US EPA

5920472 

Journal Article 

Determination of 1,3-Dinitrobenzene and Its Metabolites in Rat Blood by Capillary Gas Chromatography with Electron-Capture Detection 

Bailey, E; Peal, JA; Philbert, M 

1988 

1 

Journal of Chromatography
ISSN: 0021-9673 

425 

1 

187-192 

English 

3360869 

10.1016/0378-4347(88)80020-3 

WOS:A1988M506000020 

In preparation for a neurotoxicity study concerning 1,3-dinitrobenzene (99650) (1,3-DNB) in conventional and germ free rats, a sensitive and specific method was developed for determining the parent compound and its metabolites in small volumes of whole rat blood. The metabolites analyzed were 3-nitroaniline (99092) (3-NA) and 3-nitroacetanilide (122281) (3-NAce). Oral doses of 1,3-DNB were given to conventional male F-344-rats and germ free male F-344-rats, and blood was sampled from 30 minutes up to 24 hours after dosing. Initial identification of 1,3-DNB, 3-NA, and 3-NAce was made by capillary gas chromatography with mass spectrometry in ethyl-acetate extracts of blood from rats dosed with 50mg/kg. Electron capture detection was used to detect the parent compound and 3-NAce with high sensitivity. However, to detect 3-NA, it was first necessary to derivatize the metabolite with an electrophoric derivatizing reagent. The fluoroacyl derivative made from heptafluorobutyric-anhydride (HFBA) was chosen for this purpose. All three nitro compounds responded effectively using ethyl-acetate as the solvent with a single extraction with two volumes of ethyl-acetate accounting for a 92 percent recovery from the blood of rats dosed with 25mg/kg 1,3-DNB. No purification of the ethyl-acetate extract was needed for analysis of the parent compound and 3-NAce in rat blood. When attempting to quantitate all three compounds at the same time, 1,3-DNB was lost when the extract was evaporated to remove excess HFBA. Mean recoveries of external standards were 99.9 percent for 1,3-DNB, 92.9 percent for 3-NAce, and 103.8 percent for 3-NA. The authors conclude that the method as presented is accurate and precise for measuring 1,3-DNB and the two major metabolites in blood.