Hello Fiaz, 

It depends on your pre-treatment strategy, different pre-treatment strategies have different optimal conditions (temp, pressure, time etc). The optimum condition for it pretreatment strategy is most often determined empirically. It is difficult to rationally determine the response of any biomass to a pretreatment condition without some form of empirical data. With respect to Klason lignin preparation, I am not how the biomass will respond. However, I suspect that your hydrolysis will  be incomplete leading to over-estimation of lignin acid-insoluble (Klason) lignin and under-estimation of sugar content, particularly glucan. I hope this helps. Thanks.

Hello Fiaz,

In the paper you referred to, the authors employed a two-step hydrolysis strategy to ensure complete estimation of the sugar content of the biomass. First, they hydrolyzed the biomass (corn stover) in H2SO4 at 121oC for 60 min, and subsequently did a second hydrolysis of the filter liquor at 121oC for 10 min to ensure depolymerization of any residual polysaccharide. I felt they carried out the hydrolysis for 10 min to reduce caramelization of the hydrolyzed sugar monomers. I have applied similar two-step strategy to remove residual polysaccharide from the acid-insoluble lignin fraction, but I did my hydrolysis for 60 min! 

http://www.rsc.org/suppdata/c6/ra/c6ra04443c/c6ra04443c1.pdf

Thank you Joshua, I will test for 10 min n 60 min to determine which will be suitable in my case.

Dear Joshua,

Hydrolysis duration also depends  acid concentration.