Determination of iron, cobalt, copper, zinc and manganese in water by solid phase extraction and high performance liquid chromatography

A method for the determination of iron, cobalt,, copper, zinc and manganese by solid phase extraction-high performance liquid chromatography was studied. The iron, cobalt, copper, zinc and manganese ions were pre-column derived by tera-(4-methoxyphenyl)-porphine (TMPP). These chelates can be enriched by solid phase extraction with Waters Sep-Pak-C-18 cartridge. By eluting the retained chelates from cartridge with N,N'-dimethylformamide, the enrichment factor of 50 was achieved. The chelates were separated on a Waters Xterra(TM) RP18 column (3.9 mm x 150 mm, 5 mm) by gradient elution with methanol and tetrahydrofuran as mobile phase at a flow rate of 1.0 mL/min and detected with photodiode array detector from 350 similar to 600 nm. The detection limits of iron, cobalt, copper, zinc and manganese are 3.2 ng/L, 1.8 ng/L, 2.0 ng/L, 2.0 ng/L and 4.5 ng/L respectively. This method has been applied to the determination of iron, cobalt, copper, zinc and manganese in water with good results.