Methodology for Sampling and Analysis of Lipids in Aerosols from the Remote Marine Atmosphere

摘要

A procedure is described for the collection of remote marine aerosol samples by high-volume filtration, cascade impaction, dry fallout collection and rain. Samples were analyzed quantitatively for five classes of naturally occurring lipids (n-alkanes, wax esters, fatty alcohols, sterols, and fatty acids) and polycyclic aromatic hydrocarbons (PAHs). Air samples (4,000-10,000 cu m) were collected on glass fiber filters under automatic control. Rain samples of 1-5 L were collected on an event basis. Filters and rain samples were extracted with methylene chloride. The extracts were fractionated into discrete chemical classes by silica-gel absorption chromatography. The fractions were derivatized if necessary and analyzed by HRGC and HRGC/MS. A second filter extraction was required for fatty acid salt analysis. Internal standards were used to quantify recoveries and concentrations. Typical blanks and concentrations for remote marine aerosol and rain samples are described and compared with other methods used in coastal marine, rural and suburban sampling locations.