scholarly journals Spectrophotometric determination of the thermodynamic pK value of picric acid in water at 25 °C

1963 ◽  
Vol 67A (3) ◽  
pp. 241 ◽  
Author(s):  
Marion M. Davis ◽  
Maya Paabo
Keyword(s):  
Spectrophotometric Determination ◽  
Picric Acid

scholarly journals Utility of Certain π-Acceptors for the Spectrophotometric Determination of Hydralazine Hydrochloride

2003 ◽  
Vol 71 (3) ◽  
pp. 179-194
Author(s):  
W. El-Hawary ◽  
A. Shoukry ◽  
A. Talat
Keyword(s):  
Spectrophotometric Determination ◽  
Good Accuracy ◽  
Picric Acid ◽  
Pharmaceutical Preparations ◽  
Detection Limits ◽  
Several Variables ◽  
Accuracy And Precision ◽  
Hydralazine Hydrochloride ◽  
Ml Detection

The interaction of hydralazine hydrochloride with picric acid (I), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) (II), 2,4-dinitrobenzoic acid (III), bromanil (IV) and chloranil (V) was found to be useful for its spectrophotometric determination. The determination was carried out at 520, 510, 550, 540 and 535 nm for the reaction with (I), (II), (III), (IV) and (V), respectively. The effect of several variables on the colouring process was studied. The proposed methods have been applied successfully for the determination of hydralazine hydrochloride in pure samples and in pharmaceutical preparations with good accuracy and precision. The results were compared to those obtained by the official and pharmacopoeia1 methods. The linear ranges for obedience of Beer's law are up to 118, 54,639, 27.5 and 78.6 mg/l, Ringbom ranges are 13-100, 7.6-44.7, 77.4-445.0, 5.8-25.8 and 22.5-63.1 μg/ml, Detection limits are 4.8, 2.2, 18.4, 1.2 and 5.9 mg/l, and RSD 0.042, 0.037, 0.043, 0.013 and 0.073 for reactions of hydralazine hydrochloride with I, II, III, IV and V, respectively.

Extractive-spectrophotometric determination of some phenothiazines with dipicrylamine and picric acid

2002 ◽  
Vol 27 (1-2) ◽  
pp. 335-340 ◽  
Author(s):  
Ewa Regulska ◽  
Mikołaj Tarasiewicz ◽  
Helena Puzanowska-Tarasiewicz
Keyword(s):  
Spectrophotometric Determination ◽  
Picric Acid
Sign in / Sign up

Export Citation Format

Share Document