Simultaneous spectrophotometric determination of phosphate and silicate by using partial least squares method

A very sensitive, simple and selective spectrophotometric method for simultaneous determination ofphosphate and silicate based on formation of phospho- and silicomolybdenum blue complexes in thepresence of ascorbic acid is described. Although the complexes of phosphate and silicate with reagentshow a spectral overlap, they have been simultaneously determined by partial least squares (PLS). Thelinear range was 0.01-2.80 μg ml-1 for phosphate and 0.02-3.00 μg ml-1 for silicate. Interference effectsof common anions and cations were studied and the proposed method was also applied satisfactorily tothe determination of phosphate and silicate in synthetic detergents