. Author manuscript; available in PMC: 2022 Jan 4.

Published in final edited form as: J Chromatogr A. 2020 Nov 13;1635:461705. doi: 10.1016/j.chroma.2020.461705

Table 2.

Final optimized conditions of the new two-step orthogonal chromatographic purification process for QS-21 developed in this study. FA: formic acid, AA: ammonium acetate.

	Column	Flowrate (mL/min)	Injection Volume	Sample Concentration (mg/mL)	Condition	Purity	Yield	Solvent Consumption/Injection	Time /Injection (min)
First Step	Luna Omega Polar C18 (250 × 50 mm, 5 μm, 100 Å)	85	mL	100	Gradient: 40–45% MeCN with 0.1% FA	–	~ 4%	2.05 L MeCN 2.28 H ₂ O	53
Second Step	Syncronis HILIC (250 × 21.2 mm, 5 μm, 100 Å)	20	μL	40	Isocratic: 80:20 MeCN:H ₂ O with 5 mM AA (pH 5.8)	˃ 97%	˃ 2%	0.50 L MeCN 0.15 H ₂ O	30