定容因子与称样质量对稻米中镉含量测定的影响研究  

Study on the effects of constant volume factor and sample mass on the determination of cadmium content in rice

作　　者：张大诚 李发启 彭灿 胡丽 谭小文 ZHANG Da-cheng;LI Fa-qi;PENG Can;HU Li;TAN Xiao-wen(Changde Grain,Oil and Food Quality Inspection and Testing Center,Changde 415000,China)

机构地区：[1]常德市粮油食品质量检测中心,湖南常德415000

出　　处：《粮食与饲料工业》2025年第1期108-111,共4页Cereal & Feed Industry

摘　　要：采用原子吸收法测定稻米中镉含量,研究了定容因子、称样质量对测定稻米中镉含量的影响。通过比较低浓度、中等浓度、高浓度的样品在不同的定容因子下的表现,得出样品浓度越大,定容因子对结果影响越大,测定值相对误差越大。通过调整定容因子和称样质量,使样品待测液中镉的浓度处在1.0~2.0 ng/mL时,测定结果更加接近真实值。对0.18、0.32和0.87 mg/kg的样品,称样质量为0.3 g,定容因子分别为25、50、100 mL的实验准确性与精密度进行了研究,6次测定平均值与样品标准值相对误差低于5.1%,相对标准偏差(RSD)低于3.5%。研究表明称样质量为0.2~0.5 g时,选用适当的定容因子实验测定结果会更加准确可靠,这为稻米中镉含量的日常测定和实验室质量控制提供了参考和依据。The cadmium content in rice was determined using atomic absorption spectrometry,and the effects of constant volume factor and sample mass on the determination results were investigated.By comparing samples of low,medium,and high concentrations with different constant volume factors,it was found that as sample concentration increased,the impact of the constant volume factor on the results became more significant,leading to greater relative error in the measured values.By adjusting the constant volume factor and sample mass to ensure that the cadmium concentration in the test solution remained within 1.0-2.0 ng/mL,the measurement results were closer to the true values.The accuracy and precision of experiments were examined for samples of 0.18 mg/kg,0.32 mg/kg,and 0.87 mg/kg,using a sample mass of 0.3 g and constant volume factors of 25 mL,50 mL,and 100 mL,respectively.The relative error between the mean of 6 measurements and the standard sample value was below 5.1%,and the relative standard deviation(RSD)was below 3.5%.The study indicates that when the sample mass is 0.2-0.5 g,selecting an appropriate constant volume factor leads to more accurate and reliable results,providing a reference for the routine determination of cadmium content in rice and laboratory quality control.

关 键 词：镉 定容因子 质量控制 原子吸收法 

分 类 号：TS210.7[轻工技术与工程—粮食、油脂及植物蛋白工程]