Reversed-phase ion-pair chromatography of hydroxyl functionalized imidazolium ionic liquid cations and its application in analysis of environmental water and measurement of hydrophobicity constants
Analysis of alkyl ammonium ionic liquid cations in environmental water by the reversed phase ion-pair SPE combined with HILIC-IUV. (a) The chromatogram of alkyl ammonium cations; (b) the chromatogram of alkyl ammonium cations after enrichment.
Hydrophilic sulfur sols prepared by reaction of aqueous sulfide and sulfite at low pH have been studied by chemical analysis, ion-pair chromatography, and reversed-phase HPLC. The approximate composition of the sol is x(NaHSO4/Na2SO4) ·ySn · zNa2SmO6 with n = 6-10 and m = 4-16. The elemental sulfur Sn accounts for 17% and the polythionate sulfur for 10% of the dry weight (sulfate: 18%). On aging of the sol at 20°C the long-chain polythionates decompose to elemental sulfur and tetrathionate as well as pentathionate. The higher chemical reactivity of this sol compared to S8 is explained by the fact that 45% of the zero oxidation state sulfur (S°) are present as non-S8 molecules.
A novel assay for cytosolic 3-hydroxy-3-methylglutaryl-coenzyme A synthase activity using reversed-phase ion-pair chromatography: demonstration that Lifibrol (K12.148) modulates the enzyme activity.