DIRECT MEASUREMENT OF HEXAHYDROPHTHALIC ANHYDRIDE IN WORKPLACE AIR WITH A TRANSPORTABLE FOURIER-TRANSFORM INFRARED SPECTROMETER

A method for direct measurement of hexahydrophthalic anhydride (HHPA) in workplace air by use of a Fourier transform infrared (FTIR) spectro meter was developed. Two visits were made to a plant manufacturing cap acitors where HHPA was used. On the first visit a calibration method w as developed according to what was expected to give the best calibrati on. This was performed by collection of 82 FTIR spectra from the air w hile simultaneously taking samples with a reference method using Amber lite XAD-2 sorbent tubes. On the second visit, two weeks later, the ca libration method was used for prediction of HHPA concentrations (n = 5 2) in air; these were compared with XAD-2 determinations. The predicte d FTIR values as a function of the XAD-2 determinations were used to e valuate some parameters regarding the FTIR method. The limit of detect ion was 120 mu g HHPA/m(3), and the precision at 150 mu g/m(3) was 22% and at 400 mu g/m(3) 8%. When sampling from a pure HHPA atmosphere th e obtained concentration by the FTIR was 103% of that of the XAD-2 tub es. The selection of different analytical parameters for the determina tions are also discussed. The method is a useful tool in fast mappings of exposure levels.