Fourth Derivative Spectrophotometry in Simultaneous Determination of Calcium and Magnesium in Mixture

Abstract

The study included determination of calcium and magnesium in mixture by using 4th–derivative spectrophotometry. The method is based on the red complexes formed by both metal ions with PURPURATE (MUREXIDE ) indicator (violet in colour )in alkaline ethanol – water mixture .The range of application were between 0 to 2.4 µg / ml and between 0 to 1.4 µg / ml at 502 &465 nm for calcium and magnesium respectively. A statistical evaluation of the experimental results was reported.