摘要目的 研究样品消化条件对尿碘测定结果的影响,为2012年新修订尿碘测定标准方法的应用提供支持.方法 根据新修订的尿碘测定标准方法,使用3份标准物质[GWB09108k、GWB09109f、GWB09110m,碘含量分别为(68.2±9.0)、(138.0±10.0)、(221.0±10.0)μg/L]、5份尿样(碘含量为100～300 μg/L),对消解液的浓度(0.8 ～ 1.3 mol/L过硫酸铵溶液,每组间隔0.1 mol/L)、消解设备(恒温消解仪和电热干燥箱)以及消化后放置时间(0.5、1.0、2.0、4.0、22.0 h)等条件进行研究.结果 0.9、1.0、1.1 mol/L过硫酸铵消解液3组间测定结果比较差异无统计学意义(P＞ 0.05);恒温消解仪与电热干燥箱消化效果比较,除1份低浓度标准物质(GBW09108k)外,其余标准物质及样品测定结果的差异无统计学意义(P＞0.05);消化后样品放置0.5～ 22.0 h各组间测定结果的差异无统计学意义(P＞0.05).结论 过硫酸铵消解液适宜浓度范围为0.9～1.1 mol/L;消化时推荐使用恒温消解仪,在缺乏时,可使用电热干燥箱替代;消化后的样品放置0.5～ 22 h不影响测定结果.

abstractsObjective To study the effects of sample digestion conditions on measurement results of urinary iodine determined by As(Ⅲ)-Ce4+ catalytic spectrophotometry with ammonium persulfate digestion,and to promote the application of newly revised (the 2012 edition) national standard method for determination of urinary iodine.Methods According to the newly revised national standard method,various digestion conditions,such as ammonium persulfate concentration (0.8-1.3 mol/L,group interval 0.1),digestion instruments (heating block and drying oven) and standing time after digestion(0.5,1.0,2.0,4.0 and 22.0 h),were studied.The samples included 3 standard materials,which were GWB09108k,GWB09109f and GWB09110m containing iodine of (68.2 ± 9.0),(138.0 ± 10.0) and (221.0 ± 10.0) μg/L,and 5 urine samples with iodine concentration of 100-300 μg/L.Results Measurement results among the three groups of 0.9,1.0 and 1.1 mol/L ammonium persulfate digestion fluid showed no significant difference(P ＞ 0.05).The digestive effect showed no significant difference between heating block and drying oven (P ＞ 0.05) except one standard material in low concentration (GBW09108k).After digestion,samples were placed 0.5-22.0 h,the measurement results between groups showed no significant difference (P ＞ 0.05).Conclusions Appropriate concentrations of ammonium persulfate are from 0.9 mol/L to 1.1 mol/L.Heating block is recommended for the digestion,however,when absent,drying oven can be used alternatively.The standing times from 0.5 h to 22 h after digestion have not affected the measurement results.