Microdetermination of Proteins in the Biological Samples by the Synchronous Fluorescence Method with EDMHT

EDMHT can react with human serum albumin to form a complex compound-protein.It can make intrinsic fluorescence of HSA produce specific change and the synchronous fluorescence intensity of the system was in good proportion to the concentration of protein.Based on this,a new method for the determination of proteins by synchronous fluorescence spectrometry under simulated physiological conditions was established using EDMHT as a molecular probe.The spectral characterization and intensity of synchronous fluorescence were related to the value of Δλ,pH,ionic strength and the order of the reagents.The synchronous fluorescence intensity of the system was in proportion to the concentration of protein in the range of 5.52～276 mg/L for HSA when T=20 ℃,Δλ= 50 nm,Tris-HCl buffer(pH = 7.40) and ionic strength was 0.1 mol/L of NaCl solution.The serum,urine and saliva were determined in the experiment and its recovery was in the range of 95.18%～ 98.32% with RSD of 2.87%.The detection limit was 0.348mg/L(n=11) for HSA.The results suggested that the method possessed characteristics of convinience,rapidity,high sensitivity,broad linear range,better precision and recovery.Above all it had been applied to the determination of proteins in biological samples with satisfactory results.