Determination of toluene-2,4-diisocyanate in environmental and workplace air by sampling onto Tenax-TA followed by thermal desorption and capillary gas chromatography using flame ionisation and ion-trap detection

Abstract

This work describes a method for the determination of low levels of toluene-2,4-diisocyanate (TDI) in workplace air. Perkin-Elmer ATD-400 adsorbent tubes containing 200 mg of Tenax-TA (80–100 mesh) were used with low-flow personal sampling pumps. Following a period of sampling, the adsorbent tubes were sealed and returned to the laboratory for analysis within 24 h. The TDI content was determined by thermal desorption of the tubes followed by capillary column gas chromatography with simultaneous FID-ITD detection. The analytical run time was less than 30 min. Based on a nominal 1-1 air sample volume, the detection limit was determined as less than 0.001 μg of TDI.