A new chemiluminescence method for the determination of nickel ion.

A new chemiluminescence (CL) phenomenon described as the second-chemiluminescence (SCL) was observed and a strong CL signal was detected, when Ni(II) ion was injected into the mixture after the end of the reaction of potassium permanganate with alkaline luminol. The possible CL mechanism is proposed based on the kinetic curve of the CL reaction, CL spectra, UV-vis spectra and some other experiments. A flow-injection analysis for the determination of nickle(II) ion has been developed, based on the catalysis of nickel(II) ion on the CL reaction between potassium manganate produced on-line and luminol under alkaline condition. Under the optimum conditions, the SCL intensity is linear with the concentration of nickel(II) ion in the range of 8.0-200.0 microg l-1 and 0.2-2.0 mg l-1. The R.S.D. was 4.5% for 11 determinations of 250 microg l-1 nickel(II) ion and the detection limit (3sigma) for nickel(II) ion was 0.33 microg l-1. The method was applied to determine nickel(II) ion in synthetic samples with satisfactory results.