Dispersion behaviour of chromogenic reagents in a microwave field in a flow system. Application to the spectrophotometric flow-injection determination of palladium and rhodium

✍ Scribed by Yanjun Xu; Xingguo Chen; Zhide Hu

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 767 KB
• Volume: 292
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00008-5

✦ Synopsis

Microwave heating associated with flow-injktion @I) analysis was used to expand the field of application of FI analysis. A laboratory-made microwave-irradiation flow-injection analyser and a chromogenic reagent, 4_(5chloro-2-pyridylazo)_l,3-diaminobenzene (5X1-PADAB), were used to establish an FI spectrophotometric method for the sequential determination of Pd and Rh. The relationship between the dispersion coefficient D of various chromogenic reagents and the microwave irradiation time, t,, was established as D = u + bf,/(t, + c), where a, b and c are constants. The .relationship between D and the molecular weight M of the solvent (methanol, ethanol, propan-l-1, propan-2-o1, butan-l-o1 and pentan-l-o11 was found to be D = a' + b'M, where a' and b' are constants. The effect of microwave irradiation on the coordination reactions between 5Cl-PADAB and Pd, Rh, Ru, OS, Ir and Pt was studied.