1ST DERIVATIVE SPECTROPHOTOMETRY FOR INDIVIDUAL AND SIMULTANEOUS DETERMINATION OF MAGNESIUM(II) AND COPPER(II) USING EMODIN(1,3,8-TRIHYDROXY-6-METHYLANTHRAQUINONE) AS REAGENT

First derivative spectrophotometry are presented in comparison with si mple spectrophotometric method for Cu(II) and Mg(II) determination wit h emodin in alkaline pH range. The molar absorptivity at the lambda(ma x) of 572 nm and 553 nm for Cu(II) and Mg(II) are 5.5 x 10(3) and 3.9 x 10(3) lit/mol/cm, respectively. Zero crossing measurement technique is found suitable for the simultaneous determination of the metal ions . The interference effects, statistical analyses and limits of detecti on are also reported.