An approach to determine nickel in aqueous systems through complexation with a Schiff base based on high‐performance liquid chromatography coupled with photodiode array detector

This study presents a new and rapid analytical high‐performance liquid chromatography coupled with a photodiode array detector method for determining nickel ion (Ni2+) complex with Schiff base (Z)‐1‐(thiophen‐2‐yl‐methyleneamino) propane‐2‐ol easily. The influence of pH, surfactant, and effect of mobile phase on the formation of the Ni‐(Z)‐1‐(thiophen‐2‐yl‐methyleneamino)propane‐2‐ol complex was studied and optimized. The results showed that the acidic condition (pH = 5) favors the complexation most. Triton X‐100 neutral surfactant was used for dissolving the Ni–complex synthesized. A mobile phase ratio of methanol:acetonitrile:water 70:20:10, v/v/v was taken as optimum. This approach allowed the analysis of Ni2+ ion with the limit of detection of 0.0349 ng/mL over the linear range of (0.1–250 ng/mL) and a relative standard deviation of < 2%. The developed method exhibited remarkable extraction recoveries for Ni2+ in various real water samples (tap water; 98.0%–99.8% and river water; 97.0%–98.7%) and alloys with recoveries of (nichrome; 85.2% and chromel; 88.4%). Moreover, this protocol was also applied for the quantitation of Ni2+ in real sewage samples at a concentration level of 0.256 ng/mL. The outcomes of the present work successfully revealed the apparent superiority of Schiff base (Z)‐1‐(thiophen‐2‐yl‐methyleneamino) propane‐2‐ol toward the practical removal of target Ni2+ under real‐world conditions.