整体柱离子对色谱-间接紫外检测法快速测定N-甲基,丙基吗啉阳离子

建立了快速分析无紫外吸收的N-甲基,丙基吗啉阳离子的离子对色谱-间接紫外检测法。采用反相C18硅胶整体柱,以背景紫外吸收试剂-离子对试剂-有机溶剂为流动相。研究了背景紫外吸收试剂、检测波长、离子对试剂、有机溶剂、柱温、流速对吗啉阳离子测定的影响。最佳色谱条件为:(0.5 mmol/L对氨基苯酚盐酸盐-0.1 mmol/L庚烷磺酸钠)溶液-甲醇(9:1, v/v)为流动相,检测波长230 nm,柱温30 ℃,流速1.0 mL/min。在此条件下,N-甲基,丙基吗啉阳离子的保留时间为2.966 min,检出限为0.07 mg/L(S/N=3),峰面积的相对标准偏差为2.1%(n=5),保留时间的相对标准偏差为0.02%(n=5)。将此方法用于分析实验室合成的N-甲基,丙基吗啉离子液体,加标回收率为98.8%。结果表明本方法简便、快速。

Rapid determination of N-methyl,propyl-morpholinium cation by ion-pair chromatography on monolithic column with indirect ultraviolet detection

A fast analytical method was developed for the determination of N-methyl,propyl-morpholinium cation (MPMo) without UV absorption group by ion-pair chromatography-indirect UV detection. Chromatographic separation was performed on a reversed-phase silica-based monolithic column using background UV absorption reagent aqueous solution-ion-pair reagent aqueous solution-organic solvent as the mobile phase. The effects of the background UV absorption reagent, detection wavelength, ion-pair reagent, organic solvent, column temperature and flow rate on the determination of MPMo were investigated. It was found that the morpholinium cation could be determined well with (0.5 mmol/L 4-aminophenol hydrochloride-0.1 mmol/L 1-heptanesulfonic sodium) aqueous solution-methanol (9:1, v/v) as mobile phase at the UV detection wavelength of 230 nm, the column temperature of 30 ℃ and the flow rate of 1.0 mL/min. Under these conditions, the retention time of MPMo was 2.966 min. The limit of detection for MPMo was 0.07 mg/L (S/N=3). The relative standard deviations (n=5) for the peak area and retention time were 2.1% and 0.02%, respectively. The method was successfully applied to the determination of morpholinium ionic liquid synthesized by a chemistry laboratory. Recovery of MPMo after spiking was 98.8%. The results showed that this method is simple and rapid.