A comparison of photometric methods for serum iron determination under flow analysis conditions

•Three photometric methods for serum iron have been compared.•Optoelectronic flow-through iron detectors have been developed.•MCFA system for serum iron determination has been developed.•The MCFA system is useful for human serum analysis.

In this contribution, a multicommutated flow analysis (MCFA) system for serum iron determination is presented. The construction of the system has enabled sequential measurements with three different determination methods with 1,10-phenantroline, Ferrozine and Ferene S using separate analytical units (modules). For each method a dedicated optoelectronic detector has been developed. Under optimal flow conditions, investigated methods were analytically characterized by linear range and sensitivity: 1.5 − 100.0 μmol L−1 and 4.9 mV L μmol−1, 3.3 − 50.0 μmol L−1 and 6.6 mV L μmol−1, 4.0 − 40.0 μmol L−1 and 13.3 mV L μmol−1 for 1,10-phenantroline, ferrozine and ferene S methods, respectively. In the course of investigations also clinical usefulness of each method has been discussed. The analysis of serum samples proved that Ferrozine and Ferene S methods are sufficient for serum iron determination with relatively low consumption of samples (less than 50 μL of serum).