Abstract: During the purification of pharmaceutical grade crosslinked hemoglobin mixtures of crosslinked and uncrosslinked hemoglobin are heated in the presence of nonstoichiometric amounts of oxygen, resulting in the selective precipitation of the uncrosslinked hemoglobin. After separation of the precipitated uncrosslinked tetramers, the crosslinked hemoglobin remaining in the supernatant is so purified that a further chromatography purification step is unnecessary. This hemoglobin is highly crosslinked absolutely free of chromatography fines, and has a low methemoglobin content.

Abstract: An apparatus for removing liquid and residue from a web of film is provided. The apparatus includes an exhaust tube having an inlet and an outlet, the web of film passing through the exhaust tube from the inlet through the outlet, the exhaust tube being under a negative pressure. Two air knives are located above the outlet of the exhaust tube, one air knife being located on a first side of the film and second air knife being located on a second side of the film, the air knives include a plurality of holes for directing a gas for removing the liquid and residue onto the web of film. The exhaust tube cooperates with the air knives to capture a portion of the removed liquid and residue.