4.8. Determination of Volatile Organic Compounds (VOCs) Using Gas Chromatography-Mass Spectroscopy (GC/MS)

A methanolic extract of Streptomyces sp. strain DBT34 was used to identify VOCs using GC-MS. The GC-MS (Clarus 680) column was packed with Elite 5MS and had a size of 30 m × 0.25 mm ID × 250 μmdf. The compounds present in the extract were separated using Helium gas as a carrier at a constant flow of 1 mL/min. The instrument temperature was 260 °C when 1 μL of extract sample was injected. The oven temperature was set as follows: 60 °C (2 min), followed by 300 °C, increasing at a rate of 10 °C min⁻¹. Samples were exposed to 300 °C for 6 min. The mass detector conditions were as follows: 240 °C for transfer line and ion source temperature, and the ionization mode electron impact was set at 70 eV, with a scan time and interval of 0.2 s and 0.1 s, respectively. Obtained spectra were compared with a local copy of the NIST (2008) library database.