Ultra‐sensitive Voltammetric Aluminum Determination on a Solid Bismuth Electrode for Water Filter Verification

Abstract

This work presents a new ultra‐sensitive method of Al(III) as Al‐cupferron complex voltammetric determination, in 0.04 M ammonium sulfate of pH=6.1 and 0.003 M cupferron by environmentally friendly and durable Bismuth Bulk Annular Band Electrode (BiABE). The optimal measuring parameters include: potential window from −700 to −1250 mV versus Ag|AgCl, preconcentration time and potential of 120 s, −700 mV, respectively. The electrode surface can be activated by fast in situ method: applying short conditioning by the potential of −1300 mV. The best obtained analytical parameters are: range of linearity 0.2–1.2 μg L−1 with high sensitivity of 1.333 μA/μg L−1, limit of detection 0.04 μg L−1 and repeatability below 2.3 %. The described procedure was verified using various CRMs, i. e. surface waters, waste waters and tea leaves. Satisfactory recovery values were obtained in the interval 99.2–103.5 %. Developed DPV procedure was used to determine Al in tap and natural waters in aspect of recovery of aluminum, which was added to the samples. For the first time, we tested also Al removal efficiency from water by the water filters mounted in the trip bottle.