[Process analysis for levulinic acid generated in waste wood liquefaction by non-development thin-layer chromatography based on oblique projection].

A rapid and quantitative method is presented for multi-component process analysis, based on multi-wavelength thin-layer chromatography (TLC) scanning but without the routine development. The samples from the waste wood liquefaction process are applied on silica plates, and just the last sample of spot need to be developed for getting separated spectra. These spectra are divided into two parts of production (levulinic acid) and background, respectively, to build an oblique projection operator. The other process samples do not need to be developed repeatedly, and are scanned to collect hybrid spectra immediately. The pure production spectrum can be separated from the process spectrum by the oblique projection algorithms to realize the production quantification. It was showed that the relative errors between the determination results by this method and those by high performance liquid chromatography (HPLC) were less than 3.27%, and so the consistency is perfect.