卫生研究

目的 研制冻干人尿中铬标准物质。方法 采集正常人尿经混合、过滤后作为基质，通过加标、混匀、分装、冷冻干燥制备而成；使用电感耦合等离子体质谱仪对其均匀性、稳定性进行检验后，由7家实验室采用2种方法进行合作定值，并对尿铬研制物的不确定度进行评定。结果 研制的标准物质最小取样量为0.50 mL,2个水平的均匀性检验值F分别为1.79和1.77,差异无统计学意义。冻干标准物质在≤4℃下保存可稳定12个月，复溶后的标准物质溶液在4℃下可稳定7 d。2个水平的标准量值及不确定度分别为(16.0±1.0)和(30.7±2.1)μg/L(k=2)。结论 研制的标准物质各项指标符合国家相关要求，可用于实验室人尿中铬检测的质量控制。

OBJECTIVE To develop the certified reference material in freeze-dried human urine.METHODS Normal human urine was collected, mixed and filtered as a matrix, then the urine was prepared by adding standard, mixing, sub-packaging, and freeze-drying; After the homogeneity and stability were tested by inductively coupled plasma mass spectrometer, the urine were determined by two methods in seven independent laboratories and the uncertainty of the certified reference material was evaluated.RESULTS The minimum sample intake of the developed certified reference material was 0.50 mL, and the homogeneity was good. The freeze-dried material was stable for 12 months at ≤4 ℃, and the reference material was stable at 4 ℃ after reconstitution for the 7 d.The standard value and uncertainty of the two levels were(16.0±1.0) μg/L and(30.7±2.1) μg/L(k=2),respectively.CONCLUSION The certified reference material of chromium in freeze-dried human urine in this research met the national certified reference material requirements and could be used for the quality control of the detection of chromium in laboratory human urine.