Abstract
Flow injection analysis (FIA) was applied to the determination of organic phosphates such as phosphoamino acids and nucleotides. Under the optimized condition, organic phosphates were heated in a hydrolysis coil at 170°C in 2.0Msulfuric acid for 5.8min, most of organic phosphates being hydrolyzed at the rate of over 80%. The resultant orthophosphate was monitored at 830nm after the selective reaction with a molybdenum reagent. When 50μM O-phospho-DL-tyrosine solution was employed (injection volume: 5μl), the present FIA method enabled the analysis of 20 samples h-1 with a relative standard deviation of 2.6% (n=20). The detection limits (S/N=2) of organic phosphates were ca. 50pmol. The present FIA system is expected to be useful as a postcolumn reaction detector for high-performance liquid chromatography of organic phosphates.
