Determination of Juglone (5-hydroxy 1,4-naphthoquinone) in Pterocarya fraxinifolia by RP-HPLC

A methodfor determination ofjugione in leaves and hulls ofpterocaryafraxinifolia was developed, based on rp-hplc. this compound was extracted from leaves and hulls by chloroform refluxing about 2 hours. the chloroform was evaporated under low pressure at 50 °c to produce a dry residue. the remained materials were dissolved in acetonitrile to be used for determination of this compound. appropriate conditions for rp-hplc were determined using standard of juglone. these conditions include, acetonitrile percentage in mobile phase, ph of mobile phase (phosphate buffer) and temperature of column, which were 50%, 4 and 30°c, respectively. juglone concentration was determined using standard addition method. the concentrations ofjuglone were 2.15, 2. 74,1. 77,j.j2and 0.34 gin 100 g ofdry leaves in may, june, july, august and september 2001, respectively. the content ofjuglone in hulls was 0.44 g in joo g ofdry hulls in may.