论文部分内容阅读
建立了柱切换离子色谱紫外法测定西红柿中嗪草酮和乙嗪草酮的方法。西红柿样品经过乙腈超声提取、减压浓缩、再溶解得提取液。将提取液适当稀释后,直接进样至柱切换系统。采用一根AG11-HC阴离子交换保护柱对提取液进行在线前处理,将待测的除草剂通过CG12A阳离子交换保护柱进行在线浓缩,然后用CG12A和CS12A阳离子交换柱进行分离,紫外检测。样品提取液中的主要有机基质经过柱切换被冲洗入废液,避免了其对离子色谱柱造成损害。建立的方法对实际样品进行测定,结果表明,样品加标量在3.2~8.0 mg/kg时加标回收率为75.0%~85.8%。在0.25~10 mg/L范围内,方法拥有良好的线性(r2≥0.999 6)、检出限(LOD≤1.84 mg/kg)和重现性(RSD≤0.46%,n=6)。该方法有望在复杂基质样品中痕量易电离化合物的测定中得到广泛的应用。
A method for determination of metribuzin and ethafloxacin in tomato by column-switched ion chromatography was established. Tomato samples were extracted by acetonitrile ultrasound, concentrated under reduced pressure and redissolved extract. After the extract is properly diluted, it is injected directly into the column switching system. An AG11-HC anion exchange column was used to pre-treat the extract. The herbicides to be tested were concentrated online through CG12A cation exchange column and then separated by CG12A and CS12A cation exchange columns for UV detection. The main organic matrix in the sample extract is flushed into the waste fluid through the column switch, preventing it from damaging the ion column. The established method for the determination of the actual samples showed that the spiked recoveries of spiked samples ranged from 75.0% to 85.8% at 3.2-8.0 mg / kg. The method has good linearity (r2≥0.9996), detection limit (LOD≤1.84 mg / kg) and reproducibility (RSD≤0.46%, n = 6) in the range of 0.25-10 mg / L. The method is expected to be widely used in the determination of trace ionizable compounds in complex matrix samples.