Simultaneous Determination of Ruthenium and Zinc in Catalysts for Hydrogenation of Benzene to Cyclohexene Using Sodium Peroxide Fusion Sample Digestion and ICP-OES

A novel method for simultaneous determination of ruthenium and zinc in catalysts for hydrogenation of benzene to cyclohexene was established by inductively coupled plasma optical emission spectrometry after sample digestion by high temperature fusion with Na2O2. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of Na2O2and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru and Zn for tested solutions were 11 and 13 ng mL-1, respectively. The relative standard deviations (RSDs) for Ru and Zn were 2.01 and 2.35 % (CRu, Zn= 1 mg L-1, n = 7), respectively. The linear ranges of calibration graphs for Ru and Zn were 0.05 ~ 100.00 mg L-1and 0.04 ~ 50.00 mg L-1, respectively. The proposed method was applied to determine catalyst samples with good recoveries and satisfactory results.