Separation and indirect ultraviolet detection of ferrous and trivalent iron ions by using ionic liquids in ion chromatography

Abstract

A method of simultaneous separation and indirect ultraviolet detection of different valence iron ions Fe2+ and Fe3+ by using ionic liquids as mobile phase additives and ultraviolet absorption reagents on a cation exchange column functionalized with carboxylic acid group was developed. The effects of ionic liquids, organic acids, detection wavelength, etc. on separation and detection of Fe2+ and Fe3+ were investigated and the mechanism was discussed. The pyridinium and imidazolium ionic liquids were not only ultraviolet absorption reagents of indirect ultraviolet detection but also effective components for separating Fe2+ and Fe3+. The separation and detection of Fe2+ and Fe3+ can be achieved using 0.5 mmol/L pyridinium ionic liquid−1.2 mmol/L methanesulfonic acid as the mobile phase. The determination of Fe2+ and Fe3+ had a good linear relationship in the concentration range of 1−100 mg/L. The limits of detection of Fe2+ and Fe3+ were 0.12 and 0.09 mg/L, respectively. This method was applied to the actual sample detection in the field of medical analysis. The spiked recoveries were between 97.3 and 99.5%, and the relative standard deviations were less than 0.6%. The method is simple, accurate, and reliable, and is an analytical method with universal and practical value.

Simultaneous separation and indirect ultraviolet detection of chlorate and perchlorate by pyridinium ionic liquids in reversed‐phase liquid chromatography

“…As new green solvent, ILs have been widely used in extraction, organic synthesis, catalysis, analytical chemistry, and other fields [10][11][12][13][14][15][16][17]. In the field of chromatographic analysis, ILs are used to enantioseparation in CE [18], stationary phases for GC [19] and LC [20], and mobile phase additives for LC [21][22][23]. The analytes using ILs as mobile phase additives are mainly organic compounds [24][25][26][27][28][29][30][31][32].…”