原子吸收分光光度法测定甲基纤维素中的重金属含量

Determination of heavy metal elements in methylcellulose by atomic absorption spectrometry

目的:建立原子吸收分光光度法测定甲基纤维素中4种重金属元素(铅、镉、砷、汞)的含量。方法:样品经微波消解后,采用石墨炉法测定铅和镉的含量,采用原子荧光法测定砷和汞的含量,并对测定方法进行了方法学考查。结果:3个厂家10批样品的重金属含量均符合要求。4种元素在各自的浓度范围内具有良好的线性关系(相关系数 r 均大于0.999),精密度试验RSD为1.5%~2.9%,平均回收率为84.1%~104.1%。结论:该方法结果准确,灵敏度高,具有良好的重现性,适用于测定甲基纤维素中铅、镉、砷、汞的含量。

Objective: To establish an atomic absorption spectrometry (AAS) method for the determination of four heavy metal elements (Pb, Cd, As, Hg) in methylcellulose. Methods: After microwave digestion, the contents of Pb and Cd were determined by graphite furnace atomic absorption spectrometry (GF-AAS) method, while the contents of As and Hg were determined by atomic fluorescence spectrometry. We also verified the methodologies. Results: The contents of heavy metal elements in ten batches of methylcellulose samples from three factories complied with the requirements. The four heavy metal elements showed good linearity in their respective concentration ranges (correlation coefficient r values were all greater than 0.999).The precision RSD values ranged 1.5%~2.9%, and the average recoveries ranged 84.1%~104.1%. Conclusion: The established method is accurate, sensitive and reproducible. It is suitable for the determination of heavy metal elements (Pb, Cd, As, Hg) in methylcellulose.