Simple and very sensitive spectrofluorimetric methods were
developed for determination of adrenaline (I)–procaine
hydrochloride (II) mixture and salbutamol sulfate (III) –
guaifenesin (IV) mixture. Adrenaline (I) in the first mixture was
determined by coupling with 5-diazo-1,2,4-triazolo-3-carboxylic
acid (DTCA) reagent in alkaline medium forming fluorigenic
product which can be measured at 340 nm (ex. 245 nm), while
procaine hydrochloride (II) gave no fluorescence. Salbutamol
sulfate (III) was analyzed by reaction with ethyl acetoacetate
(EAA) forming coumarin derivative, which can be measured at 320
nm (ex. 280 nm). Guaifenesin (IV), the second drug in mixture has a considerable native fluorescence in methanol was measured at
310 nm (ex. 230 nm). All variables affecting reaction conditions
were optimized. Linear correlations were obtained over the range
of 19-100, 37-400 and 22-150 ng/ml for (I), (III) and (IV),
respectively. The proposed methods were successfully applied for
the analysis of the studied drugs in their pure and commercial
dosage forms and the obtained results were in good agreement with
those obtained from the reported methods; no significant difference
in the accuracy and precision as revealed by the accepted values of
t- and F-tests, respectively.