Author(s): Hicham Boughendjioua and Zahra Boughendjioua

Abstract: Three main tools are used to determine the structures of organic molecules. These tools are infrared (IR) spectroscopy, mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Infrared Spectroscopy (IR), Mass Spectrometry (MS) and Nuclear Magnetic Resonance Spectroscopy (NMR). Organic molecules absorb light (infrared, ultraviolet, etc.) at particular wavelengths based on different vibrational modes unique to the specific functional groups and structural features. In the present study, the volatile compounds of Rosemary (Rosmarinus officinalis L.) collected from Azzaba, Skikda city (Algeria), were detected and identified by Fourier Transformed Infrared Spectroscopy (FTIR) analysis. FTIR allowed us to identify 10 volatile compounds and indicated thanthe functional groups of the essential oils are Aromatic C=C Bending, C-H (Aromatic) and Carboxylic Acid O-H Stretch (broad, v). The obtained results have shown that the essential oil can be fully utilized for pharmacy, cosmetology and industry.