Toxicology of Industrial Compounds

82 METHODS FOR THE DETERMINATION OF REACTIVE COMPOUNDS
Figure 6.5 HPLC/ECD profiles obtained after hydrolysis and extraction of
haemoglobin samples isolated from an untreated rat (control) and from rats treated
for 4 weeks with DCB (2 mg kg −1 ), Direct Red 46 (160 mg kg −1 ), Pigment Yellow
13 (400 mg kg −1 ) and Pigment Yellow 17 (400 mg kg −l ) as well as of commercially
available bovine haemoglobin (Hb-bovine).
life span of the erythrocyte. Haemoglobin adduct formation, therefore, was
used to monitor the liberation of DCB from diarylide pigments.
Rats were treated by daily oral gavage for 4 weeks with the pigment at
daily dose levels of 400 mg kg −1 body weight. As a positive control,
animals were treated accordingly with DCB (2 mg kg −1 ) or with Direct Red
46 (160 mg kg −1 ), asoluble azo dye with known bioavailability of DCB.
After termination of the treatment, haemoglobin was isolated and
hydrolysed in 0.1 N sodium hydroxide. The liberated DCB and
monoacetyl-DCB were extracted with toluene/2-propanol and analysed by
HPLC with electrochemical detection. With 2 mg DCB kg −1 body weight
DCB and monoacetyl-DCB adducts were clearly detectable, amounting up