Method for the detection and measurement of nitric oxide, nitrogen dioxide and mixtures thereof

A method for electrochemically detecting NO including the steps of (1) feeding a gaseous sample containing said gas to the anode of an electrochemical cell comprising an anode, a reference electrode, a cathode and an aqueous electrolyte in contact with said anode, cathode and reference electrode, said anode comprising a gold catalyst bonded to a hydrophobic material to provide a diffusion electrode;

• (2) maintaining said anode at a fixed potential in excess of 1.5 up to 1.9 volts with respect to the potential of the reversible hydrogen couple in the electrolyte of said cell;
• and (3) measuring the current flowing between said anode and cathode of said cell to quantitatively determine the amount of NO in said gaseous sample.

A method for electrochemically detecting NO in a gaseous sample containing both NO and NO.sub.2 including the steps of (1) contacting said gaseous sample containing said gases with filter means for the removel of NO.sub.2 ;

• (2) feeding the resulting gaseous sample to the anode of an electrochemical cell comprising an anode, a reference electrode, a cathode and an aqueous electrolyte in contact with said anode, cathode and reference electrode, said anode comprising a gold catalyst bonded to a hydrophobic material to provide a diffusion electrode;
• (3) maintaining said anode at a fixed potential in excess of 1.5 up to 1.9 volts with respect to the potential of the reversible hydrogen couple in the electrolyte of said cell;
• and (4) measuring the current flowing between said anode and cathode of said cell to quantitatively determine the amount of NO in said gaseous sample.

A method for electrochemically detecting NO.sub.2 in a gaseous sample containing both NO and NO.sub.2 including the steps of (1) contacting said gaseous sample containing said gases with filter means for the removal of NO;

• (2) feeding the resulting gaseous sample to the anode of an electrochemical cell comprising an anode, a reference electrode, a cathode and an aqueous electrolyte in contact with said anode, cathode and reference electrode, said anode comprising a gold catalyst bonded to a hydrophobic material to provide a diffusion electrode;
• (3) maintaining said anode at a fixed potential in excess of 1.5 up to 1.9 volts with respect to the potential of the reversible hydrogen couple in the electrolyte of said cell;
• and (4) measuring the current flowing between said anode and cathode of said cell to quantitatively determine the amount of NO.sub.2 in said gaseous sample.