离子色谱法测定三氟甲烷磺酸钾中的阴阳离子

Determination of Anions and Cations in Potassium Trifluor omethanesulfonate by Ion Chromatography

为了确立三氟甲烷酸钾的纯化度、离子种类、杂质种类及含量，建立了离子色谱法电导检测三氟甲烷磺酸钾中阴阳离子的方法。色谱条件：（1）阴离子，SH．AC．1阴离子交换柱（4．0mm×250．0mm）和SH—AC-1阴离子保护柱（4．0mm×50．0mm），1．8mmol碳酸钠／1．7mmol碳酸氢钠加5％乙腈等度淋洗，流速1．0mlMmin，外加水抑制型电导检测；（2）阳离子，SH—CC-1阳离子交换柱（4．0mm×100．0mm）和SH．CC-1阳离子保护柱（4．0him×50．0mm），3．0mmol甲烷磺酸等度淋洗，流速1．0mlMmin，直接电导检测；试样经稀释-定倍数后分别直接分析。对三氟甲烷磺酸钾中F-，Cl-，SO42-，CF3SO-，Na＋，K＋的检出限（S／N=3）从0．0011mg／L到0．0458mg／L；线性相关系数为0．9990～0．9997，RSD值小于4％，加标回收率在98．9％～110．0％。本方法用于实际试样的检测，效果令人满意。

An ion chromatography method based on conductivity measurement was established to detect anions and cations in potassium trifluoromethanesulfonate, and the proper conditions for chromatographic measurements were determined. It was suggested that the separation and determination of anions conducted with SH-AC-1 anion exchange column( 4. 0 mm × 250. 0 mm) and SH-AC-1 anion guard column( 4. 0 mm × 50. 0 mm) while the mixture of 1. 8 mmol Na 2 CO 3 /1. 7 mmol NaHCO 3 and 5% CH 3 CN with a flow rate of 1. 0 mL / min was used as the isocratic eluent in combination with the measurement of external water suppressed conductivity. As to cations,it was suggested to adopt SH-CC-1 cation exchange column( 4. 0 mm × 100. 0 mm) and SH-CC-1 cation guard column( 4. 0 mm × 50. 0 mm) while 3. 0 mmol methane sulfonic acid with as flow rate of 1. 0 mL / min was used as the isocratic eluent in combination with direct monitor of conductivity. After being properly diluted,the samples could be directly measured with the established ion chromatography method. The detection limits( S / N = 3) for F-,Cl-,SO2- 4,CF 3 SO- 3,Na+, and K+in potassium trifluoromethanesulfonate were in the range of 0. 001 1 ~ 0. 045 8 mg / L,the linear coefficients were in the range of 0. 999 0 ~ 0. 999 7,the relative standard deviation was below 4%, and the recoveries upon standard addition were ranged between 98. 9% ~ 110. 0%. In general,the established method could be well adopted to detect actual samples,giving satisfactory determination results.