FIELD: analytical chemistry.
SUBSTANCE: method for determining methionine in model aqueous solutions by cyclic voltammetry on a graphite electrode modified with palladium colloidal particles includes modifying the graphite electrode with palladium colloidal particles from a palladium sol for 60 s at an accumulation potential of -1.0 V, followed by registration of cathode maxima at a rate of potential change 100 mV/s against the background of 0.1 M NaCl solution in the potential range from -0.8 to 1.0 V. The concentration of methionine is determined by the value of the cathode maxima of the current-voltage curve in the potential range from minus 0.30 to minus 0.60 V relative to a saturated silver chloride electrode by the method of qualified mixture additions.
EFFECT: extension of the range of determined concentrations from 1⋅10-12 to 1⋅10-10 mol/l and reducing the time of analysis by 5 times.
1 cl, 1 tbl, 3 dwg
