Direct VOC Analysis of Water-Based Coatings By Gas Chromatography and Solid-Phase Microextraction

By Albert C. Censullo, Dane R. Jones, Max T. Wills

Solvents in water-based coatings may be determined by sampling the coating head space using solid phase microextraction and gas chromatographing the extract. Several water-based coatings of known composition were analyzed by direct capillary gas chromatography and excellent agreement with theoretical VOC values was obtained.

Fifty-two water-based architectural and industrial maintenance coatings were analyzed by a combination of SPME/GC and direct GC of solutions in methanol or dimethyl-formamide and the results compared with reported values.

The SPME/GC method appears to be especially suitable for the analysis of low VOC content water-based coatings, for which EPA Method 24 often gives poor results. The identification and quantitation of exempt solvents may be performed easily with this method. Residual solvent in dried paint films may be determined by SPME/GC.