Short open tubular columns to trap organic micro-pollutants from aqueous samples

In two previous articles some of the present authors had assessed and propo sed the direct use of an analytical capillary column with a bonded phase fo r both trapping and later GC analyzing organic compounds. A few factors inf luencing band dispersion of the solute had been investigated and a mathemat ical relationship developed to calculate the degree of retained-substance d ispersion starting from GC peak widths. This paper presents the effects of other variables (such as stationary-phas e polarity, percentage of methanol added to samples, class of tested compou nds, pH of some solutions and ionic strength of the aqueous medium) on the trapping efficiency A new approach is also proposed for the determination o f the constants necessary to use the above-mentioned relationship. The poss ibility of applying this sampling technique to "real"-samples analysis was assessed after evaluating the effects of a washing treatment of the station ary phase on the retained solutes. The suggested technique allows direct pr econcentration and GC determination of organic compounds that are not very soluble in water.