A new rapid, selective and sensitive on-line microwave flow injection-kinetic method was developed for spectrophotometric determination of micro amounts of Ir(Ⅲ), based on its catalytic effect on the m-acetylchlorophosphonazo (CPA-mA) and KIO4 reaction in NaOH media. An on-line microwave oven was employed to accelerate the reaction. The reaction was followed spectrophotometrically by measuring the decrease of the absorbance of CPA-mA at 580 nm. The effect of five variables for the determination of Ir(Ⅲ) was optimized by means of a multilayer artificial neural network using extended deltabar-delta (EDBD) algorithms. Under the optimum experimental conditions, Ir(Ⅲ) could be determined in the range 0.060-0.60 μgZZZ; mL-1 with detection limit of 0.02 μgZZZ;mL-1 and the sampling frequency of 34 h-1. The proposed method was applied to the determination of micro amounts of Ir(Ⅲ) in refined ore and secondary alloy with the recoveries from 91.4% to 109%.

A new method is proposed for the spectrophotometric determination of Pd(Ⅱ), based on the reaction of Pd(Ⅱ) with 2-(4-chloro-2-phosphonophenylazo)-7-(3-carboxyphenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid(CPA-mK) in sulfuric acid without heating. Beer's law is obeyed for 1.0-4.0 mg of Pd (Ⅱ) in 10 mL of solution. The calibration curve from 1.0 to 42.0mg in 10mL of solution is modeled successfully by artificial neural networks (ANNs). The maximum relative error between experimental values and the values predicted by ANNs is 1.5%. In comparison with some mathematical functions, ANNs show better ability for curve fitting, thus greatly extending the applicable range of the calibration curve of this new system. The method has been applied to determine Pd (Ⅱ) in ore and catalyst samples with a relative error of less than 4% and with a recovery range between 94% and 103%.