离子色谱法与电位滴定法测定采血管中EDTA含量对比研究

Comparison of ion chromatography and potentiometric titration for determination of EDTA content in collection blood tube

为了准确检测出采血管中乙二胺四乙酸(EDTA)的含量,本文拟对离子色谱法和电位滴定法检测EDTA含量的方法学进行对比。离子色谱法以TSK gel Super IC-AZ阴离子交换柱为分离柱,通过抑制电导检测器检测EDTA;电位滴定法以Ca^(2+)选择电极,以0.05 mmol/L Ca^(2+)标准溶液为滴定液,电位突跃法判定滴定终点,记录消耗滴定液的体积,计算EDTA含量。离子色谱法中,采血管中EDTA的质量浓度为1.48 mg/mL,样品平行测定相对标准偏差为0.51%(n=6);当加标样品中EDTA的质量浓度为2.12~30.00 mg/L时,其回收率为104.07%~113.60%;检出限和定量限分别为0.09和0.29 mg/L。电位滴定法中,采血管中EDTA的质量浓度为1.51 mg/mL,样品平行测定相对标准偏差为0.45%(n=6);当加标样品中EDTA的质量浓度为1.89~31.70 mg/L时,其加标回收率为100.16%~100.97%。2种方法均可准确测定采血管中EDTA的含量,离子色谱法可在定量限附近准确测定低浓度EDTA含量,电位滴定法无需标准物校准即可实现采血管中EDTA含量的准确测定。

In order to accurately detect the content of ethylenediamine tetraacetic acid(EDTA)in collection blood tube,this paper intends to compare the methods of ion chromatography and potentiometric titration to detect EDTA content.For ion chromatography,a TSK gel Super IC-AZ anion-exchange column was used as the separation column and EDTA was detected by an inhibitory conductance detector.For potentiometric titration,the Ca^(2+)selective electrode was used,0.05 mmol/L Ca^(2+)standard solution was used as the titration solution,and the titration end point was determined by potential jumping method,the volume of consumed titration solution was recorded and the EDTA content was calculated volume of titration solution consumed.In ion chromatography,the mass concentration of EDTA in collection blood tube was 1.48 mg/mL,and the relative standard deviation of parallel determination was 0.51%(n=6).When the concentration of EDTA was 2.12 to 30.00 mg/L,the recovery was 104.07%to 113.60%,the limits of detection and quantification were 0.09 and 0.29 mg/L,respectively.In potentiometric titration,the mass concentration of EDTA in collection blood tube was 1.51 mg/mL,and the relative standard deviation of parallel determination was 0.45%(n=6);when the concentration of EDTA was 1.89 to 31.70 mg/L,the recoveries were 100.16%to 100.97%.Both methods can accurately determine the content of EDTA in collection blood tube,through the comparison of methodology,ion chromatography can accurately determine the content of low concentration EDTA near its limit of quantitation,and potentiometric titration can accurately determine the content of EDTA in collection blood tube without calibration of standard.