleaned up with N-propylethylenediamine(PSA) and quantified by the external standard method. There was a good linear relationship between the peak area and concentration of SQ-1 over the range from 1 to 1 000 mg/L, and the linear equation was y = 30 377 x + 27 634, with a correlation coefficient of 0.999 9. The lowest detectable concentration was 0.05 mg/kg. The mean recoveries of SQ-1 in leaves and spikelet of foxtail millet varied from 87.0% to 95.5% with a relative standard deviation ranging from 0.74% to 2.28% at fortification levels of 10–500 mg/kg. The results indicated that SQ-1 could be transported from leaves to spikelets. The trend of SQ-1 residual dynamics was first increased and then decreased. The halflives of SQ-1 were 1.83–2.08 days in leaves and no SQ-1 pesticide residues were detected after 21 days. The half-lives of SQ-1 were 25.21–28.41 days in spikelets, and its degradation rate in spikelets was significantly lower than in leaves.