Study of effect of sample composition on flame atomic absorption determination of rhenium, tungsten and molybdenum using mathematical experiment design

Using the method of orthogonal experiment design, mutual effects of Re, W, and Mo during atomic absorption (AA) determination in complex solutions have been studied. A spectroscopic buffer has been found (500 μg A/ml+5.8% H3PO4 in the test solution) which eliminates the mutual effects of Re, W, and Mo as well as other elements (Ca, Mg, Ti, Na, Sn, Fe). This allows direct AA determination of Re, Mo, W in one and the same sample without their preseparation and separation from concomitants using nitrous oxide-acetylene and air-acetylene (in the case of Mo) flames. The relative errors of Re, Mo and W determination are presented for the case of buffer use and without it