Some observations on the effect of molecular structure upon the determination of the selenium to carbon ratios in various organoselenium compounds using gas chromatography with atomic emission spectrometric detection

The performance of a commercially available gas chromatograph employing an atomic emission detector has been evaluated with respect to analytical figures of merit and the determination of selenium to carbon ratios using a series of asymmetric and symmetric diorganyl diselenides and selenides. Three selenium atomic emission lines, at 196.09, 203.98 and 216.42 nm, were employed during the study. A temporally resolved secondary emission phenomenon was observed near the 196.09 nm line which was tentatively attributed to molecular emission from SeO. This emission impaired the analytical performance of the 196.09 nm atomic emission line, with the best overall figures of merit being achieved at 203.98 nm. The accuracy of the selenium to carbon ratios was found to be adversely effected when the concentration of the analyte varied significantly from that of the reference compound, especially when the Se 196 nm emission line was used. Under optimal conditions, it was found that the accuracy of Se : C ratios could be determined to within ±10% in the majority of cases. The instrumentation was successfully used to separate and identify the products from two separate series of organometallic exchange reactions, the first involving the eight symmetrical diselenides with themselves, and secondly these same diselenides with diphenyl ditelluride.