石墨炉原子吸收法测定武汉市售大米中镉含量的研究

Determination of Cadmium Content in Rice from Wuhan Market Using Graphite Furnace Atomic Absorption Spectrometry

中文关键词:  石墨炉原子吸收光谱法,大米,镉,消化

英文关键词:Graphite  furnace atomic  absorption spectrometry, rice, cadmium, digest

中文摘要:

      目的 研究石墨炉原子吸收光谱法测定大米中镉含量,优化大米质量、消化试剂添加量和消化时间,确定较佳的大米样品预处理条件,并对武汉市售大米中镉含量进行测定分析。方法 采用湿法消解对样品进行前处理,测定大米镉含量的检出限、重复性、回收率和精密度。结果 较佳消化条件为大米质量1g、消化剂包括10 mL硝酸和2mL过氧化氢、时间12h。在该试验条件下,石墨炉原子吸收光谱法测定大米中镉含量的检出限为0.051μg/kg,加标回收率为98.85%。大米中镉含量随产区和品种的不同差异显著,湖南、湖北、江西等中南地区的大米镉含量较高,吉林、黑龙江等东北地区的大米镉含量较低；粳米镉含量高于糯米,籼米镉含量高于粳米。结论 该方法测定大米中的镉含量准确、试验误差小,重复性好,可以用于大米中镉含量的测定。

英文摘要:

      Objective To investigate the method of Graphite Furnace Atomic Absorption Spectrometry (GFAAS) to determine the cadmium content in rice by using the preferred sample pretreatment conditions including the amount of rice, digestion reagent, and digestion time, and also the cadmium contents in rice from Wuhan market were determined by GFAAS method under preferred sample pretreatment conditions. Methods Rice was digested by using wet digestion for sample pretreatment and the detection limits, precision, repeatability, and recovery rate of GFAAS method were determined at preferred conditions. Results The detection limit of GFAAS method to determine the cadmium content in rice was 0.051μg/kg and the recovery rate was 98.85% at the preferred sample pretreatment conditions including 1g of rice, digestion reagent of 10 mL nitric acid and 2 mL hydrogen peroxide, and 12h of digestion time. The cadmium content of indica rice was higher than that of japonica rice and glutinous rice, and the cadmium content of glutinous rice was higher than that of japonica rice. The cadmium content of rice produced in Hunan, Hubei, and Jiangxi province was higher than in Jilin and Heilongjiang province. Conclusion GFAAS method to determine the cadmium content in rice is accurate and had small test error and good repeatability at the preferred sample pretreatment conditions, and it can be utilized to determine the cadmium content in rice.