不同消化方式的尿碘低砷量法测定碘含量的实验研究

Experimental research of different digestion ways on Urinary iodine measurement results with method of low arsenic

目的:研究尿碘低砷量法用不同消化方式对尿碘测定结果的影响,进一步验证尿碘低砷量法,为该方法的应用提供支持,以期能提供更适用于基层实验室的尿碘检测方法。方法:用2012年修订的尿碘测定方法(简称尿碘低砷量法,检测范围0~300μg/L)平行测定10管空白样、两种浓度的标准物质(GBW09108l,GBW09110n)及20份成人任意一次尿样,分别用尿碘消解仪和电热恒温干燥箱消化试样,分析其线性相关及范围、检出限、精密度和准确度,并对比两种消化方式测定结果的差异。结果:在两种消化方式下,尿碘低砷量法的碘浓度与相应的吸光度对数值均呈线性相关(r>0.999,相关系数范围:-0.9993^-0.99991);检出限:消解仪组为7.5μg/L,恒温干燥箱组为2.1μg/L;测定低、中、高3种碘浓度的尿样,尿碘值变异系数:消解仪组分别为2.6%、3.7%、1.4%,干燥箱组分别为3.6%、1.6%、2.6%,均小于5%,差异均无统计学意义;测定低、高两种标准物质,相对偏差为:消解仪组为-1.3%、0.05%,干燥箱组为-8.1%、-2.4%,除低浓度组外,差异无统计学意义;两种消化方式消化20份尿样,检测结果差异具有统计学意义,但在实际应用中,这种差异可以认为在允许范围内。结论:该尿碘低砷量法(检测范围0~300μg/L)具有良好的精密度和准确度,基层实验室在检测大批量样品或缺少消解仪的情况下,可以用恒温干燥箱代替。

Objective： To study the effects of sample digestion ways on measurement results of urinary iodine by modified method low arsenic for Urinary iodine determination, and to verify the application value of a modified method, provide more suitable for the primary laboratory urine iodine measurement methods. Methods： Iodine calibration curves of 0 - 300 μg/L, was prepared, and adults urinary iodine was determined by the modified low arsenic method, and digested with heating block and drying oven , Lyophilized human urinary iodine ingredient standard materials were used to analysis [inearity and range, limit of detection, precision and accuracy of this improved detection method. Results： The linear correlative coefficients of modified method of low arsenic were above 0.999 （the range of correlative coefficients were -0.9993- -0.99991 ）. Limit of detection： heating block group was 7.5 μg/L, and drying oven group was 2.1μg/L,; The coefficients of variation （CV）were 2.6% ,3.7% and 1.4 %heating block group （ n = 6） ,and3.6% ,1.6% and 2.6 % in drying oven group when measuring different urine samples with quantitative iodine added, there were no statistical significant difference. The measurement results of two standard materials were all within the given range and the relevant deviations [ RSD] were - 1.3 % and 0.05 % in heating block group （ n = 6 ）, and - 8.1% and - 2.4 % in drying oven group, respectively. The measurement results of adults urine samples between groups shows that the difference was significant （ P 〈 0.01 ） but not produce important differences in practical application. Conclusions： This modified method of low arsenic （0 - 300 /μg/L calibration range） is easier to operate with better precision and accuracy. Drying oven can be used alternatively when heating block is absent or detection of large samples in primary laboratory.