Fisher M A, Hunt J N
Digestion. 1976;14(5-6):409-14. doi: 10.1159/000197964.
A sensitive method for measuring haemoglobin in gastric contents using the rate of change of optical density of a mixture of orthotolidine and hydrogen peroxide in the presence of haemoglobin, is described. The method can measure the blood normally lost in 10 min from the gastric mucosa.