Simultaneous Determination Of Anions And Cations In Qarham Salt Lake By Ion Chromatography

The salt lake brine resourses are abundant in Qinghai Qarhan salt lake. And with the development of science and technology, the development and utilization of salt lake resources also greatly promote the development of local economy. The measurement of salt lake brine has currently become the hot topics in the study of analytical chemistry. However, the ion chromatography has some advantage, such as good selectivity, analysis rapidly and simultaneous determination of various ions, which has been used widely in chemical, pharmaceutical, environmental analysis, etc.The paper was mainly introduced simultaneous determination of ions in Qarhan salt lake brine by ion chromatography. The concrete research content is as follows:1. Simultaneous determination of 7 cations in Qarhan salt lake brine by ion chromatographyA method was established for the simultaneous determination of Li+、Na+、K+、Rb+、Cs+、Mg2+ and Ca2+ in Qarhan salt lake brine by ion chromatography. The analytical column Ion Pac CS12 A and guard column Ion Pac CG12 A were adopted with 12mmol/L methyl sulfonic acid as eluent, the flow rate of 1.0m L/min and sample volume of 50μL. Under the optimal chromatographic conditions the detection limits were between 0.0042μg/L and 2.1969μg/L. The relative standard deviation of peak area, peak height and retention time were less than 1.73%, the correlation coefficient of each anions were more than 0.9995 and the recoveries were between 90.62% and 113.54%. This method with simple sample pretreatment and high accuracy can be used for the simultaneous determination of 7 cations in Qarhan salt lake brine.2.Simultaneous determination of 5 inorganic anions in Qarhan salt lake brine by ion chromatographyAn ion chromatographic method with conductivity detection for simultaneous determination of Cl-、Br-、CO32-、SO42- and I- in Qarhan salt lake brine was developed. The simultaneous determination of five anions in brine was implemented through theguard column Ion Pac AG19 and analytical column Ion Pac AS19 with conductivity detection. Under the conditions of 22mmol/L KOH as eluent concentration, 1.0m L/min as eluent flow rate, and 32℃ as the column temperature, the 5 anions can be separated completely within 23 min. The detection limits were between 0.2820μg/L and 5.8007μg/L. The correlation coefficient of each anion was not lower than 0.9998 and the relative standard deviations were less than 1.43%. The average spiked recoveries were between 90.06% and 110.32%. The method can be applied to the simultaneous determination of 5 inorganic anions in Qarhan salt lake brine with good repeatability and high sensitivity.3. Simultaneous determination of 9 anions in salt lake brine by gradient ion chromatographyA method was established for the simultaneous determination of F-、CH3COO-、HCOO-、Cl-、NO2-、Br-、NO3-、SO42- and C2O42- in salt lake brine by gradient ion chromatography. The simultaneous determination of the 9 anions were achieved on the guard column Ion Pac AG19, analytical column Ion Pac AS19 and eluted by gradient hydroxide potassium 4~18mmol/L. Under the conditions of the flow rate of 1.0m L/min, the column temperature of 32℃, the injection volumn of 25μL and the optimum gradient, the 9 anions can be separated completely within 35 min. The detection limits for analytes ranged from 0.6534μg/L to 9.3311μg/L. The correlation coefficient of analytes was more than 0.9992 and the relative standard deviations of peak height, peak area and retention time were 0.16%~3.03%. The average recoveries were 90.00%~111.49%. The method can be applied to the simultaneous determination of 9 anions in salt lake brine with good repeatability, fast and simple.