3-戊酮衍生化-气相色谱法快速检测尿碘含量

Determination of iodine in urine by gas chromatography after 3-pentanone derivatization

目的基于气相色谱-电子捕获检测器,建立了一种3-戊酮衍生化快速测定尿碘含量的方法。方法尿样用乙酸锌和亚铁氰化钾沉淀蛋白及杂质,离心后取上清液,加入硫酸和重铬酸钾氧化碘离子,再以3-戊酮衍生化。用正己烷萃取生产的单一衍生化产物,再经HP-5毛细管柱分离后以GC-μECD检测,根据保留时间定性,外标峰面积法定量。结果碘离子浓度为25μg/L^1 000μg/L时,线性关系良好,r=0.999 4,平均加标回收率为95.3%~98.9%,相对标准偏差(RSD)为1.0%~3.1%。本方法的检出限为0.35μg/L,定量下限为1.2μg/L。本方法与国家标准检测方法中的砷铈法比较,差异无统计学意义(P>0.05)。结论本法检测尿碘具有操作简单、快捷、结果准确性高的特点,具有较高的实用性,可以满足尿碘检测的要求。

Objective Based on GC- ECD device,a 3- pentanone derivatization method was developed for rapidly detecting iodine in urine. Methods Protein and other impurities were first precipitated by adding zinc acetate and potassium ferrocyanide in urine samples. After the centrifugation,the supernatant was treated with sulfuric acid and potassium dichromate,and then derivatized with 3- pentanone. The 2- iodopentan- 3- one derivatives were extracted with hexane,and then separated by using HP- 5 capillary column,in the end,iodine can be detected by GC- ECD device. Determination was made with retention time and quantification with external standard method. Results Good linearity was obtained when the concentration of ion was among 25 μg / L- 1000 μg / L（ r = 0. 999 4）. The average recovery rate was among 95. 3%- 98. 9%,and the relative standard deviation（ RSD） was among 1. 0%- 3. 1%. The detection limit for urinary iodine of current assay was 0. 35 μg / L,and the lower limit for quantification was 1. 2 μg / L. It showed no significant difference compared with As- Ce catalysis spectrophotometry（ P〉0. 05）. Conclusion In the determination of urine iodine,this method is operation- simple,fast with accurate results and with high practicability,which can meet the requirements of the detection of urinary iodine.