Determination of gallic acid in wood dust as an indicator of oak content

A high-performance liquid chromatography (HPLC) method was developed for th e detection of extracted gallic acid in wood dust. Gallic acid is a polyphe nol present in carcinogenic oak wood dust, but not in beech, ash, pine or s pruce dusts, as confirmed by HPLC analyses The method involved the extracti on of gallic acid from, the oak dust. followed by liquid chromatographic an alysis. The correlation coefficient for the share of oak dust vs. the galli c acid concentration of wood dust was 0.995. The method was tested with oak wood dust samples collected on polycarbonate membrane filters during an 8 h workshift in a floor board factory, where the dust content of the air sam ples was determined gravimetrically. The oak dust and the gallic acid conce ntrations varied from 0.2 to 13.8 mg m(-3) and from 0.03 to 3.8 mug m(-3), respectively. These parameters were linearly correlated with a correlation coefficient of 0.95 The airborne gallic acid determination is a useful tech nique to confirm occupational exposure to oak wood dust, a recognized human carcinogen.