The increasing use of gallium arsenide (GaAs) in the electronics industry has produced the need for pharmacokinetic and toxicologic data on GaAs. The disposition in male Syrian golden hamsters (n = 4) following intratracheal instillation of GaAs (mean volume diameter 5.8 micron), arsenic (III) oxide (arsenite), and arsenic (V) oxide (arsenate) at a dose of 5 mg/kg body weight was examined. Blood, kidney, liver, and lung samples were collected at 1, 2, and 4 days after administration. Excreta were collected daily. Urinary metabolite profiles were determined after separation on a mixed anion-cation-exchange column. Total As content was analyzed by direct hydride flame atomic absorption spectrophotometry after digestion. Arsenic blood levels after GaAs, arsenite, and arsenate administration were 0.185 +/- 0.041, 0.596 +/- 0.117, and 0.310 +/- 0.045 ppm, respectively, after Day 1. Arsenic blood levels after GaAs administration increased to 0.279 +/- 0.021 ppm on Day 2 indicating continued absorption while levels decreased for the arsenite and arsenate groups. At Day 1 the liver contained 0.565 +/- 0.036, 2.62 +/- 0.26, and 0.579 +/- 0.144% of the arsenic dose of GaAs, arsenite, and arsenate, respectively. The arsenite and arsenate were rapidly excreted in the urine with almost half the dose appearing after 4 days; in contrast, only about 5% of the GaAs was found at the corresponding time. Total recoveries, as arsenic equivalents, for the three compounds were between 75 and 80%. Ratios of the two major urinary metabolites (dimethylarsinic acid/total inorganic As species) were 1.41, 1.71, and 0.983 for GaAs, arsenite, and arsenate, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)