Flow-injection determination of manganese (II) using surfactant enhanced diperiodatonickelate (IV)-rhodamine 6G chemiluminescence

Chemiluminescence (CL) of the rhodamine 6-G-diperiodatonickelate (IV) (Rh6-G-Ni(IV) complex) in the presence of Brij-35 was examined in an alkaline medium and implemented using flow-injection analysis to analyze Mn(II) in natural waters. Brij-35 was identified as the surfactant of choice that enhanced CL intensity by about 62% of the reaction. The calibration curves were linear in the range 1.7 x 10(-3) - 0.2 (0.9990, n = 7) and 8.0 x 10(-4) - 0.1 mu g ml(-1) (0.9990, n = 7) with limits of detection (LODs) (S:N = 3) of 5.0 x 10(-4) and 2.4 x 10(-4) mu g ml(-1) without and with using an in-line 8-hydroxyquinoline (8-HQ) resin mini-column, respectively. The sample throughput and relative standard deviation were 200 h(-1) and 1.7-2.2% in the range studied respectively. Mn(II) concentrations in certified reference materials and natural water samples was successfully determined. A brief discussion about the possible CL reaction mechanism is also given. In addition, analysis of V(III), Cr(III) and Fe(II) was also performed without and with using an in-line 8-HQ column and selective elution of each metal ion was achieved by adjusting the pH of the sample carrier stream with aqueous HCl solution.