Thermogravimetric analysis (TGA)
The previously reported method was used to determine the thermal
stability of oil (Mokbli et al., 2018) with a Model Q50 TGA (TA
instruments, New Castle, DE, USA). Oil samples (about 9 mg) were weighed
in platinum sample pans, which were loaded by an autosampler. Samples
were heated at the rate of 10 °C/min up to 600 °C under air at the flow
rate of 60 ml/min. TA Universal V4.5A software was used to analyze data.
Samples were analyzed in triplicate. The thermal stability was
determined by the onset temperature of oil decomposition following the
previous method (Kalam et al., 2017).