离子色谱-紫外检测法同时分析碘酸根、碘离子、溴酸根和溴离子

摘要

An analytical method of ion chromatography with ultraviolet detection has been developed and applied for the simultaneous determination of iodate,iodide,bromate and bro-mide. The separation was performed on a quaternary ammonium type anion exchange column with citric acid and acetonitrile as mobile phase. The effects of the detection wavelength,the kind and concentration of the mobile phase and other parameters on separation and detection of the four ions were investigated. The retention rules were studied and the chromatographic con-ditions were optimized. Under the conditions of 210 nm as detection wavelength,0. 9 mL / min as flow rate,40 ℃ as column temperature,and 1. 0 mmol / L citric acid-acetonitrile(85 :15,v /v;pH 5. 0)as mobile phase,the four ions were completely separated and the system peaks and other common anions didn’t interfere with the determination. The detection limits of the four ions(S / N = 3)were 0. 07 - 0. 16 mg / L. The relative standard deviations of the retention times and peak areas obtained by determining samples five times continuously were below 1% . The spiked recoveries of the four anions were from 98. 0% to 102% . This method has been success-fully used to determine ionic liquids synthesized by chemistry laboratory and underground water samples. The results were accurate and reliable.%建立了同时分析碘酸根、碘离子、溴酸根和溴离子的离子色谱-紫外检测分析方法。用季铵型阴离子交换柱，以柠檬酸-乙腈为流动相，采用紫外检测器实现了4种离子的同时分离和检测。研究了检测波长和流动相种类、浓度、pH 值等因素对4种离子分离和测定的影响，探讨了保留规律，优化了色谱分析条件。在检测波长为210 nm、流动相为1.0 mmol / L 柠檬酸-乙腈（85：15，v / v；pH 5.0）、流速为0.9 mL / min、柱温为40℃条件下，4种离子完全分离，且系统峰不干扰测定。4种离子的检出限（S / N =3）为0.07~0.16 mg / L，连续5次进样测定的峰面积和保留时间的相对标准偏差均在1％以下。将此方法用于离子液体样品及地下水样品的分析，结果准确、可靠。