Determination of optimum conditions for the analysis of volatile components in pine needles by double-shot pyrolysis-gas chromatography-mass spectrometry.

The optimum conditions for the analysis of the volatile organic components of pine needles from Pinus densiflora using double-shot pyrolysis-gas chromatography-mass spectrometry (DSP-GC-MS) were investigated with respect to thermal desorption temperature and duration of heating. A total of 41 compounds were identified using thermal desorption temperatures of 150 degrees C, 200 degrees C, 250 degrees C and 300 degrees C. Thermal decomposition products, which include acetol, acetic acid, furfurals and phenols, were observed only at thermal desorption temperatures exceeding 250 degrees C: they were not observed in the extract from a simultaneous distillation extraction (SDE) method. Heating times of 1 s, 6 s, 30 s, 150 s and 300 s were investigated at the thermal desorption temperature of 200 degrees C, whence it was found that thermal decomposition products were produced only at heating times over 30 s. The optimum pyrolyzer conditions for the analysis of pine needles using DSP-GC-MS is 200 degrees C for 6 s. Under these conditions, this method gives comparable results to the SDE method.