Comparison and evaluation of copper complex-containing siloxane polymers as stationary phases for capillary gas chromatography

Two metallomesogenic polymers, P-C11CuC18 and P-C11CuC12 consisting of flexible aliphatic side chains with copper carboxylate complexes have been synthesized on the basis of addition reactions with polysiloxane. The applicability of the prepared columns to the analysis of phthalate esters that are of environmental concern was assessed. For preparation of the capillary column with its wall coated with the metallomesogenic polymer, both static and dynamic methods were employed. Factors affecting the retention and the sample selectivity on both columns were examined. A better separation of phthalates was achieved with P-C11CuC18 than P-C11CuC12. The former phase showed a higher solute–solvent interaction than the latter. With static coating, the wall-coated P-C11CuC18 capillary column (15 m×250 μm I.D.) showed that the baseline separation of all 14 phthalates could be achieved within 38 min with high reproducibility. The calibration graphs for phthalate ester determination were linear over the range of 10–625 μg ml−1. The mass detection limits were lower than the ng range based on three times the standard deviation of seven measurements of the lowest peak that could be detected.