Analyses with injection of 1 μL of hexanic solutions of essential oils were made in the split mode (1:20) in the same chromatographic conditions used in the HS-SPME/GC-MS analysis. Linear temperature programmed retention indexes (RI) were calculated using the retention data of linear alkanes (C9–C22), along with retention data of the substances of the essential oils. The identification

of the volatile components was based on comparison of their mass spectra with those of NIST 2.0 and Saturn Libraries and those described by Adams (1995), as well as by comparison of their retention indexes with literature data. Statistical analysis was performed using the MINITAB 14 for Windows statistical software to characterise and describe the homogeneity among

oils samples of two stages of maturation. Cluster’s statistical analysis with Average BLU9931 Linkage and Euclidean Distance was applied in the normalised percentage value of the substances. The similarity index was calculated as similarityab = (1 − dab/dmax) × 100, where dab is the Euclidean distance of samples a and b, and dmax is the largest Euclidean distance in the data set. The analytical parameters adopted for the analysis of fruits and leaves were 45 min (extraction time), 40 °C (extraction temperature), 60 s (desorption time) and 50 mg of leaves and 100 mg of fruit as mass of sample. Samples were placed in vial of 4 mL. Table 1 shows a total of 100 compounds

check details detected Protein kinase N1 in fruits and leaves by both techniques. Qualitative and quantitative differences found in volatile compounds isolated with HS-SPME and conventional methods such as HD and LLE are reported in the literature. Some articles presents the HS-SPME extracting the highest number of compounds (Bicchi et al., 2008 and Vichi et al., 2007) while others attribute a better performance to the conventional techniques (Paolini, Leandri, Desjobert, Barboni, & Costa, 2008). The two techniques have different principles of extraction, the HD is a method of exhaustive extraction while SPME is based in equilibrium. In the SPME extraction the molecules of the analyte have to move from the matrix and penetrate the coating fibre. For this reason, resistance to mass transfer must be overcome, until it strikes a partition balance or adsorption of the analyte between the fibre and the environmental that it surrounds. Therefore, the theory of SPME is based on the kinetics of mass transfer between phases and in the thermodynamics that describes the partition equilibrium of the analyte between them (Valente & Augusto, 2000). Moreover, the fibre coatings present different chemical affinities for different analytes, as presented in the Fig. 1, and whatever the coating is, it will require a calibration with standards in a quantitative analysis.