Study of the catalytic polarographic reduction of Ni(II) in the presence of albumin, immunoglobulins and serum proteins Determination of total proteins in serum

✍ Scribed by A.Sanchez Perez; J.E.Fuentes de Frutos

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 572 KB
• Volume: 317
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(95)00425-4

✦ Synopsis

A study on the catalytic reduction of nickel(H) ion in the presence of albumin, immunoglobulins and serum proteins in sodium acetate medium has been carried out using differential-pulse polarography. The catalytic reduction of nickel ion gives two peaks at -0.60 V and -0.78 V versus a saturated calomel reference electrode. The adsorption of proteins on the electrode surface and the formation of Ni(II)-protein complexes, which greatly reduces the high overvolrdge for the polarographic reduction of nickel(U), is shown. The peak obtained at -0.60 V is sufficiently well-defined and can be exploited for analytical purposes. The electrochemical variables affecting the polarographic behavior of nickel(H) in the presence of proteins were investigated; the prepeak obtained at -0.60 V using lop2 M Ni(I1) in 1 M sodium acetate, at pH 8.3, permits the quantitative determination of proteins in the following ranges: 3-75 pg/ml of albumin, 6-175 pg/ml of immunoglobulins and 2-5 pg/ml total serum proteins. Application of the proposed method for rapid and direct determination of total proteins in human serum samples is demonstrated; the results agree with those obtained with the established biuret automated method.