Extractable organic compounds in midwest rain and snow

Abstract

A portion of the organic compounds in subaqueous sediments originates from airborne materials transported from distant sources. We have analyzed by GC and GC-MS the organic compounds extractable with dichloromethane in rain and snow samples collected over an 8-month period in southern Indiana. Straightchain fatty acids and hydrocarbons from biological sources dominate the compositions and these show only minor seasonal changes. Concentrations of organic compounds appear to be inversely related to volume of precipitation. Much of this organic material appears to have been transported from afar, although local inputs are evident. Estimated flux rates to sediments are small compared to organic matter accumulation rates in Lake Michigan.