A comparison of trace metal profiles of neem biodiesel and commercial biofuels using high performance ICP-MS

This study explores the use of high performance ICP-MS to characterize neem biodiesel and commercial biofuels in terms of their trace elemental profiles. A detailed study of this nature delineating heavy metal trends could make a useful contribution to biofuels research. Trace metals in biofuels can create unwanted problems in machinery and engines and therefore, there is a need for consummate quantitative assessment of such species. Biodiesel is known to be a valuable alternative energy resource and can be employed in existing vehicular engines without the need for serious changes in contemporary machinery. However, it has been reported that certain biofuels tend to corrode rubber hosing and tubes in vehicles, and leave unwanted deposits that could ultimately clog fuel lines. Also, trace metal emissions from use of biodiesel could lead to air pollution. Therefore, the presence of trace metals in biofuels can be detrimental both to the environment and equipment. The neem biodiesel that we investigated was produced in our laboratory from neem feedstock (kernels and fruit). A two-step acid-base catalyzed esterification process was applied to produce the neem biodiesel. Small quantities of the sample were digested in mild acid media and submitted to high resolution ICP-MS analysis. The basic physical properties of neem biodiesel were in agreement with those of regular petrodiesel (2D). Forty elements were detected in the neem biofuel and their levels were compared with those of commercially obtained biofuels (B100C/B100R) treated and analyzed under identical conditions. In general the neem biodiesel displayed a higher level of purity. The study is of definite interest to environmentalists and ongoing sustainable development. (C) 2012 Elsevier Ltd. All rights reserved.