We have developed a high-performance liquid chromatographic method to determine aliphatic, polyfunctional amines at low levels in water, ammonia and other amines. This method is potentially valuable for determining trace &mine by-products in industrial samples, such as crude and refined piperazines. It is superior to gas chromatography which is piagued by tailing, poor reproducibility and low amine volatility_ The lack of a general or specific liquid chromatographic detector for aliphatic amines was circumvented by preparing m-toIuoy1 derivatives measurable with available ultraviolet detectors. These derivatives have desirable solubility characteristics which facilitate isolation by extraction.
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INTRODUCDON
Aliphatic polyfunctional amines are valuable chemicals in many areas of industry and medicine. For example, two of the compounds studied, putrescine (l&diaminobutane) and cadaverine (1,5_diaminopentane), are present at elevated concentrations in the urine of cancer patients'. Other compounds, L,2-diaminoethane, l&i-diaminohexarie, monoethanolamine and piperazine, are used extensively in agricultural chemicals, polyamide resins (Nylon), ethyleneurea resins, chelating agents, additives for lubricating oils, rubber chemicals2 and many other areas. As a result, measurement of these compounds at low levels in process streams, urine, end-use products and wastes is important.
Polyfunctional amines have been difFicult to impossible to measure by gas chromatography when water, ammonia and/or amine residues are present. Typically polyfunctional amines have low volatility and exhibit tailing and poor quantitative recoveries, because they are so reactive. These characteristics are particularh~ undesirable when it is important to measure low concentrations of amines in the presence of high concentrations of other amines or water.
High-performance liquid chromatography (HPLC) can overcome these disadvantages of gas chromatography. With HPLC volatility is not a factor. it is obvious