For this purpose, a modified gradient profile based on
Zheng, Thayer, Rao, and Pohl (2009) was used as follows (relative to
the injection at 0 min): 500 mM NaOH from 15.0 min
to 14.0 min, 2.5 mM NaOH from 13.9 min to 24.9 min, and
500mMNaOH from 25.0 min to 35.0 min. To ensure the removal of
concomitant polysaccharides from the column, a blank (water) was
injected after each SAPNDM injection, and the column was washed
excessively after every fourth sample injection.