曲拉通和硝酸混合溶液直接提取快速测定草鱼中铅含量

Introduction to the Direct Extraction and Rapid Determination ofLead in Grass Carps with Mixture of Triton and Nitric Acid

为建立快速测定草鱼中铅含量的方法,通过分析曲拉通和硝酸混合溶液浓度、提取时间、称样定容体积比例等因素的影响,以及基体改进剂的使用效果,确定了草鱼中铅元素提取测定的最佳条件。验证结果显示:采用曲拉通和硝酸混合溶液提取草鱼中铅元素方法的提取率为86.5%~95.6%,加标回收率为91.5%~95.6%,精密度均小于4.0%,检出限和定量限分别为0.011和0.032 mg/kg,满足了国家标准GB 5009.12—2017第一法石墨炉原子吸收光谱法的要求。与国家标准方法比较,本研究建立方法的样品前处理时间从4~12 h缩短至0.2 h内,酸试剂用量从湿法消解的7~12 mL减少至1~2 mL;前处理过程无需高温消解,无需其他前处理设备,避免了样品污染和待测元素损失,实现了降低分析成本以及保护环境和试验人员的目的。结果表明,该方法是一种简单、准确、绿色、快速测定草鱼中铅含量的方法,尤其适合大量样品检测。

In order to establish a rapid method to determine lead content in grass carps,the best conditions for the extraction and determination of lead in grass carps were determined through analyzing the concentration of the mixture of triton and nitric acid,the extraction time,the volume ratio of the weighed sample to constant volume,and other factors as well as the effect of matrix modifier.It was verified that the extraction rate by the mixture ranged from 86.5%to 95.6%,the standard recovery rate was from 91.5%to 95.6%,the degrees of precision were all less than 4.0%,and the detection limit and quantitation limit were 0.011 and 0.032 mg/kg,respectively,which conformed to the requirements of the national standard GB 5009.12—2017,the first method of graphite furnace atomic absorption spectrometry.Compared with the national standard,the sample pretreatment time of the established method was shortened from 4-12 hours to 0.2 hours,and the amount of acid reagent was reduced from 7-12 mL of wet digestion to 1-2 mL;no high temperature digestion or other pre-treatment equipment were required during the pre-treatment process,which avoided any sample pollution and loss of elements to be measured,and achieving the purpose of reducing analysis cost and protecting the environment and testing personnel.In conclusion,the established method was simple,accurate and environment protecting for rapid determination of lead content in grass carps,especially for a large amount of samples.