Abstract
A method for direct measurement of hexahydrophthalic anhydride (HHPA) in workplace air by use of a Fourier transform infrared (FTIR) spectrometer was developed. Two visits were made to a plant manufacturing capacitors where HHPA was used. On the first visit a calibration method was developed according to what was expected to give the best calibration. This was performed by collection of 82 FTIR spectra from the air while simultaneously taking samples with a reference method using Amberlite XAD-2 sorbent tubes. On the second visit, two weeks later, the calibration method was used for prediction of HHPA concentrations (n=52) in air; these were compared with XAD-2 determinations. The predicted FTIR values as a function of the XAD-2 determinations were used to evaluate some parameters regarding the FTIR method. The limit of detection was 120 µg HHPA/m3, and the precision at 150 µg/m3 was 22% and at 400 µg/m3 8%. When sampling from a pure HHPA atmosphere the obtained concentration by the FTIR was 103% of that of the XAD-2 tubes. The selection of different analytical parameters for the determinations are also discussed. The method is a useful tool in fast mappings of exposure levels.