微波消解石墨炉原子吸收法测定水产品中铅的研究

Determination of lead in aquatic products by microwave digestion GF-AAS

采用微波消解进行样品前处理,以磷酸二氢铵作为基体改进剂,建立了分析水产品中铅含量的石墨炉原子吸收法,并对样品前处理方法和检测条件进行探讨与优化。结果表明,通过添加基体改进剂,仪器的响应值显著增加;样品铅浓度范围在0～50μg/L之间时,铅浓度与其吸光度呈良好的线性关系,相关系数为r=0.9990。利用国家标准物质牡蛎和对虾验证了方法的准确度与精密度,测定值在标准物的允许误差范围内,相对标准偏差分别为2.7%和3.3%,回收率分别为96.2%、94.8%和106.0%、96.5%。表明该方法具有简便、快捷、灵敏度高、准确可靠等优点,适合水产品中铅含量的检测。

A graphite furnace atomic absorption spectrometry （GF-AAS） was developed for determination of lead in aquatic products, which was digested by microwave and added ammonium dihydrogen phosphate （ADP） as matrix modifier, and means of samples pre-processing and detecting conditions were optimized. The results of analysis demonstrated that the standard curves of lead concentrations and absorbance were linear in the range of 0-50 ug/L lead and the correlation coefficient was r=0.9990, and the responses of atomic absorption spectrometer were remarkably increased by adding ADP as matrix modifier. The accuracy and precision of this method were tested by national standard substances （oyster and shrimp）. It showed that the relative standard deviations were 2.7% and 3.3% and the recovery was 96.2%, 94.8%, 106.0% and 96.5% in the range of permissible error of measured value. Therefore, GF-AAS has the characteristics of high sensibility and could quantify exactly with a relatively rapid and simple procedure, and is suitable for determination of lead in aquatic products.