title: Problems in the determination of erythrocyte protoporphyrin by ethyl acetate-acetic acid extraction.
abstract: Three problems with the ethyl acetate-acetic acid method of protoporphyrin analysis were identified: (1) protoporphyrin extraction from whole blood may yield low recoveries in comparison with extraction from prediluted blood; (2) recovery of protoporphyrin is low with some batches of ethyl acetate, but such unsatisfactory reagent can be identified by an iodide oxidation test; (3) protoporphyrin standards prepared with deionised water may be unstable. However, glass-distilled water is satisfactory.
mesh_terms: D000085:Acetates; D004912:Erythrocytes / Q000032:analysis*; D006801:Humans; D007202:Indicators and Reagents / Q000592:standards; D011166:Porphyrins / Q000097:blood*; D011524:Protoporphyrins / Q000097:blood*; D014881:Water Supply / Q000592:standards
chemical_list: D000085:Acetates; D007202:Indicators and Reagents; D011166:Porphyrins; D011524:Protoporphyrins; C007650:ethyl acetate