Abstract: A method for determining nitrogen oxides in gaseous or liquid samples is disclosed. A semi-permeable membrane- type sensor comprising a sensor electrode, reference electrode and an electrolyte having a pH range of 6.8-8.0 or 8.0-9.2 is used. Potential between the electrodes is monitored as a measure of nitrogen oxides in the sample. When an electrolyte having a pH range of 8.0-9.2 is used the electrolyte additionally contains at least 25% v/v of a water miscible solvent having a dielectric constant of at least 10.

Abstract: A method is disclosed for determining carbon dioxide content in gaseous or liquid samples. A semi-permeable membrane-type sensor comprising a sensor electrode, reference electrode and an electrolyte having a pH range of 9.5-11.0 or 10.7-12.0 is used. Potential between the electrodes is monitored as a measure of carbon dioxide in the sample. When an electrolyte having a pH range of 10.7-12.0 is used the electrolyte additionally contains at least 255 v/v of a water miscible solvent having dielectric constant of a least 10.

Abstract: A method of determining ammonia in a gaseous or liquid sample is disclosed. A sensor comprising a sensing electrode, a reference electrode, a semi-permeable membrane and an electrolyte is used. The electrolyte is buffered to a pH value between 4.5 and 6.5 and is initially free of any salt capable of dissociating to form therein ammonium ion. The electrolyte may optionally contain at least 25% v/v of a water miscible solvent having a dielectric constant of at least 10. In the latter case the pH of the electrolyte is between 5.5 and 7.5. The potential between the sensing electrode and reference electrode is monitored as a measure of ammonia in the sample.

Abstract: Gas detection electrochemical cell featuring, in one aspect, a liquid electrolyte free of any salt capable of dissociating to form in said electrolyte a weak acid or weak base (other than H.sub.3 O.sup.+ or OH.sup.-) which forms upon dissociation of the gas being measured.

Abstract: A method of detecting hydrogen cyanide using an electrochemical cell is disclosed. The cell comprises an electrolyte which is initially free of any salt capable of dissociating to form cyanide ions, a pH detection electrode and a reference electrode. A membrane permeable to hydrogen cyanide gas is used and the potential developed between the electrode is monitored as a measure of hydrogen gas partial pressure.

Abstract: Gas detection electrochemical cell featuring, in one aspect, a liquid electrolyte free of any salt capable of dissociating to form in said electrolyte a weak acid or weak base (other than H.sub.3 O.sup.+ or OH.sup.-) which forms upon dissociation of the gas being measured.

Abstract: Electrochemical cell including an ion-specific membrane containing, in one aspect, Ag, S, and Sb and in another aspect a ternary compound of Ag, S and one of As, Sb, Se and Te. Methods are disclosed for making ternary compounds of Ag, S and one of Se, Sb, Te and As.