Ion-selective electrodes in organic analysis: determination of amines via in situ generation of dithiocarbamates

After derivatisation to the corresponding dithiocarbamates by treating with aqueous sodium hydroxide and carbon disulphide in a two-phase reaction, primary and secondary aliphatic amines were determined by the use of a tetraheptylammonium diethyldithiocarbamate poly(vinyl chloride) matrix membrane electrode. This membrane electrode exhibited Nernstian response to amine concentrations down to 4.0 × 10-4 M and had an average Nernstian slope of 50.7 mV per concentration decade over three determinations (standard deviation = 1.01 mV). Common inorganic and organic ionic species did not interfere with the amine determinations.