Dear Pankaj, Apart from the theoretical explanation regarding the FTIR principle, can you clarify with a concrete example or by presenting articles that indicate how FTIR is helpful for the qualitative and quantitative analysis of biomass in bioremedation processes? We have FTIR equipment in our institute and I am very interested to know how I can integrate FTIR analysis into AD fermentation tests. I read articles and some theory about FTIR principle, I know that FTIR indicates the formation and degradation of the compounds by the groups they contain (carbonyl, carboxyl, hydroxyl, etc.). More precisely it indicates the conversion of organic compounds (instability or alteration of materials) and allows the monitoring of the biodegradation stages during fermentation. But this material alteration is undeniable and very evident also by changes in visual aspect, methabolic gases profile etc. It is well known that in AD organic matter undergoes four decomposition stages (hydrolysis, acidogenesis, acetogenesis, methanogenesis), and FTIR will just confirm the conversion of carbonyl to carboxyl functional groups, that is the transition from hydrolysis to acidogenesis. But I do not know for instance if FTIR can separate the different species of carbonyl or carboxyl; I read that it indicates the total area of ​​the functional groups. Can you make qualitative and quantitative difference between propionic and butyric acid for example? This information would be useful in AD, knowing that a higher concentration of propionic indicates the movement towards CH4, while butyric acid indicates the progression of the process towards the formation of CO2. Also, can FTIR be useful in batch tests when you can not sample slurry during the fermentation stages? After all these questions, I conclude with the conclusion read in an article that FTIR is not a sufficient method for indicating material degradation, but must be supplemented by GC-MS and other chemical and microbiological methods. If you or anybody else have published anything on the FTIR use for biomass-to-biogas research, I would be grateful if you would send me some references. Thank you!

I do not know the use of FTIR Spectrum or its interpretation in environmental research (i.e. for analysis of water, sediment and biota)