The contents of biodiesel in the samples were analyzed by the
gas chromatograph (Ouhua GC 9160) equipped with a DB-5Ht capillary
column (15 m 0.25 mm 0.25 mm) and a flame ionization
detector (FID). Nitrogen was used as the carrier gas and the injector
and detector temperature were both 360 C. In this work, the yield
of biodiesel was calculated based on the biodiesel collected in the
product vessel as follows