GC–MS system allows the chromatographic analysis of this volatile
fraction without matrix interferences.Although SPME has been
widely used for the fractionation/preconcentration of food vola-
tiles prior to their chromatographic analysis it has scarcely
been applied to the study of blackberry aroma
Despite the above mentioned advantages of SPME,thechange-
able precision when multicomponent mixtures are to be analyzed
has frequently questioned the quantitative performance of SPME
particularly for studies on characterization of samples where preci-
sion is the most important analytical parameter.Thus,few papers on
application of SPME for fractionation of food volatiles show the
dispersion of quantitative data or refer data precision for only
a very limited number of volatiles,as those included in model
systems used for optimization of SPME operating conditions
Although the matrix effect is known to play arole on volatile
recovery and Multiple Headspace SPME approaches have been used
to estimate the effect the matrix effect's influence on data
precision has not yet been considered in papers on SPME.
Previous studies carried out in ourlaboratory on fractionation
of volatiles from different food samples(honey and cumin seeds)
by means of diverse techniques such as SPME and Purge and
Trap(P&T)have shown an improvement of data precision when
considering relative data(percentage of total volatiles)rather