An in-line analytical measurement method for the determination of methanol and water in biodiesel was studied. Different novel selective methods such as gas chromatography ( GC)-ASTM method, high performance liquid chromatography (HPLC) for both contaminant and Fourier transform infrared (FT-IR) spectroscopy for methyl ester (FAME) content were used. The segmented flow apparatus was built in-house from 0.22 inch diameter clear polypropylene tubing, which allowed for visual monitoring of the liquid and helium gas mixing. The helium carrier gas flow was controlled through the gas chromatography (GC) injection port. Each biodiesel standard was pumped at 0.4 mL/minute into the flow analysis apparatus starting with the lowest concentration. The results showed that the response time for the prototypes was greater than 30 seconds and could be reduced to as little as a few seconds with optimization of the tube lengths.
- Mass spectrometry