Synthesis and properties of mercaptosilicone modified by Ni(II) and Co(II) as stationary phases for capillary complexation gas chromatography Original Research Article

The synthesis of liquid stationary phases with mercaptopropylmethyl polysiloxane containing cations of Ni2+ or Co2+, bonded to the polymer via thiol groups, is described. Columns of 30 m×0.53 mm were coated with these stationary phases (film thickness of 0.5 μm). The columns are thermally stable up to 250°C. The average molecular masses of the prepolymer (805) and the polymer (10 612) were calculated. The Grob test was also performed. Retention factors (k), retention indices (I) and specific retention volumes (Vg) were found for the compounds of McReynolds series. The obtained polysiloxanes were characterised by means of spectroscopic techniques (UV–Vis, IR). The former technique has enabled to confirm the formation of a metal-phase bond, while the other provided information on polysiloxane chain length increase. Concentrations of metals in the phases containing metal complexes (Ni2+/SH – 7.34×10−3; Co2+/SH – 4.52×10−2) were determined by a voltammetric method. The stationary phases prepared were capable of interacting specifically with nucleophilic compounds.