Polarography of disodium pentacyanonitrosylferrate(II) : Part 1. Pulse Polarographic Behaviour and Determination at Trace Levels

Abstract The pulse polarographic behaviour of disodium pentacyanonitrosylferrate(II) (sodium nitroprusside) was studied in the pH range 0–9. Maximum sensitivity is obtained in 1 M perchloric acid as a result of coincidence of the first two peaks and enhancement of the second peak. Calibration graphs are linear with conventional and high-performance differential pulse polarography at both the dropping mercury and static mercury drop electrode in the range 4–1000 ng ml −1 (1.3 × 10 −8 -3.3 × 10 −6 M). The estimated detection limits are about 2 ml −1 (7 × 10 −9 M). The reduction product(s) are probably adsorbed at the mercury electrode.