GAS-CHROMATOGRAPHIC RETENTION INDEX SYSTEM FOR POLYCHLORINATED-BIPHENYLS - POSSIBILITIES AND LIMITATIONS

The identification of individual polychlorinated biphenyls (PCBs) cong eners would be easier if a proper reference series were available to c alculate retention indices when using electron capture detectors, whic h are insensitive to the n-alkanes. In a previous work, a mixture of P CBs showing a linear dependence of retention on the number of chlorine atoms in both isothermal and programmed temperature analysis was sugg ested for reference purposes. Retention index values referred to this series, I-PCB, can be calculated and used for identification. In this work a wide collection of columns was tested in order to check the lin earity of the proposed reference series. The effect of the initial tem perature and heating rate of the programmed runs on the reproducibilit y of the results was investigated. Retention data of the congeners bel onging to the reference series are given together with retention indic es of toxic PCB congeners calculated for various columns. The inversio n of the elution order or the shift of retention values on columns of different polarities are shown. (C) 1997 Elsevier Science B.V.