Time measurement-visual analysis of nickel(II) using autocatalytic reaction with sodium sulfite/hydrogen peroxide...

Trace amounts of nickel(II) can function as a trigger (= reaction initiator) in an autocatalytic reaction with the sodium sulfite/hydrogen peroxide system. Based on this finding, sub-microg L(-1) levels of nickel(II) were determined by a time measurement using the autocatalytic reaction. The detection range using the above method was 10(-9)-10(-5) M, the detection limit (3sigma) was 8.1x10(-10) M (0.047 microg L(-1)), and the relative standard deviation was 2.66% at nickel(II) concentration of 10(-7) M (n = 7). This method was applied to length detection-flow injection analysis. The detection range for the flow injection analysis was 2x10(-9)-2x10(-3) M. The detection limit (3sigma) was 1.4x10(-9) M (0.082 microg L(-1)), and the relative standard deviation was 1.86 at initial nickel(II) concentration of 10(-6) M (n = 7).