Colour Reaction of Dibromo-p-chloro-chlorophosphonazo with Magnesium(II) and Analytical Application

摘要

Using a complex colour reaction of DBC-chlorophosphonazo with magnesium(II), a spectrophotometric method for the determination of magnesium(II) has been developed. The apparent moiar absorptivity of method is ε_(620 nm) = 2.03 x 10~4 L·mol~(-1)· cm~(-1). Beer's law is followed over the range of 0-1.2 μg/mL for magnesium(E). Its regression equation is: A = 0.1604C (C:μg/mL) + 0.0079, with a correlation coefficient of r = 0.9993. The method has been satisfactorily applied to the determination of magnesium(II) in tobacco samples.