HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC-FLUORESCENCE DETERMINATION OFTRACES OF SELENIUM IN BIOLOGICAL-MATERIALS

An improved method for the determination of selenium in biological mat erials has been developed. This work both extends and validates the pr ocedure of Vezina and Bleau (J. Chromatog. 426, 385-391, 1988) which i s based on high-performance liquid chromatographic determination of th e fluorophore formed by reaction of Se(IV) with 2,3-diaminonaphthalene . The mass detection limit is 48 pg selenium (3 sigma) and the concent ration detection limits are 48 parts per trillion in biological fluids and 120 to 480 parts per trillion in dried biological materials. The linear dynamic range of the method has been extended up to approximate ly 800 ng. Relative standard deviations of 9.4 to 2.7% were observed i n repeated analyses of standards in the range of 0.5 to 500 ng. The pr oposed method was validated with respect to 23 biological reference ma terials spanning an 1800-fold range of selenium concentrations and was found to be free of significant constant or proportional biases despi te greatly different matrix compositions. This method offers an unsurp assed combination of sensitivity, accuracy, linear dynamic range, and freedom from matrix interferences and may be considered a reference me thod for the reliable determination of selenium in biological material s.