Quantification of triglyceride content in oleaginous materials using thermogravimetry

摘要

Laboratory analytical methods for quantification of triglyceride content in oleaginous biomass samples, especially microalgae, require toxic chemicals and/or organic solvents and involve multiple steps. In this paper, a simple triglyceride quantification method that uses thermo-gravimetry is described. This method is based on the observation that triglycerides undergo near-complete volatilization/degradation over a narrow temperature interval with a derivative weight loss peak at 420 degrees C when heated in an inert atmosphere. Degradation of the other constituents of oleaginous biomass (protein and carbohydrates) is largely complete after prolonged exposure of samples at 320 degrees C. Based on these observations, the triglyceride content of oleaginous biomass was estimated by using the following two-step process. In Step 1, samples were heated to 320 degrees C and kept isothermal at this temperature for 15 min. In Step 2, samples were heated from 320 degrees C to 420 degrees C and then kept isothermal at 420 degrees C for 15 min. Our results show that mass loss in step 2 correlated well with triglyceride content estimates obtained from conventional techniques for diverse microalgae and oilseed samples.