Ambient concentrations and measurement precision of molecular markers in fine particles from Philadelphia, Pennsylvania

The adverse environmental and health effects of organic components in fine particles have been recognized by the public. The present study provides an improved analytical strategy for analyzing organic components in fine particles and knowledge of the measurement precision. Both are of particular importance for locating pollutant sources and investigating the potential health effects associated with fine particles. In this study, the ambient concentrations of major organic molecular source markers in fine particles collected in Philadelphia, PA 2000 were measured, including n-alkanes, PAH, hopanes, n-alkanoic acids and dicarboxylic acids. The measurements were performed with a gas chromatography/mass spectrometry following a developed analytical method and quality assurance plan and the precision of the measurements was carefully investigated. The ambient concentrations of the molecular markers vary from day to day and season to season by their unique patterns. Understanding of these interesting variations needs further survey on emission source inventory, meteorological measurements and source apportionment modeling in Philadelphia.