Assay
Transfer an accurately measured volume of Oral Solution, equivalent to about 100 mg of isoniazid, to a 100-mL beaker. Add 50 mL of a mixture of 1 part of potassium bromide in 10 parts of dilute hydrochloric acid (1 in 6), and proceed as directed under
Nitrite Titration 451, beginning with cool to 15
. Each mL of 0.1 M sodium nitrite is equivalent to 13.71 mg of isoniazid (C
6H
7N
3O).