Determination and prediction for vapor pressures of organophosphate flame retardants by gas chromatography

Abstract

Organophosphate flame retardants (OPFRs) are ubiquitous in the environment. To better understand and predict their environmental transport and fate, well-defined physicochemical properties are required. Vapor pressures (P) of 14 OPFRs were estimated as a function of temperature (T) by gas chromatography (GC), while 1,1,1-trichioro-2,2-bis (4-chlorophenyl) ethane (p,p'-DDT) was acted as a reference substance. Their log PGC values and internal energies of phase transfer (△ vapH) ranged from -6.17 to -1.25 and 74.1 kJ/mol to 122 kJ/mol, respectively. Substitution pattern and molar volume (VM) were found to be capable of influencing log PGC values of the OPFRs. The halogenated alkyl-OPFRs had lower log PGC values than aryl-or alkyl-OPFRs. The bigger the molar volume was, the smaller the log PGC value was. In addition, a quantitative structure-property relationship (QSPR) model of log PGC versus different relative retention times (RRTs) was developed with a high cross-validated value (Q2cum) of 0.946, indicating a good predictive ability and stability. Therefore, the log PGC values of the OPFRs without standard substance can be predicted by using their RRTs on different GC columns.