Patent ID: 8440068

Claim:
A method of measuring a total concentration of a plurality of specific substances in a sample solution comprising use of: a sensor, wherein said sensor comprises a measuring electrode that includes as components a mediator and an enzyme that selectively act on at least said plurality of specific substances each serving as a substrate, a counter electrode, and a voltage-current characteristic measurement section, said measuring electrode and said counter electrode being connected to said voltage-current characteristic measurement section to apply a voltage therebetween, wherein said method comprises: allowing said sensor to come into contact with said sample solution; applying a voltage between said measuring electrode and said counter electrode during measurement, which applied voltage includes a voltage that allows a variety of current values for said plurality of specific substances at a same concentration and a same applied voltage to fall within about 20% or less of a maximum of said current values at said applied voltage in an analytical curve representing a relationship between said applied voltage and said respective current value at a specific concentration for each of said plurality of specific substances; measuring a response current value generated between said measuring electrode and said counter electrode under said applied voltage; and determining a substance concentration corresponding to said applied voltage and said response current value in said analytical curve, as a total concentration of said plurality of specific substances in said sample solution.