The manometric estimation of nitrite in solution and in tissue.

Amidosulphonic acid. SO2 was bubbled through a saturated solution of hydroxylamine hydrochloride [Raschig, 1887] for 48 hr. at room temperature and the mixture kept at 100 for,a further 3-4 days. The crystals of NH2SO3H were recrystallized from H20 (500 -+ -100).. Sodium nitrite. A.R. NaNO2 was twice recrystallized and analysed volumetrically by the method of Adie & Wood [1900] as modified by Cool & Yoe [1933]. The solid contained 99*5 + 0.1 % NaNO2; stock solutions were stable indefinitely. Other chemicals were of A.R. quality and contained no nitrite. Recalibrated pipettes were used for the delivery of NaNO2 solutions. Tissue. Pork muscle (loin), after rigor, was used; different samples showed no difference in behaviour. The mean water content was 76 g. H20/100 g. tissue.