Table 1.

Analytical conditions for analyzing of total PEG concentration and each individual PEG homolog.

Analyte	Chromatography column	Column temperature (°C)	Solvent A	Solvent B	Gradient program	Flow rate (mL/min)
PEG 750	Zorbax 300SB-C18 column (150 mm × 4.6 mm, 5 μm, 300 Å, Agilent)	40	0.1% Formic acid in water	ACN	0–1 min 10% B	0.6
					1–3 min 10%–90% B,
					3–5.5 min 90% B,
					5.5–5.6 min 90%–10% B
					5.6–8 min 10% B
PEG 2000 PEG 5000	Zorbax 300SB-C18 column (150 mm × 4.6 mm, 5 μm, 300 Å, Agilent)	40	0.1% Formic acid in water	ACN	0–1 min 20% B,
					1–5 min 20%–95% B,
					5–7.9 min 95% B,
					7.9–8 min 95%–20% B,
					8–10 min 20% B
PEG 20,000	PLRP-S column (50 mm × 4.6 mm, 8 μm, 1000 Å, Agilent)	55	0.1% Formic acid in water	ACN:isopropanol (50:50)	0–1 min 20% B,
					1–4.5 min 20%–80% B,
					4.5–6.9 min 80% B,
					6.9–7 min 80%–20% B,
					7–9 min 20% B.
MW profiling	Zorbax 300SB-C18 column (150 mm × 4.6 mm, 5 μm, 300 Å, Agilent)	30	0.1% Formic acid in water	0.1% Formic acid ACN	0–1 min 17% B;	0.8
					1–10 min 17%–30% B;
					10–22 min 30%–33% B;
					22–24 min 33%–80% B;
					24–26 min 80% B;
					26–26.1 min 80%–17%B;
					26.1–30 min 17% B