Quantitation, detection and measurement precision of organic molecular markers in urban particulate matter from Philadelphia, PA

Organic molecular markers in airborne particulate matter (PM) were analyzed by GC/Ion Trap MS (GC/IT MS). The particulate samples used in the method development were collected as PM₁₀ in metropolitan Philadelphia during 2000. The standard deviation of the five-point calibration relative response factors determined 3 mo apart was < 6.36% for the non-polar markers measured (n-alkanes, PAH, and hopanes) and 23.33 to 31.82% for polar markers (n-alkanoic acids and dicarboxylic acids). Given good documented system stability, it is possible that validation of the RRF for non-polar markers (5 point calibrations) could be monitored at longer intervals (3 months or longer) for compounds other than polar markers. Good analytical precision was found for alkane and hopanes molecular markers using seven pairs of replicate ambient PM samples. The analytical precision was 2.5% for n-octacosane to 8.1% for n-triacontane, with three out of eight n-alkanes producing measurement precision < 5%. The suite of hopanes had measurement precision ranging from 2.6 to 6.1%. The results demonstrated the high sensitivity of the GC/IT MS measurement method with known data quality required by CMB and source-receptor models. This is an abstract of a paper presented at the 98th AWMA Annual Conference and Exhibition (Minneapolis, MN 6/21-24/2005).