Guard column for Shodex OHpak SB series. Shipping solvent is 0.02% NaN3 (sodium azide) and can be replaced with 100% DMF for the analysis of polar polymers. pH range 3-10. Maximum concentration for other solvents is 100% methanol and 75% acetonitrile. Requires coupler 220-91524-97. Use 220-91668-01 for the SB-807 HQ guard column.