毛织物中防蛀剂含量测定不确定度评定

Evaluation on uncertainties in determination of permethrin in wool fabric

根据FZ/T 20003—2007《毛纺织品防虫蛀剂含量化学分析方法》,将毛织物经甲醇浸泡,超声提取,过滤后,由高效液相色谱仪分离氯菊酯异构体并对其作定量测定。对高效液相色谱法测定毛织物中氯菊酯含量的不确定度进行了分析,评估了测定过程中影响结果的各个分量,最终合成总的不确定度。取包含因子k=2(约95%的置信概率),毛织物中氯菊酯的含量为138.31 mg/kg时,扩展不确定度u=10.24 mg/kg。结果表明标准工作液、配制标准溶液以及样品提取回收率、样品重复测定是贡献最大的不确定度分量。

According to FZ/T 20003--2007 standard, the wool fabric is soaked and ultrasonic extracted by methanol. After filtration, permethrin isomers are separated and the content are determined with high performance liquid chromatography. The sources of uncertainty are analyzed to compose steps for whole determination procedure. The various components which will influence the result during the determination are analyzed and evaluated in detail. The uncertainty of each component was evaluated and synthesized. Taking the coverage factor k = 2 （confidence probability was about 95% ） , the content of permethrin in wool fabric was 138.31 mg/kg, and the expanded uncertainty u = 10.24 mg/kg. The results showed that the reproducibility of standard solution and sample measurements, concentration of the standard solution, the recovery of permethrin during extraction are the main factors influencing the determination process of permethrin.