A new method for the rapid determination of volatile substances: the SPME-direct method - Part I: Apparatus and working conditions

A new method for the measurement of volatile substances constituting the od ors of food or other material is presented. The apparatus developed consist s of a standard injector, as used for gaschromatography, linked directly to a detector without a separating column. The headspace is produced in a via l and sampled by a solid phase micro extraction (SPME) fiber. The volatile substances on the SPME are desorbed directly into the detector and the sign al is quantified. The detectors tested are the dame ionisation detector (FI D) and the nitrogen phosphorus detector (NPD). Other detectors can also be adapted. The signal obtained consists of a single peak, which is directly p roportional to the concentration of the headspace volatiles. The reproducib ility of the measurement for standard mixtures, as measured by their variat ion coefficient, is about 2.4%. (C) 2001 Elsevier Science B.V. All rights r eserved.