2.3. Sampling and analysis
Samples were taken at 10 min time intervals and
analyzed by TLC (eluent chloroform/petroleum ether,
1:3 ratio) to check the conversion to biodiesel. TLC was
chosen as a rapid analytical method and it gives quite
accurate indication of oil and biodiesel content in the
mixture After purification the biodiesel was analyzed
using a Shimadzu GC-MS Model QP-2010, equipped
with a DB-5 capillary column (0.53 mm· 30 m) J&W
Scientific.
The chemical composition of the vegetable oil was
determined on the basis of GC-MS analysis of the methyl
esters. The mean molecular weight of the esters
mixtures was calculated averaging the individual
molecular weights of each constituent ester. For methyl
esters the mean molecular weight was 293.65. The mean
molecular weight of the oil was calculated averaging the
individual molecular weights of each constituent triglyceride,
according to the fatty esters analysis (Table 1).
The average molecular weight of the oil was 878.23.