梯度淋洗离子色谱法同时分离测定盐湖卤水中的阴离子

Simultaneous separation and determination of nine anions in salt lake brine by gradient ion chromatography

为了分离盐湖卤水中的阴离子并测定它们的含量,采用Ion Pac AG19型保护柱及Ion Pac AS19型分离柱、4~18 mmol/L氢氧化钾溶液梯度淋洗、电导检测器检测,在流速为1.0 m L/min、柱温32℃、进样量25μL和最佳梯度淋洗液条件下,6种无机阴离子和3种有机酸根离子在35 min实现完全分离,各离子检出限为0.65~9.33μg/L,相关系数r2≧99.9437%,峰高、峰面积及保留时间的相对标准偏差RSD(n=9)为0.157%~3.027%,盐湖卤水样品测定各离子的平均加标回收率为90.00%~111.49%,样品离子测定RSD(n=5)均小于4.60%。建立了梯度淋洗/离子色谱方法,同时分离测定盐湖卤水中6种无机阴离子F^-,Cl^-,NO_2^-,Br^-,NO_^(3-),SO2_4^-和3种有机酸根离子CH_3COO^-,HCOO^-和C_2O_4^(2-)的含量。该方法重复性好、快速、简单,可用于盐湖卤水中6种无机阴离子和3种有机酸根离子的同时分离测定。

In order to separate anions in saline lake brine and determine their contents,the simultaneous separation and determination of the nine anions were achieved on the guard column Ion Pac AG19 and analytical column Ion Pac AS19 with conductivity detection and eluted by gradient potassium hydroxide（ 4 ~ 18 mmol / L）. Under the conditions of the flow rate of 1. 0m L / min,the column temperature of 32℃,the injection volume of 25 μL and the optimum gradient,the nine anions can be separated completely within 35 min. The detection limits ranged from 0. 65 μg / L to 9. 33 μg / L.The correlation coefficient of analyses were greater than 99. 943 7% and the relative standard deviations（ RSD） of peak height,peak area and retention time were 0. 157% ~ 3. 027%（ n = 9）. The average recoveries of analysts in salt lake brine were 90. 00% ~ 111. 49% and the RSD were less than 4. 60%（ n = 5）. A method was established for the simultaneous separation and determination of 9 anions F-,CH_3COO^-,HCOO^-,Cl^-,NO_2^-,Br^-,NO_3^-,SO2-4and C2O2-4in salt lake brine by gradient ion chromatography. The method can be applied to the simultaneous separation and determination of F-,CH_3COO^-,HCOO^-,Cl^-,NO-2,Br^-,NO-3,SO2-4and C_2O_4^（2-）in salt lake brine with good repeatability,fast and simple.