According to the United States Pharmacopeia and the National Formulary (USP 40-NF 35*), measurement of apparent weight-average molecular weight (Mw) and polydispersity of polyethylene glycol 3350 should be carried out with a column filled with L37 packing material and meets following requirements. The OHpak SB-803 HQ confirmed the requirements were met (obtained Mw of USP Polyethylene Glycol 3350 ref. standard was about 3,360).

Requirements:
　Apparent weight-average molecular weight: 3,015 to 3,685 g/mol
　Polydispersity: 90% to 110% of the value stated on the label or within the range indicated on the label

*The version at the time of the application acquisition. 


Sample : 10 μL
1.0 mg/mL each in H₂O
1. Polyethylene glycol 3350
2. Polyethylene glycol standard
(Mp; 6,420)
3. Polyethylene glycol standard
(Mp; 4,120)
4. Polyethylene glycol standard
(Mp; 3,420)
5. Polyethylene glycol standard
(Mp; 2,010)
6. Polyethylene glycol standard
(Mp; 970)

Column       : Shodex OHpak SB-803 HQ (8.0 mm I.D. x 300 mm)
Eluent       : H2O
Flow rate    : 0.8 mL/min
Detector     : RI
Column temp. : 35 °C