Table I.

Effect of Foreign Species on the Determination of 0.6 μg ml⁻¹ Doxepin Hydrochloride

Sample number	Foreign species	Maximum tolerance limit (mg ml−1)
1	Glucose	0.10
2	Fructose	0.16
3	Lactose	0.30
4	Starch	0.20
5	Sodium benzoate	0.30