Abstract
A method for collecting, storing and quantifying airborne vapors of O-phenylenediamine (OPD) in the workplace has been developed. The vapors are collected on 100 mg of Tenax-GC packed in 4 mm ID glass tubing wrapped with aluminum foil. The OPD is desorbed and derivatized using a 10% solution of acetic anhydride in acetonitrile to form diacetamidobenzene (DAAB). The DAAB was subsequently quantified by injecting 10 µL of the solution into a liquid chromatograph equipped with a UV-detector (254 nm), a Partisil PXS PAC column and a 7% methanol in 1-chlorobutane mobile phase. The limit of detection is approximately 10 ng. Samples collected from test atmospheres containing OPD in dry air at concentrations ranging from 0.05 to 0.2 mg/m3 gave an overall recovery of 86.6%. Recoveries of samples collected from atmospheres humidified to 80% relative humidity were 79%. The capacity of the tube is at least 25 µg which is sufficient for either short or long term samples.