Fluorimetric determination of procaine in pharmaceutical preparations based on its reaction with fluorescamine

A simple spectrofluorimetric analysis of a local anaesthetic named procaine using a specific labelling reagent for primary amino groups, has been developed. Because procaine shows very weak native fluorescence, the technique of spectrofluorimetry has been very much limited for its determination. A detail study of the variables affecting the derivatisation reaction (pH, fluorescamine (FC) concentration, temperature, reaction time), have minuciously been studied. The minimum detectable quantity is estimated as 7.7 ng ml(-1), with a relative standard deviation of 2.16% (ten determinations) for a procaine concentration of 100 ng ml(-1). The present method can be employed for the analysis of procaine by direct fluorescence measurements, without the interference from other compounds. The applicability of the present methodology have been demonstrated analysing three pharmaceutical preparations containing the analyte with satisfactory results.