The simultaneous spectrophotometric determination of microamts. of molybdenum, tungsten and titanium in mixed system by using CPA-Matrix method of calculation has been investigated. The various optimum conditions of Mo(W,Ti)-salicylfluorone-cetyltrimethylammonium bromide color reaction for simultaneous determination of Mo, W, and Ti have been established. The four criteria for selecting anal. wavelengths for simultaneous determination of multicomponents were proposed. According to the criteria proposed, the six wavelengths 510, 512, 514, 516, 518, 520 nm were chosen in simultaneous determination of Mo, W and Ti. Beer's law is obeyed for Mo 0-0.4 0-1.0, and Ti 0-3.35 mg/mL. Ten mixed samples with arbitrary proportion of Mo, W and Ti were examined by the method with high accuracy and precision.

Key words: SPECTROPHOTOMETRY, XANTHENONE P, C16 COMPOUNDS, SURFACTANTS, MATRIX METHOD, CALCIUM, COLOUR REAGENTS, COMPUTER APPLICATIONS, BROMINE COMPOUNDS, TITANIUM