UV-Spectrophotometric and Fluorophotometric Study on Stability of Epinephrine Under Different pH Conditions

Under simulated physiological condition of pH 7.45 with PBS and saline water,the energy transmission of electron pair in epinephrine molecules and the effect of different pH conditions on the stability of epinephrine were studied by UV-spectrophotometry and fluorophotometry. Characteristic absorption peak of epinephrine was observed at wavelength of 278.0 nm,and fluorescence emission wavelength was found at 314.0 nm and 616.0 nm when excited at wavelength of 279.0 nm. A method of fluorophotometric determination of epinephrine was proposed with its linearity range within 1.80 mg·L-1 and detection limit (S/N=3) of 2.70×10-4mg·L-1. It was found that at acidity over pH 10,epinephrine was oxidized by oxygen to form carbonyl compound,leading to bathochromic shift of its absorption peak and weakening or disappearance of its fluorescence peaks.