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The determination of Sb(III) on an ex-situ bismuth screen-printed carbon electrode (ex-situ BiSPCE) by means of adsorptive stripping voltammetry (AdSV) using quercetin-5'-sulfonic acid as chelating agent was optimized. The effect of different experimental parameters such pH, ligand concentration (CQSA), accumulation potential (Eacc) and accumulation time (tacc) were studied to obtain a wide linear range, the highest sensitivity and the lowest detection limit. Ex-situ BiSPCE was analytically compared with a sputtered bismuth screen-printed electrode (BispSPE) under optimal conditions. The obtained analytical parameters suggest that ex-situ BiSPCE behaves much better than BispSPE and the first was selected for this study. Optimal parameters were pH=4.6; CQSA=10.0 to 20.0×10(-6)molL(-1); Eacc=-0.5V and tacc=60s. Peak area is proportional to Sb(III) concentration up to 100.0μgL(-1) (tacc 60s) and 45.0μgL(-1) (tacc 120s) range, with detection limits of 1.2μgL(-)(1) (tacc 60s) and 0.8μgL(-1) (tacc 120s). The relative standard deviation for a Sb(III) solution (20.0μgL(-1)) was 3.9% for ten successive assays. Thus, the effect of various interfering metal ions was studied and the methodology was validated using a spiked groundwater reference material with very satisfactory results.

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A sensitive and selective method for the determination of Sb3+ based on the formation of its complexes with 8‐hydroxyquinoline (HQ) and 8‐hydroxyquinoline‐5‐sulfonic acid (HQS) is proposed. The best analytical conditions are: pH 5.4 and 2.2 for HQ and HQS, respectively; CHQ from 15.0 to 25.0 µmol L−1 and CHQS from 70.0 to 200.0 µmol L−1. The detection limits are 100.0 and 14.0 ng L−1 (tacc=30 s) for Sb3+ with HQ and HQS, respectively. The method using HQS as ligand has a 2.2‐fold higher sensitivity than that with HQ and the former was chosen for Sb3+ determination.