DIRECT ANALYSIS OF FREE AMINES IN SALT-SOLUTIONS AT SUB-PPM LEVELS BY GAS-LIQUID-CHROMATOGRAPHY

A method was described for trace analysis of amines in salt solutions after an alkali treatment followed by direct sample injection. Different parameters that may influence the analysis were investigated, including sample handling and storing, injector temperature, injector impregnation, pH of the solution, type of salt matrix and detector response where concentration or sample volume was varied. The determination limit was of the order of 10 ppb for most amines where the decrease in sensitivity for high-boiling amines caused by increased peak broadening can be compensated for by the use of large sample volumes (up to 25 .mu.l). The average precision was 2% at an amine concentration of 4 ppm, which is roughly the same as when the amines occur in pure water or in an organic solvent. The method is now routinely used for analysis of amines in samples obtained from workplace atmosphere measurements, where the amines are usually collected in a dilute acidified aqueous absorbing solution. [There is new evidence for health hazards consequent on exposure to low levels of these compounds.].