Method for detecting L-tyrosine content in beer sample

The invention discloses a method for detecting L-tyrosine content in a beer sample. A tri-electrode system is adopted, under the room temperature, a 4,5- dichloroo-phenylenediamine nickel complex-graphene oxide-modified glassy carbon electrode is used as a working electrode, a saturated calomel electrode is used as a reference electrode and a platinum electrode is used as an auxiliary electrode respectively to carry out cyclic voltammetry sweeping in PBS (Phosphate Buffer Solution) (pH=7.0) containing L-tyrosine with different concentrations, and anodic peak current value of the L-tyrosine with different concentrations is recorded; the result indicates that the concentration of the L-tyrosine is within a range of 1.0*10 mol/L-1.0*10 mol/L, and the concentration has good linear relation with the anodic peak current value; a working curve is drawn, a regression equation is Ip(A)=0.319C(mmol/L)+0.179, a correlation coefficient is 0.995 (n=5) and detection limit is 2.3*10 mol/L (S/N=3). The L-tyrosine content can be measured by utilizing cyclic voltammetry. And the method disclosed by the invention is flexible and quick in detection.