Sampling artifact estimates for alkanes, hopanes, and aliphatic carboxylic acids

• Published in: Atmospheric environment (1994) 2005-12, Vol.39 (37), p.6945-6956
• Main Authors: Sihabut, Tanasri, Ray, Joshua, Northcross, Amanda, McDow, Stephen R.
• Format: Article
• Language: English
• Subjects: Analysis methods; Applied sciences; Atmospheric pollution; Carboxylic acids; Exact sciences and technology; GCMS; Hopanes; n-alkanes; Organic aerosol; Pollution; Sampling artifact
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2005.02.053

Sampling artifacts for molecular markers from organic speciation of particulate matter were investigated by analyzing forty-one samples collected in Philadelphia as a part of the Northeast Oxidant and Particulate Study (NEOPS). Samples were collected using a high volume sampler with two quartz fiber filters in series. n-Alkanes (C23–C31), hopanes (C27–C31), and n-alkanoic acids (C10–C22) were analyzed by gas chromatography-mass spectrometry (GCMS). The extent of artifact error was dependent on vapor pressure and species concentration. Particulate organic species are classified into the following three categories: (1) the amount collected on the backup filter was often a large fraction of the amount collected on the front filters ( n-alkanes C23 and C24, n-carboxylic acids C10–C14); (2) the amount collected on the backup filter was consistently a small fraction of the amount collected on the front filter ( n-alkanes C25–C28, hopanes C27–C30, n-carboxylic acids C15–C18, and dicarboxylic acids C3–C9); (3) the species was rarely observed on backup filters ( n-alkanes C29–C31, hopanes C31 and C32).