PREPARATION AND CERTIFICATION OF SOLUTIONS OF PERDEUTERATED POLYCYCLIC AROMATIC-COMPOUNDS INTENDED FOR USE AS SURROGATE INTERNAL STANDARDS

Two standard solutions of deuterated polycyclic aromatic compounds (PA Cs) have been prepared for use as surrogate internal standards. Soluti on DPAC-1 contains 21 deuterated PACs, and is intended for use with ma ss spectrometric (MS) detection. Most of the difficulties in certifyin g concentrations in DPAC-1 arose from the fact that none of the indivi dual compounds was 100% deuterated, so that effects of mass spectromet ric fragmentation are convoluted with those of isotopic distributions. The best methods are discussed for using such internal standards so a s to minimize these problems, together with those arising from kinetic isotope effects. Solution DPAC-2 contains 6 deuterated PACs, and is p rimarily intended for use with reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection (FLD, dual programme d wavelength mode), in which the signals for analyte and internal stan dard are separated chromatographically rather than via the detector. F ull details of the preparation of these solutions are described. In ad dition, examples of their use in the analysis of a certified coal-tar extract (NIST SRM 1597) are described briefly. In one example a novel HPLC-MS technique was employed, and in the other the HPLC-FLD techniqu e was used.