Determination of iron in blood serum using flow injection with luminol chemiluminescence detection

A simple and rapid ow injection method is reported for the determination of iron in blood serum after acid digestion with HNO 3 and HClO 4 , based on luminol CL detection in the absence of added oxidant. The detection limit (3 s ) was 1.0 nmol/L with a sample throughput of 120/h. The calibration graph was linear over the range 0.001–1.0 µmol/L ( r 2 = 0.9974), with relative standard deviations (RSD) ( n = 4) in the range 3.2–5%. The effect of interfering cations (Ca(II), Mg(II), Cu(II), Cd(II), Pb(II), Mn(II), Zn(II), Ni(II), Co(II) and Fe(III)) and anions (Cl − , SO 4 2− , HCO 3 − , NO 3 − , NO 2 − ) were studied using a luminol CL system for Fe(II) determination. The method was applied to normal blood serum and the results (1.32 ± 0.08–1.74 ± 0.05 mg/L) were compared with those from a spectrophotometric reference method (1.34 ± 0.06–1.80 ± 0.10 mg/L), which agree fairly well with the overall reference range in blood. Copyright © 2004 John Wiley & Sons, Ltd.