快速溶剂萃取-双ECD气相色谱法测定土壤中的23种有机氯
2021-07-16魏小华石浚哲
魏小华 石浚哲



摘要 [目的]修正《土壤和沉积物 有机氯农药的测定 气相色谱法》(HJ 921—2017)中关于测定23种有机氯的错误。[方法]采用ASE快速溶剂萃取对土壤样品进行前处理,通过双柱气相色谱(ECD)法对土壤中23种有机氯农药进行监测,并用外标法定量,建立土壤中23种有机氯农药的双柱气相色谱(ECD)分析方法。[结果]该方法土壤取样量为5.0 g,23种有机氯农药标准曲线有良好的线性,决定系数(R2)在0.998以上,两柱检出限分别为0.11~0.66 μg/kg(DB-5柱)和0.09~0.53 μg/kg(DB-1701柱),相对标准偏差分别为0.87%~4.92%(DB-5柱)和0.52%~4.94%(DB-1701柱),实际样品加标回收率除狄氏剂和o,p′-DDD回收率偏低外,其他目标物为70%~120%。[结论]该方法简单高效,适合土壤中23种有机氯农药的残留分析测定。
关键词 土壤;双柱双ECD;有机氯农药
中图分类号 X-833 文献标识码 A 文章编号 0517-6611(2021)12-0204-05
doi:10.3969/j.issn.0517-6611.2021.12.054
开放科学(资源服务)标识码(OSID):
A Study of 23 OCPs in Soil by Accelerated Solvent Extraction with Dual Chromatographic Columns and Dual ECD
WEI Xiao hua, SHI Jun zhe
(Wuxi Environmental Monitoring Central, Jiangsu Province, Wuxi, Jiangsu 214000)
Abstract [Objective] To correct the mistakes about determining 23 OCPs in Soil and Sediment—Determination of OCPs—Gas Chromatography(HJ 921—2017). [Method] A double column gas chromatography (ECD) method was established for the determination of 23 OCPs in soil by accelerated solvent extraction and external standard method [Result] The soil sample quantity is 5.0 g and there were good linear relationship of 23 OCPs, the coefficient of determination (R2) was greater than 0.998. The experimental results showed that the detection limits were in the range of 0.11-0.66 μg/kg (DB 5 Columns) and 0.09-0.53 μg/kg (DB 1701 Columns), and the relative standard deviations were 0.87%-4.92% (DB 5 Columns) and 0.52%-4.94%(DB 1701 Columns). The recovery rate of the sample was 70%-120% except dieldrin and o,p′ DDD. [Conclusion] The method is simple, efficient and high sensitivity, and suitable for the determination and analysis of residues of 23 OCPs in soil.
Key words Soil;Dual chromatographic columns and dual ECD;OCPs
有機氯农药类化合物属于持久性污染物,性质稳定,不易分解,具有生物累积性,对生态环境和人体健康有潜在威胁[1-2]。因此,加强对环境中有机氯农药类化合物的监测十分重要。
快速溶剂萃取通过高温、高压对目标化合物实现快速、高效的提取,可节省溶剂[3-6]。ASE操作简便,重现性好,双柱气相色谱(ECD)分析方法既能定性亦能通过前后柱的对比分析有效去除假阳性的干扰,分离效果好、准确度高[7-8]。因此,笔者采用ASE快速溶剂萃取对土壤中23种有机氯农药类化合物进行处理。
1 材料与方法
1.1 试验材料
1.1.1
仪器。Agilent 7890 A 双ECD 气相色谱仪(Agilent 7693 Auto sampler 自动进样平台);DB-1701毛细管色谱柱(30.0 m×0.53 mm×1.0 μm);DB-5毛细管色谱柱(30.0 m×0.53 mm×0.88 μm);Dionex ASE350 快速溶剂萃取仪(Thermo Scientific),配34 mL萃取池;DC12H型氮吹浓缩仪。……
