阀切换-离子色谱法测定天然气水合物试采产出水中的氯离子和硫酸根

Determination of chloride ion and sulfate in glycol-containing water produced from gas hydrate trial production by valve-switching-ion chromatography

建立了阀切换-离子色谱测定天然气水合物试采含乙二醇产出水中氯离子、硫酸根的方法,采用ICS5000+双通道离子色谱系统,配制双六通阀系统,以Dionex TM IonPac TM UTAC-ULP1超痕量阴离子浓缩柱为捕获柱,对将氯离子、硫酸根进行在线捕获,再以超纯水将流路中的乙二醇溶液冲洗至废液,达到在线去除乙二醇的目的。分析柱为Dionex IonPac AS18-Fast阴离子色谱柱,选择25.5mmol/L的氢氧化钠溶液为淋洗液对氯离子、硫酸根进行了定量分析,在上述色谱条件下,氯离子和硫酸根能够很好的分离,在0~100 mg/L浓度范围内线性关系良好,相关系数分别为0.9996和0.9993,检出限分别为0.0085mg/L和0.0214mg/L,回收率分别为96.8%~100.6%和99.1%~101.2%,相对标准偏差均小于2%。该方法简便、快速、准确,可应用于天然气水合物试采产出水等含水溶性有机物样品的分析。

Using the double six-way valve ICS5000+ion chromatography system and ultra trace anion concentration column(Dionex TM IonPac TM UTAC-ULP1)as capture column,the chloride ion and sulfate are captured online,and then the glycol solution in flow path is washed to waste liquid with ultra pure water.The analytical column is Dionex IonPac AS18-Fast anion chromatographic column.25.5 mmol/L sodium hydroxide solution is selected as eluent for quantitative analysis of chloride and sulfate.Under the above chromatographic conditions,chloride ion and sulfate are well separated,and the linear relationship is good in the concentration range of 0-100 mg/L.The correlation coefficients are 0.9996 and 0.9993,respectively.The detection limits are 0.0085 mg/L and 0.0214 mg/L,respectively.The recovery rates are 96.8%-100.6% and 99.1%-101.2%,respectively.The relative standard deviations are less than 2%.The method is simple,rapid and accurate.