NaHSO_3溶液中SO_4^(2-)离子色谱峰的分叉现象及其测定

Determination of Sulfate Ion in 30% Sodium Bisulfite Solution by Ion Chromatography

首次发现并探讨了30%(w)亚硫酸氢钠水溶液中硫酸根离子色谱法峰分叉现象。选择0.1%TEA溶液为亚硫酸氢钠稳定剂,分析柱为IonPacAS14,采用丙酮为有机改进剂,确定淋洗液组成为1.5mol/LNa2CO3-3.5mol/L NaHCO3-10%(CH3)2CO,流速为1.0mL/min。抑制电导检测,在线性范围内硫酸根检出限为0.05μg/g,相关系数大于0.999,从而建立了30%亚硫酸氢钠溶液中硫酸钠测定新方法。用于实际样品分析,操作便捷,结果可靠。

Based on the study of the appearance of double_humped chromatographic peak of sulfate ion in30%(w)sodium bisulfite solution,a novel method for the determination of sulfate ion in30%sodium bisulˉfite solution by ion chromatography was developed.It was found that the double_humped chromatographic peak could be turned into a single peak after diluting the30%sodium bisulfite solution at least by a factor of300.The sample was pretreated with0.01%formaldehyde(37%)and0.1%triethanolamine(TEA)solutionto preˉvent the sulfite ion transforming to sulfate ion.A mixed solution of1.5mol/L Na 2 CO 3 ,3.5mol/L NaHCO 3 and10%(CH 3 ) 2 CO was used as eluent with a flowrate of1.0mL/min.The separation column was IonPac AS14.The result was detected by suppressed conductivity.The injection volume was25μLand the detection limit of 2-4 SO was0.05μg/g.The proposed method was simple and rapid and has been successfully applied to the determination of sulfate ion in30%sodium bisulfite samples.