The full evaporation technique (FET), which is a variant of headspace analysis used to overcome matrix effects, was combined with capillary gas chromatography (GC) and ion-trap detection (ITD). The aim was to enable quantitative tests of volatile organic compounds (VOCs) in blood and postmortem tissue samples. FET was applied to sample sized less than 35 mg whose VOCs were released from the matrix at an equilibration temperature of 130 degrees C. A capillary column with a nonpolar stationary phase was used for GC, and ITD was performed with the mass spectrometer run in full-scan mode. The potential of FET-GC-ITD was studied for the analysis of blood samples spiked with low concentrations of ethanol, acetone, 2-propanol, and 2-butanone and on brain tissue that contained methyl tert-butyl ether (MTBE), Benzene, toluene, ethylbenzene, o-, m-, and p-xylene, and propylbenzene. Samples were obtained from the bodies of victims who had inhaled smoke during an arson or accidental fire. There was a linear relationship between peak area and sample size, which indicates that the conditions of full evaporation were met and that the matrix effect was negated. The total analyte amount in the test sample at the limit of quantitation was in the range of 0.4-1 nmol for polar VOCs in blood and 0.03-0.1 nmol for nonpolar VOCs in brain tissue. Data on precision and accuracy of the method are reported.