Phthalic anhydride solution: Place

Phthalic anhydride solution: Place 49.0 g of phthalic anhydride into an amber bottle, and dissolve in 300 mL of pyridine from a freshly opened bottle or pyridine that has been freshly distilled over phthalic anhydrideSample solution for liquid polyethylene glycols: Carefully introduce 25.0 mL of the Phthalic anhydride solution into a dry, heat-resistant pressure bottle. Add an amount of the specimen equivalent to its expected average molecular weight divided by 160. Insert the stopper in the bottle, and wrap it securely in a cloth bag