Determination of Pyridinium Ionic Liquid Cations by Reversed Phase Ion-Pair Chromatography Using Gradient Elution

Abstract

Four pyridinium ionic liquid cations (N-ethylpyridinium, N-butyl-pyridinium, N-butyl-4-methyl-pyridinium, N-hexyl-pyridinium) were separated and determined by reversed phase ion-pair chromatography with ultraviolet-visible detection. The effects of ion-pair reagent, acetonitrile concentration and column temperature on the retention and separation of the cations were evaluated. Then the four pyridinium cations could be separated at baseline within 13 min. The detection limits (S/N = 3) were 0.30-0.70 mg L -1 , and relative standard deviations (n = 5) for peak areas were 0.18-0.58%. The method was applied to analyze surface water with recoveries of 99.5-104.0%, which is accurate, reliable and practical.

Determination of ionic liquid cations in soil samples by ultrasound-assisted solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry

“…The LODs and LOQs of the 23 ILs in the soil samples were in the range of 0.15-2.88 ng g À1 and 0.50-9.50 ng g À1 , respectively. Compared to the previous studies, the LODs achieved in the present method were lower than those of conventional IC, 24-27 HPLC, 28,29,34,45 and CE. 38,39 These results indicated that the present method was an efficient and sensitive method for the determination of trace amounts of ILs.…”

“…To date, many methods have been developed for IL cation determination, such as ion chromatography (IC), [24][25][26][27] ion-pair chromatography (IPC), 28,29 reversed phase liquid chromatography (RPLC), [30][31][32][33][34] hydrophilic interaction liquid chromatography (HILIC), 35,36 ultra-performance liquid chromatography (UPLC), 37 capillary electrophoresis (CE), 38,39 and capillary isotachophoresis (CITP). 40 Among them, Stepnowski's group has carried out extensive work, and developed a number of analytical methods for the determination of IL cations and anions.…”

“…42 Liquid chromatography (LC) is the most common technique for the determination of IL cations based on various separation modes (IPC, RPLC, HILIC, UPLC). [28][29][30][31][32][33][34][35][36][37][43][44][45] However, these studies are unsuitable for multiple IL analysis due to the clear limitations of retention and selectivity associated with the separation of short alkyl chain compounds. 36 LC-MS is appropriate as it does not require prior separation of the ILs and the mass spectra are fairly simple and provide positive identication of the ions.…”

Chromatographic Techniques in the Research Area of Lithium Ion Batteries: Current State-of-the-Art

“…Four pyridinium IL cations (N-ethyl-pyridinium, N-butyl-pyridinium, N-butyl-4-methylpyridinium, N-hexyl-pyridinium) were separated and determined by reversed phase ion-pair chromatography with ultraviolet-visible detection by Meng et al [141]. As in previous studies, the influence of the retention time was intensively investigated.…”

Determination of long-chained alkylimidazolium ionic liquids based on the hypochromic effect

“…3,4 Imidazolium or pyridinium cations were separated by a gradient elution procedure and determined by IC. 5,6 It has been reported that ion chromatography also can be used to determine ionic liquid anions. 7,8 With a monolithic column, the ion-pair chromatography for analysis of imidazolium cations was developed.…”