石墨炉原子吸收光谱法和胶体金快速定量法测定粮食中铅的对比研究

Comparative Study on Determination of Lead in Grain by Graphite Furnace Atomic Absorption Spectrometry Method and Rapid Quantitative Method of Colloidal Gold Technique

通过对石墨炉原子吸收光谱法和胶体金快速定量法测定粮食中铅的检出限、定量限、准确性、重复性、检测时长和适用性等参数进行测试,为粮食中铅的检测方法的选择提供了实验依据。结果表明,不同粮食作物检出限不同,小麦的检出限最低,玉米次之,大米最高,两种方法的检出限和定量限均满足粮食中铅测定的质量控制要求且石墨炉原子吸收光谱法的检出限更低;对大米/糙米、小麦和玉米不同浓度的阳性样品进行检测,两种方法的测定结果无显著性差异;对大米/糙米、小麦和玉米中铅的重复性试验,两种方法的精密度均满足国标检测要求;单个样品的检测时长,从称量到读取数据石墨炉原子吸收光谱法需要12 h,而胶体金快速定量法仅需35 min即可完成。

The limit of detection, limit of quantitation, accuracy, repeatability, detection time and applicability of lead in grain were determined by graphite furnace atomic absorption spectrometry and rapid quantitative method of colloidal gold technique, which provided a reliable basis for selection of detection methods of lead in grain. The results showed that the limit of detection of different grains was different, in which wheat was the lowest, maize was the second, and rice/brown rice was the highest. The limit of detection and the limit of quantitation of the two methods met the quality control requirements of the determination of lead in grain, and the limit of graphite furnace atomic absorption spectrometry was lower. There was no significant difference in the detection results of positive samples of rice/brown rice, wheat and maize with different concentrations. The precision of the two methods can meet the requirements of Chinese standard for the repeatability test of lead in rice/brown rice, wheat and maize. For a single sample from weighing to reading the data, it takes 12 hours by graphite furnace atomic absorption spectrometry, while rapid quantitative method of colloidal gold technique can be completed within 35 minutes.