Search

WOS: 000207179200012, PubMed ID: 15841263, The essential oil of Betula pendula Roth. buds was obtained using both hydrodistillation and microdistillation techniques and their chemical compositions were analyzed using both gas chromatography ( GC) and gas chromatography-mass spectrometry (GC-MS). Overall, more than 50 compounds were identified representing 80% and 92% for hydrodistillation and microdistillation, respectively. The main components ( by hydrodistillation and microdistillation, respectively) found were alpha-copaene (12% and 10%), germacrene D (11% and 18%) and delta-cadinene (11% and 15%) in the analyzed essential oils. The microdistillation technique proved to be a useful tool and compliant alternative when compared to hydrodistillation.

Nine European laboratories have taken part in a joint exercise in which two samples, one containing about 98% benzene and the other 90% toluene, were analysed, using chromatographic equipment available to each laboratory. For each sample, a known quantity of a specified internal standard was used and the composition of the samples was calculated from calibration data based on (I) peak height, (2) peak height X retention distance, (3) peak height x width of peak at half peak height. The precision of the results is least for method (3), but method (I) is preferred because it is the simpliest. The results for the toluene sample were less precise than those for the benzene sample. Further work is in progress.