不同前处理方法对ICP-MS测定尿碘的影响

The effects of different pretreatment methods on the determination of iodine in urine by inductively coupled plasma-mass spectrometry

目的:比较碱和酸提取对ICP-MS测定尿碘的影响以及乙醇的增敏效应。方法:分别用四甲基氢氧化铵和浓硝酸对尿液中的碘进行提取,提取液中加入一定量的乙醇,用ICP-MS测定其中碘浓度。结果:用四甲基氢氧化铵前处理测得尿碘的回收率为98%～108%;用浓硝酸前处理的回收率为106%～114%;体积分数为4%的乙醇能将碘的信号值提高2.2倍。结论:四甲基氢氧化铵和浓硝酸两种提取方法均适合尿碘的测定;乙醇对碘的信号有增敏作用。

The effects of alkali and acid extraction on the determination of iodine in urinary by ICPMS were compared and the sensitization effects on iodine signal when ethanol was added in samples were investigated.Iodine in the urine was extracted with tetramethylammonium hydroxide and nitric acid,respectively.Then the concentration of iodine in the extract liquor was determined by ICP-MS.The recoveries of urinary iodine were in the range of 98%-108% by tetramethylammonium hydroxide extraction while the recoveries were within 106%-114% by nitric acid extraction.Moreover,the signal intensity of iodine increased by 2.2 times through the addition of 4%（V/V）ethanol.The methods of tetramethylammonium hydroxide and nitric acid extraction are suitable for the determination of urine iodine.Ethanol has a sensitizing effect on the iodine signal.