Air sampling and analytical procedures for benzidine, 3,3'-dichlorobenzidine and their salts.
Morales-R; Rappaport-SM; Hermes-RE
Am Ind Hyg Assoc J 1979 Nov; 40(11):970-978
A personal air sampling technique for measuring concentrations of benzidine (92875), 3,3'-dichlorobenzidine (91941), and their salts is described. A glass fiber filter is used to collect the aerosols, and a bed of silica gel is used to collect the vapors. Salts are converted to free amines before analysis, and measurement is performed using high performance liquid chromatography. Air sample temperature and humidity do not affect measurement results. Benzidine and its salts show significant loss when stored for several days before analysis at temperatures above minus 15 degrees- C, but 3,3'-dichlorobenzidine does not reveal loss when stored. The authors conclude that the new sampler is small and easy to use, will collect either physical form (aerosol or vapor) with high efficiency, and should be applicable in all situations. The analytical procedure is quick and provides separation between the test compounds and interfering substances. The authors recommend that benzidine samples be stored cold and tested within a few days to avoid loss.
NIOSH-Publication; NIOSH-Contract; Contract-IA-74-35; Chemical-analysis; Carcinogens; Sampling-devices; Air-sampling-equipment; Sampling-methods; Personal-exposure-detectors
American Industrial Hygiene Association Journal