Agilent 6890n gc ms

BBST and BOST were prepared with modification according to the previous procedure.³¹ 2,5-Dimercapto-1,3,4-thiadiazole (40 mmol) and NaOH (80 mmol) were mixed and stirred in 50 mL ethanol (purity ≥99.5%) at 80 °C until the mixture became a colorless solution. The organic halides (80 mmol) were added and stirred constantly. After the reaction had finished, the mixture was extracted twice using ethyl acetate and water. The resulting solvent layer was then collected and subjected to drying using magnesium sulfate. The next step was to concentrate the solution using a rotavap evaporator, which yielded the desired products. The synthetic pathway for the additives is shown in Scheme 1.
The chemical structure of the synthesized dimercaptobenzothiadiazole additives was confirmed by nuclear magnetic resonance (Brüker Avance III, 600 MHz), Agilent 6560 iFunnel Q-TOF LC-MS, and Agilent 6890N GC-MS. The spectra data were provided in ESI data Fig. S1 and S2.†

Thyme and oregano essential oils have been chosen because they are rich in bactericidal and anti-fungal monoterpene derivatives such as carvacrol and thymol (low molecular weight volatile components [19 (link)]). Due to these properties, the essential oils are used in preparations against skin infections, in the treatment of fungal infections of the nails, in dental medicine, in cosmetics, various medicines and, of course, in food preparations [29 (link)].
The chemical composition of the essential oils consists of a mixture of compounds, in different percentages, which together give the specific bioactive properties. Thyme and oregano essential oils used were analysed with Agilent 6890 N GC-MS highlighting the main constituent compounds: carvacrol 57.4%, ɑ-terpinene 32.4%, o-cymol 3.9%, for thyme essential oil [30 (link)] and thymol 64.4%, carvacrol 27.6%, limonene 3%, for oregano essential oil [31 ]. These compounds compositions are in agreement with those found in literature [32 (link)].