Fig. 8
Chromatogram of the supernatant from a Clostridium acetobutylicum ABE fermentation after 23 h analyzed with the 50 mm guard column showing ethanol (peak 1), n-butanol (peak 2), ethanol interference (peak 3), acetone interference (peak 4) and acetone (peak 5) analyzed with (a) refractive index detection (b) UV 210 nm detection (c) UV 265 nm detection, (d) UV 285 nm detection, and concentration profile of the supernatant from a Chlostridium acetobutylicum ABE fermentation of (e) n-butanol, (f) acetone, (g) ethanol, between 0 h and 112 h analyzed with the 50 mm guard column and 300 mm column. HPLC parameters: column temperature 30 °C, mobile phase 5 mM sulfuric acid, flow rate 1.0 mL/min (0.6 mL/min for 300 mm column), refractive index and UV (210 nm, 265 nm, 285 nm) detection