Analysis of Organic Pollutants by Micro Scale Liquid-Liquid Extraction and On-column Large Volume Injection Gas Chromatography

Abstract

The analysis of organic pollutants in water is traditionally done following EPA procedures which commonly use liquid-liquid extraction. One liter of water is extracted three times with 60 mL of an organic solvent. The extract is concentrated and analyzed by gas chromatography. This procedure is time consuming and can cause losses of semi-volatile components, in addition to requiring a relatively large amount of organic solvent (180 mL). By performing the extraction directly in a GC autosampler vial using one milliliter of contaminated water and one milliliter of organic solvent, then injecting a large volume (~150 mL) of the organic layer taken directly from the vial by an autosampler, the same analysis can be done simpler, quicker, and with much less organic solvent (1 mL).