[Improvement of the concentration method of the "head space" above wine for direct gas chromatographic analysis by means of two absorbent polymers (author's transl)].

It has been defined, in a previous work, a procedure for the "head space" gas chromatographic analysis. This method allowed the separation of 17 volatile constituents, utilizing Porapak Q, either as trap or chromatographic adsorbent. A series of new experiences have improved this precedure, adopting as trap two polymers (Porapak Q, copolymer of the ethyl-vinyl-benzene divinyl-benzene; Tenax GC porous polymer 2,6-diphenyl-p-phenilene oxide) and two different chromatographic phases. Furthermore, it has been entirely modified the introduction of the sample into the gas chromatographic column simplifying the handling and improving the operative conditions (times and temperature of desorption). The analysis of the "head space" carried out on wines of different aromatic compositions (Riesling) and on wines at different degree of ageing (Rubesco), besides having allowed the separation of 61 volatile components, 27 of which have identified, has put in evidence the sensitivity of this procedure.