A trinitrobenzene sulfonate (TNBS)-selective PVC membrane electrode based on the ion associate of tetradodecylammonium and TNBS as the electroactive species was prepared The electrode exhibits excellent stability and selectivity and can be used for anal. in solns. with pH 3-12. At 25癈, the electrode exhibits Nernstian response for 1 ?10-6-1 ?10-2 mol TNBS/L with a slope of -58 mV/decade. Trinitrobenzenesulfonic acid is a common reagent for amino acids; the electrode is feasible for indirect determination of amino acids. Calibration curves are linear for (0.2-2.00) ?10-3 mol L-1 for both glycine and glutamic acid.

Key words: AMINO ACID, APPLICATION, SODIUM COMPOUNDS, ION SELECTIVE ELECTRODE, POLYVINYL CHLORIDE, GLUTAMIC ACID, HIGHER ALKANE P, MEMBRANE ELECTRODES, NITROBENZENE, C12 COMPOUNDS, CHEMICAL REAGENT, BENZENESULFONIC ACID P, QUATERNARY AMMONIUM COMPOUNDS, NSFC