Pharmacokinetics study of hemin in rats by applying (58)Fe-extrinsically labeling techniques in combination with ICP-MS method.

Iron is a challenging element due to its high background in various matrixes including blood, tissues even in the air and it is urgent to develop a method for the accurate determination of iron in bio-samples. After optimization of mass spectrometric conditions using collision cell technology and compensating for interference using a mathematical correction equation, an inductively coupled plasma mass spectrometry (ICP-MS) method for the quantitative determination of (58)Fe originating from hemin extrinsically labeled avoiding endogenous interference was developed. After a single step of dilution, analysis of each sample was completed within 1.5min. The assay was linear in the concentration range from 0.005 to 1.0μg/ml. The precisions and accuracies determined within three consecutive days were in acceptable limits and there was no significant matrix effect. The optimized method was successfully applied to a pharmacokinetic study of (58)Fe originating from hemin extrinsically labeled and iron absorption measured in rats was 1.07%. Those indicated that extrinsically label techniques in combination with ICP-MS will become a new tool for the analysis of iron preparations and other endogenous substances.