Multivariate optimization of differential pulse polarographic–catalytic hydrogen wave technique for the determination of nickel(II) in real samples

摘要: Abstract Multivariate optimized experimental conditions were established for the determination of nickel(II) in 92 grape samples after complexation with ammonium piperidine dithiocarbamate (APDC) and morpholine (AMDC). Differential pulse polarographic (DPP) studies wave characteristics indicated that it is catalytic hydrogen (CHW) type sensitive to pH, concentration scan rates. A single, sharp peak obtained at −1.22 V allowed trace range 3.2 × 10 −6 1.17 × 10 −3  M a linear calibration detection limit 1.8 × 10 2.7 × 10 APDC AMDC respectively. Mechanistic aspects between APDC/AMDC confirmed cyclic voltammetry supported by theoretical calculations. The DFT calculations adduct reveal smaller HOMO–LUMO energy gap than adduct, suggesting has greater tendency act as an electron donor.