The sampling and determination of azelaic acid in air.

Air samples of azelaic acid (nonanedioic acid), were collected on polyvinyl chloride (PVC) filters, extracted with ethanol, derivatized with N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), containing 1% trimethylchlorosilane (TMCS) and analyzed by gas-liquid chromatography. The esterification product is the trimethylsilyl ester, which is different from the methyl ester usually chosen in the esterification processes. A calibration curve was used to determine the azelaic acid content in the filter samples. The detection limit was 1 microgram per sample. Results indicate that the analytical method can be applied to other monocarboxylic and dicarboxylic acids.