In this study, an analytical method of hydrophilic interaction liquid chromatography combined with indirect ultraviolet detection for the determination of alkyl ammonium ionic liquid cations was developed, and it was combined with the sample pretreatment technique of solid phase extraction in order to be applied to analysis of alkyl ammonium ionic liquid cations in environmental water. The retention behavior of alkyl ammonium cations on the hydrophilic interaction column had the typical characteristics of hydrophilic interaction liquid chromatography, and their retention followed the carbon number rule. The separation and detection of tetraethyl ammonium cations, tetrapropyl ammonium cations and tetrabutyl ammonium cations were achieved in 20 min by using 1.0 mM 1-ethyl-3-methyl imidazolium trifluoroacetate aqueous solution/acetonitrile (40/60, v/v) as the mobile phase. The detection limits were 0.093, 0.096 and 0.253 mg L⁻¹, respectively. The relative standard deviations of the retention time and the peak area were less than 0.5% from seven determinations. The reversed phase ion-pair solid phase extraction method was realized by using sodium octanesulfonate as the ion-pair reagent and 90% acetonitrile (v/v) solution as the eluent. Alkyl ammonium cations in Songhua River water and Hulan River water were analyzed. The results showed that the recoveries and enrichment effect of tetraethyl ammonium cations and tetrapropyl ammonium cations were all good. The method is simple and reliable, which can provide a reference for the analysis of alkyl ammonium cations in environmental water.

中文翻译：

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亲水作用液相色谱法测定烷基铵离子液体阳离子及其在环境水分析中的应用†

本研究开发了一种亲水性相互作用液相色谱结合间接紫外检测法测定烷基铵离子液体阳离子的分析方法，并将其与固相萃取的样品预处理技术相结合，以便用于分析环境水中的烷基铵离子液体阳离子。烷基铵阳离子在亲水作用柱上的保留行为具有亲水作用液相色谱的典型特征，其保留遵循碳数规则。使用1.0 mM 1-乙基-3-甲基咪唑三氟乙酸盐水溶液/乙腈（40/60，v / v）作为流动相。检出限为0.093、0.096和0.253 mg L^-1。七个测定的保留时间和峰面积的相对标准偏差均小于0.5％。以辛烷磺酸钠为离子对试剂，以90％乙腈（v / v）溶液为洗脱液，实现了反相离子对固相萃取方法。分析了松花江水和呼兰河水的烷基铵阳离子。结果表明，四乙基铵阳离子和四丙基铵阳离子的回收率和富集效果均良好。该方法简便可靠，可为环境水中烷基铵阳离子的分析提供参考。