Rapid determination of quinoline and 2-hydroxyquinoline in quinoline biodegradation process by tri-wavelength UV/Vis spectroscopy.

For the present study, a tri-wavelength UV/Vis spectrophotometric method for rapid determination of quinoline (Q) and 2-hydroxyquinoline (HQ) during Q biodegradation was developed. Based on the spectral measurements at 289 nm (the isosbestic point of Q and HQ), 326 and 380 nm, the spectral interference of extracellular polymeric substances (EPS) in the process samples could be minimized, and the amounts of Q and HQ could be simultaneously quantified. Our results indicated that the relative standard deviations in the repeatability tests were 2.7 and 1.7% for Q and HQ, respectively. The method validation was conducted by comparing the data obtained using the present method with those generated from high performance liquid chromatography (HPLC). The same set of samples from Q biodegradation process was used. The relative differences between the two methods were within 10%. In conclusion, the present method is simple, rapid, and suitable for the investigation in Q biodegradation processes.