Shodex Column Selection for SEC/GPC Analysis of Sodium Lignosulfonate

Record: 526

Category: Column Selection
Product: KS or SB series
Sample: Sodium Lignosulfonate

Question
A customer would like to characterize the molecular weight of lignosulfonic acid sodium salt by GPC/SEC. Literature suggests that sodium lignosulfonate can be difficult to analyze because it may adsorb to many SEC columns. What Shodex column can be recommended?

Answer
Sodium lignosulfonate is a water-soluble, negatively charged polymer, so both column selection and eluent composition are important for minimizing adsorption and secondary ionic interactions.

Shodex SUGAR KS series columns may be an easy first screening option under simple aqueous or sodium-salt SEC conditions. However, KS columns have limited mobile phase flexibility. If adsorption, poor recovery, or poor peak shape occurs, there are fewer options for method adjustment.

Shodex OHpak SB series columns are generally preferred when method optimization is expected. The SB series provides broader flexibility in salt concentration, pH, and limited organic modifier, which can be useful for difficult charged polymers such as sodium lignosulfonate.

Column pore size should be selected based on the expected molecular weight range of the sample. If the molecular weight range is unknown or broad, screening more than one pore size may be needed.

Shodex does not currently list a dedicated sodium lignosulfonate application. Related references for lignin-family biomass materials and aqueous SEC column selection may be useful starting points.

For more tailored recommendations, please contact Shodex technical support, support@shodexhplc.com, with details on the expected molecular weight range, sample concentration, eluent conditions, detector type, and any SEC columns previously tested.

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