微波消解-石墨炉原子吸收光谱法检测紫菜中的镍

Determination of Nickel in Porphyra Samples by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry

本文选择日常中最为常见的食用藻类-紫菜作为样品对象,根据紫菜样品检测的实际需要,应用近年来已日渐成熟的样品消解技术-微波消解代替湿法消解或高压消解等传统模式消解样品,并对石墨炉原子吸收光谱法进行细节性优化的基础上,测定紫菜样品中的镍含量。实验结果表明,经本方法测得的标准曲线相关系数r一般可保持在0.999以上。对市场采购的不同批次紫菜样品进行样品本底检测和同一浓度的加标回收率实验,回收率保持在87%~101%。同时应用国家标准物质-紫菜成份分析标准物质进行质量控制,6次平行测定结果全部落在标准物质证书的标准值及不确定度范围内,相对标准偏差RSD为3.01%。证明该方法能够有效地达到质量控制目的,溯源性好,检测结果准确率高,完全可以满足紫菜样品中镍含量的精密检测,并且可以作为参考运用于其它类似食品的镍含量检测工作中。

According to actual demands for determination of porphyra samples,the commonly edible marine algae,it applied microwave digestion,the progressively mature technology of samples digestion,replacing traditional methods such as wet digestion or high pressure digestion,moreover,it made targeted optimization for graphite furnace atomic absorption spectrometry,for the purpose of determining nickel content in porphyra samples. The results of analysis demonstrated that the correlative coefficient r of standard curve was generally kept above 0. 999 by captioned method. Determining background contents and corresponding recovery rates with the same concentration level of Porphyra samples from different batches,all the recovery rates could reach 87% ~ 101%. It also showed that the six parallel results of national standard substance（ Porphyra） kept within the permissible range of certification,the relative standard deviation was 3. 01%. To conclude,with effectively quality control,visible traceability and high accuracy of determination results,microwave digestion- graphite furnace atomic absorption spectrometry was suitable for determining nickel content in Porphyra samples,which also provided operational reference program for determining nickel content in similar samples.