A sensitive, direct colorimetric assay of serum iron using the chromogen, nitro-PAPS.
A direct colorimetric method is presented for the determination of serum iron in 0.1-ml sized samples, using a new, water-soluble, reagent, 2-(5-Nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol Na salt (epsilon 585 nm = 9.4 X 10(4) l/mol per cm). Interference of copper and zinc in sera can be eliminated entirely by forming copper- and zinc-thioglycollate complexes immediately upon the dissociation of the protein-bound iron, copper and zinc by thioglycollate and sodium dodecyl sulfate. The serum blank was minimized by the use of sodium dodecyl sulfate as a protein denaturant. Within-run and between-run precision (CV) were in the range of 0.7-2.9% and 1.1-3.6%, respectively, depending on the serum iron content. A good correlation (r = 0.995) was obtained between this method and the reference method proposed by the International Committee for Standardization in Hematology.
Makino
T
T
Department of Clinical Chemistry, Kanagawa Prefectural College of Nursing and Medical Technology, Yokohama, Japan.
Kiyonaga
M
M
Kina
K
K
D001391:Azo Compounds; D002863:Chromogenic Compounds; D003124:Colorimetry / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000097:blood*; D012967:Sodium Dodecyl Sulfate; D013053:Spectrophotometry; D013864:Thioglycolates; D014168:Transferrin / Q000378:metabolism
D001391:Azo Compounds; D002863:Chromogenic Compounds; D013864:Thioglycolates; D014168:Transferrin; C055388:2-(5-nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol; D012967:Sodium Dodecyl Sulfate; C017487:2-mercaptoacetate; D007501:Iron