Recertification of standard reference material (SRM) 1649, urban dust, forthe determination of polycyclic aromatic hydrocarbons (PAHs)

The National Institute of Standards and Technology (NIST) recently issued S RM 1649a, Urban Dust, with certified and reference values for 44 polycyclic aromatic hydrocarbons (PAHs). This material is a recertification of SRM 16 49 which was issued in 1982 with certified values for only five PAHs. The P AHs were determined using the following analytical techniques: (1) reversed -phase liquid chromatography with fluorescence detection (LC-FL) for analys is of the total PAH fraction, (2) reversed-phase LC-FL for analysis of isom eric PAH fractions isolated by normal-phase LC (i.e., multidimensional LC), and (3) gas chromatography/mass spectrometry (GC/MS) for analysis of the P AH fraction using three different stationary phases, each with different se lectivity for PAH separations. The results from the different techniques ar e compared and discussed. SRM 1649a is currently the most extensively chara cterized environmental matrix SRM with respect to PAH constituents.