Determination of occupational exposure to fabric brightener chemicals by HPLC

Paired-ion reversed-phase liquid chromatography was applied to the problem of determining the exposure of chemical workers to aerosols of chemical intermediates in the production of fabric brighteners, specifically: 4,4'-diaminostilbene-2,2'-disulfonic acid, disodium salt (DAS), 4,4'-dinitrostilbene-2,2'-disulfonic acid, disodium salt (DNS), and paranitrotoluene sulfonic acid, sodium salt (PNTSA), which are all light-sensitive ionic compounds. Personal samples were collected on Teflon-coated glass fiber filters through which air was drawn at 1.7 Lpm. DAS, DNS and PNTSA were desorbed quantitatively in water from the filters. Tetrabutylammonium phosphate served as the ion-pairing reagent to these anions and was added to the eluent solutions. The samples were separated on an octadecylsilyl column with a methanol/water gradient. These three compounds eluted with good separation in 15 min. Monitoring absorbance of light at 254 nm, one can easily obtain detection limits of 2 micrograms/mL or less. Air concentrations of 0.02 mg/m3 were measured readily by personal sampling. Airborne exposures in this facility were found to range from nondetectable levels up to 60 micrograms/m3 DAS. A fixed high volume sampler collected between 0.2 and 2 micrograms/m3 each of DAS, DNS and PNTSA. The enclosure of the reactors and transport of materials in solution or as a slurry minimize exposure.