Flow-injection determination of Novalgin using amperometric detection at a glassy carbon electrode.

An electroanalytical study of the oxidation of Novalgin (dipyrone) at a glassy carbon electrode in aqueous solution has been carried out. A flow-injection method with amperometric detection based on this oxidation process is also described. The influence of flow rate, coil length and injection volume on the sensitivity of the method was established. The calibration graph was linear within the range 3 x 10(-6)-3 x 10(-5) M in an ammonia buffer solution (pH 9) as a potential of 0.4 V versus an Ag/AgCl reference electrode. The sampling rate was 54 samples h-1. The applicability of the method to the determination of Novalgin in pharmaceutical preparations was demonstrated by investigating the effect of potential sources of interference and by analysing commercial preparations.