Apparatus and method for measuring acidity

An acidity measuring apparatus, comprising:

• a measuring container, wherein the measuring container contains an electrolyte solution including one of a 1,2-benzoquinone derivative and a 1,4-benzoquinone derivative both having side chains on the benzene ring, an organic solvent, an electrolyte and an acid-containing subject for measurement;
• a working electrode, a counter electrode and a reference electrode section provided in the measuring container and immersed in the electrolyte solution;
• and
• a control section for sweeping a potential of the working electrode within a prescribed range and for detecting a value of a pre-peak current generated by the acid and flowing between the working electrode and the counter electrode,
• wherein the organic solvent is an ethanol-isooctane mixture solvent containing isooctane in the range of 35% to 70%.

An acidity measuring apparatus, comprising:

• a measuring container, wherein the measuring container contains an electrolyte solution including one of a 1,2-benzoquinone derivative and a 1,4-benzoquinone derivative both having side chains on the benzene ring, an organic solvent, an electrolyte and an acid-containing subject for measurement;
• a working electrode, a counter electrode and a reference electrode section provided in the measuring container and immersed in the electrolyte solution;
• and
• a control section for sweeping a potential of the working electrode within a prescribed range and for detecting a value of a pre-peak current generated by the acid and flowing between the working electrode and the counter electrode,
• wherein the organic solvent is a mixture solvent is containing ethanol, water and isopropylalcohol.

A method for measuring an acidity of an acid-containing subject, comprising the steps of:

• performing voltammetry of the electrolyte solution including the acid-containing subject for measurement;
• and
• performing a measurement to determine the value of a pre-peak current flowing in the electrolyte solution which appears at a potential which is positive with respect to a potential at which a peak of reduction of oxygen dissolved in the electrolyte solution,
• wherein the electrolyte solution includes one of a 1,2-benzoquinone derivative and a 1,4-benzoquinone derivative both having side chains on the benzene ring, where the 1,2-benzoquinone derivative is 3,5-di-tert-butyl-1,2-benzoquinone and the 1,4-benzoquinone derivative is 2,6-dimethyl-1,4-benzoquinone.

An acidity measuring apparatus, comprising:

• a measuring container, wherein the measuring container contains an electrolyte solution including one of a 1,2-benzoquinone derivative and a 1,4-benzoquinone derivative both having side chains on the benzene ring, an organic solvent, an electrolyte and an acid-containing subject for measurement;
• a working electrode, a counter electrode and a reference electrode section provided in the measuring container and immersed in the electrolyte solution;
• and
• a control section for sweeping a potential of the working electrode within a prescribed range and for detecting a value of a pre-peak current generated by the acid and flowing between the working electrode and the counter electrode,
• wherein the pre-peak current value has a positive potential with respect to a potential position at which appears the reduction current of oxygen dissolved in the electrolyte solution, and the 1,2-benzoquinone derivative is 3,5-di-tert-butyl-1,2-benzoquinone and the 1,4-benzoquinone derivative is 2,6-dimethyl-1,4-benzoquinone.