Direct spectrophotometric determination of thebaine in Arya II population capsules of Papaver bracteatum Lindl.

A simple spectrophotometric determination of thebaine based on the complexation reaction with bromcresol green was developed. The yellow complex was extracted with chloroform over the pH 1.5--4.

Spectrophotometric determination of diphenhydramine. HC1 in pharmaceutical preparations.

A new spectrophotometric method has been developed for determining diphenhydramine. HC1, based on solvent extraction into chloroform of the complex formed with bromocresol green. The complex solution in chloroform showed maximum absorption at 415 nm and obeyed Beer's law over the concentration range of 3.

Rapid spectrophotometric determination of ascorbic acid in citrus fruits.

A new spectrophotometric method has been developed for determining ascorbic acid in citrus fruits. The method is based on interaction between dimethoxydiquinone and ascorbic acid, followed by extraction with chloroform. The resulting chloroform solution gives a maximum absorption at 530 nm, a determination limit of 22.

Spectrophotometric determination of diphenhydramine hydrochloride using dipicrylamine.

A spectrophotometric procedure for the determination of diphenhydramine hydrochloride based on the reaction with dipicrylamine was developed. A yellow complex forms and is easily extractable by chloroform at pH 5. The mole ratio of diphenydramine hydrochloride to dipicrylamine in the complex is 1:3.