Quantitative analysis of biosurfactants using Fourier Transform Infrared (FT-IR) spectroscopy

A quick and simple technique has been developed that is suitable to quantif y the concentration of most types of biosurfactants in a typical growth med ium using infrared spectroscopy. The area of the peak due to the carbonyl b ond of the biosurfactant was measured and compared to the area of the nitri le peak in an internal standard (anthracenecarbonitrile). This ratio showed a linear trend with the concentration of biosurfactant in the medium for c oncentrations from 0.2 to 3.2 g biosurfactant l(-1). The presence of hydroc arbons in the media and variations in the pH of the media did not interfere with the measurements.