大米中重金属镉的检测方法研究

Study on the detection method of heavy metal cadmium in rice

精减了传统的微波消解法测定大米中重金属镉的试验步骤.用酸以更快速高效的方式对大米中的有机物进行消解,在酸性条件下用原子吸收分光光度计进行测量,以标准曲线法定量,减少了试验中转移消化液的步骤.结果表明:镉质量浓度在0~5 ng/mL范围内线性良好,线性回归方程Y=0.10822X、相关系数r^(2)=0.9997、加标回收率97.8%~103.30%、相对标准偏差(relative standard deviation,RSD)1.30%~3.36%、方法检出限和定量限分别为0.001和0.003 mg/kg.方法相对于GB 5009.15-2014爯食品安全国家标准食品中镉的测定爲处理更简化,且未降低灵敏度,重复性好,准确可靠,可作为检测机构日常大米中镉的检测方法推广.

The traditional experimental steps of microwave digestion for the determination of cadmium in rice were simplified.Using acid to digest the organic matter in rice in a faster and more efficient way,measure it with an atomic absorption spectrophotometer under acidic conditions,and quantify it with a standard curve method,which reduced the steps of transferring the digestive juice in the experiment.The results showed that the linear range of cadmium concentration was 0~5 ng/mL,the linear regression equation was Y=0.10822 X,the correlation coefficient was r^(2)=0.9997,the recovery rate was 97.8%~103.30%,the relative standard deviation(RSD)was 1.30%~3.36%.The limits of detection and quantification were 0.001 and 0.003 mg/kg,respectively.Compared with GB 5009.15-2014"national food safety standard determination of cadmium in food",this method was simple,sensitive,reproducible,accurate and reliable,and can be used as a routine detection method for cadmium in rice.