Heavy Metal Analysis of Blends of Methyl Esters Obtained from Four Virgin Tropical Seed Oils

This paper reports the presence of heavy metals in some prepared blends of methyl esters (biodisel) obtained from four virgin tropical seed oils. The seeds were obtained from Telferia occidentals Hook F, (TVO) and Hura crepitians L (HVO) and two edible oils; Cucumeropsis manii (CSVO) and Canarium schweinfurthii Engl (CVO). Oils were extracted, degummed and methyl esters (biodisel) prepared. The Methyl esters (ME) was then blended with petrol diesel (AGO) to form different proportions as follows; B5, B10, B20 and unblended biodiesel (B100) respectively. Heavy metal analysis was done on the unblended and blended biodiesel proportions using Perkin Elmer Instrument, Analyst 400 Atomic Absorption Spectrometer. From the results of the study, iron (Fe) was absent in all the samples except TVO-ME (8.438ppm). Lead, nickel was also absent in all samples. Traces of Cadmium was found in HVO-ME (0.064ppm). Copper was present in all the B100; TVO-ME. HVO-ME, CSVO-ME, and CVO (0.418, 0.915, 0.374 and 0.924 ppm) respectively. Zinc was present in AGO and in all the B100 except in CVO-ME. Zinc was present at various concentration (ppm) except CVO-ME. Comparatively, the levels of Zn were highest in the blends Comparing the properties of the blends i. e B5, B10, B15 and B20 to B100 and AGO. Generally the blends have less of the metals than AGO. Hence it is advisable to use blends of methyl esters/Diesel (AGO).