DETERMINATION OF PYRIDOXAL IN HUMAN SERUM BY MATRIX ISOPOTENTIAL SYNCHRONOUS FLUORESCENCE SPECTROMETRY

The determination of pyridoxal in human serum was performed using a fl uorimetric technique that is useful for the determination of compounds in samples with unknown background fluorescence, based on synchronous scans through a trajectory joining points of equal intensity of a flu orescence matrix three-dimensional spectrum. This technique, called ma trix isopotential synchronous fluorescence can be improved by means of the application of derivatives. The determination of pyridoxal in hum an serum was performed with this technique without any prior separatio n steps. The validity, applicability and simplicity of the method were demonstrated. The measurements were performed in aqueous medium at pH 7.0 adjusted by adding 0.05 M phosphate buffer solution. A complete s tatistical analysis of the experimental data was performed and the res ults showed that correlation coefficients are between 0.9901 and 0.995 8 for all the calibration graphs, and in all cases the intercepts on t he ordinate were negligible. The experimental F (1.72) is smaller than theoretical value (3.89) as expected from an analysis of variance. Th e reproducibility of the method was tested and the results were a stan dard deviation of 0.0117 mu g ml(-1) and a relative error of 4.91%.