| The sensitive cathodic voltammetric peaks of Cr(VI), Cd2+, Cu24, Pb2+ and Ni2+ occured in EtOH-NH4Ac medium due to the adsorption of their complexes on mercury electrode. The second derivative peak heights linearly responded to their concentrations respectively. It provided a dependable and sensitive method for simultaneous determination of those metals in industrial waste water, surface water and daily used water.The electrochemiluminescence (ECL) behavior of luminol in neutral medium was studied in this paper. By the pre-treatment for platinum electrode and the enhancement of I", the quality ECL signal of luminol was obtained in the 2.0 10-8mol/L KI - phosphoric acid buffer (KH2PO4-NaOH,PH=6.70) that was excited by the positive rectangular pulse with the amplitude of 0.75V(vs. Ag). The linear concentration range of luminol relative to the cubicrote of luminous intensity is from8 10-8-3.2 10-6mol/L , with the detection limit for 8.0 10-9mol/L.Based on the studies of electrochemiluminescence of luminol in neutral medium,five kinds of the flavonoids could be sensitively determined due to their reduction effect for ECL. The ECL luminous linearly responded to the concentrations of the flavonoids. And the mechanism of reduction effect of flavonoids for luminol's effect is discussed in this paper. |
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