目的建立微量尿碘的低砷铈催化分光光度测定法,减少废液砷对环境的污染,批量测定微量尿碘。方法以过硫酸铵消化.砷铈催化分光光度法测定尿碘的原理为基础,96微孔板作为消化、催化反应容器.恒温烘箱作为消化加热工具,冰板降温,利用酶标仪测定吸光度值。建立微量尿碘低砷铈催化分光光度测定法(以下简称新方法)。分析新方法性能(包括检出限实验、精密度实验、尿碘标准物测定、样品加标回收实验),并用新方法与我国尿碘定量检测的标准方法[《尿中碘的砷铈催化分光光度测定方法》(ws/T107.2006),以下简称标准法]同时测定24份人尿样(高、中、低碘含量尿样各8份),将尿碘结果进行对比分析,验证新方法的准确度。结果新方法检测尿碘线性范围为0—300μg/L;标准尿碘含量与测得吸光度值的对数之间相关系数(r)≥0.999;检出限为8.67μg/L;高、中、低碘含量尿样检测值变异系数(CV)分别为2.15%、4.33%、3.48%;高、中、低碘含量标准物质检测值相对偏差(RD)分别为-0.16%、1.81%、-2.82%;低碘含量尿样加标回收率为97.51%,高碘含量尿样加标回收率为96.01%。新方法与标准法检测尿碘结果有统计学相关性(r=0.995,P〈0.05)。结论新方法明显减少废液含砷量,降低环境污染,试剂用量节省,操作简便快捷,结果准确可靠,适合作为微量尿碘批量测试的补充方法推广。
Objective To introduce a new economical method which can be used for determination of urinary iodine of batch samples with low cost of arsenic trioxide, and decrease environmental pollution. Methods A catalytic spectrophotometry for measuring iodine content in a small volume of urine samples with low cost of arsenic and cerium was established based on the principle of ammonium persulfate digestion As3+-Ce4+catalytic spectrophotometry. Ninety-six well polypropylene microplate was utilized as digestion and catalysis reaction vessel, conventional laboratory oven was used as a tool to digest and heat, ice plate was used to cool, and the absorbance was read with the Multimode Reader. The accuracy of the new method was evaluated with the current standard method (WS/T 107-2006) by simultaneous determination of urinary iodine of 24 urine samples. Results The linear range of this method was 0 - 300 μg/L, the linear correlative coefficient (r) was higher than 0.999, and the detection limit was 8.67 μg/L. The coefficient of variations was 2.15%, 4.33% and 3.48% when measuring urine samples with high, medium and low iodine concentration, respectively. The test results of three national standard urinary iodine samples were all within the given value range and the relative deviation (RD) was - 0.16%, 1.81% and - 2.82%, respectively. The average recovery of the low concentration was 97.51%, and that of the high concentration was 96.01%. The two methods correlated well (r = 0.995, P 〈 0.01). Conclusions This method greatly reduces the arsenic waste, environmental pollution, consumables and labor. The new method is simple and efficient, accurate and reliable; it is suitable for application as a supplementary method for analyzing urinary iodine of a large number of samples.