VOLTAMMETRIC METHOD OF DETERMINING METHYLPARABEN IN EYE DROPS Russian patent published in 2024 - IPC G01N27/49 

FIELD: analytical chemistry.

SUBSTANCE: disclosed is a voltammetric method for the quantitative determination of methylparaben in eye drops, involving the use of a three-electrode electrochemical cell containing a background electrolyte, into which an indicator, auxiliary and silver chloride reference electrode is placed, a voltammogram of the background electrolyte is recorded, then successively adding aliquots of eye drops and standard additives of methylparaben solution, recording anode voltammograms of electrooxidation of methylparaben relative to silver chloride reference electrode, concentration of methylparaben is determined by height of anode peak by method of standard additives, where indicator electrode used is mechanically cleaned disc impregnated graphite electrode, as an auxiliary electrode, a silver chloride electrode is used, as a background electrolyte, the Britton–Robinson buffer solution with pH 6.02 is used, preliminary electro-accumulation is carried out for 20 s at a potential of -1.0 V, stirring for 10 s and quenching solution for 20 s, recording the anode voltammogram of the background electrolyte solution in the potential sweep range from +0.5 to +1.2 V at rate of 80 mV/s, wherein after introducing aliquots of eye drops and standard additives of methylparaben solution, electro-accumulation is carried out under said modes, and recording voltammograms of electrooxidation of methylparaben is carried out at potential 0.87±0.05 V in the mode of the first derivative.

EFFECT: invention provides developing a voltammetric method for quantitative determination of methylparaben in eye drops by anodic voltammetry.

1 cl, 4 dwg, 1 tbl, 1 ex