Quantitative Analysis Of Iron In Protein Bands Existing In Polyacrylamide Gel Matrix With Synchrotron Radiation X-Ray Fluorescence

A procedure has been proposed for quantification of Fe in protein bands in polyacrylamide gel matrix with synchrotron radiation X-ray fluorescence(SRXRF) analysis. Human hemoglobin was separated with isoelectric focusing (IEF), and Fe amounts in protein bands were measured with SRXRF. Calibration standards were prepared by electrophoresis of bovine serum albumin containing known amounts of Fe with stacking gel. The calibration curves can be obtained in a range of 0-5.1ng Fe and linear relationship between dosage of metals and fluorescent intensity can be observed (R-2 = 0.9897). The method provides detection limit of 0.63ng Fe, and the recovery of Fe determination is about 106%. The hyphenated technique of SRXRF and IEF has advantages of quantifying trace elements in proteins and identifying the proteins simultaneously. It can be employed for speciation analysis of trace elements in biological samples.