Acetic acid ch3cooh

All chemical reagents used in this work were of analytical grade, and the solutions were prepared with deionized water type II. A stock solution of 1000 mg Sb(III)/L was prepared from KSbC₄H₄O₇ (99.95% Probus, Barcelona, Spain), the neat chitosan with an average molecular weight of 125,000 g/L and a degree of acetylation of 0.13 (Aber Technologies, Lannilis, France) previously reported [20 (link)], acetic acid (CH₃COOH, 99.7%, Panreac, Barcelona, Spain), sodium borohydride (NaBH₄, ≥96%, Sigma-Aldrich, St. Louis, MO, USA), nitric acid (HNO₃, 69.0%, J.T. Baker, Radnor, USA) sodium chloride (NaCl, 99.5%, Prolabo, Fontenay-sous-Bois, France), and iron(III) chloride (FeCl₃·6H₂O, 99%, Fluka, Buchs, Switzerland).

All chemical solutions were prepared in ultrapure water (18.2 MΩ cm) produced by a Milli-Q water purification system. FIP (98.77 wt%) was acquired from Sinochem Ningbo (Lian Yun Gang City, Jiangsu Province, China). PPB (C₁₀H₁₂O₃, 99 wt%), BP-3 (C₁₄H₁₂O₃, 98 wt%), NTA (C₆H₆NNa₃O₆), EDDS trisodium salt solution (C₁₀H₁₃N₂Na₃O₈) and potassiumtitanium oxide oxalate (C₄K₂O₉Ti·2H₂O, ≥90 wt%) were purchased from Sigma-Aldrich (São Paulo, Brazil). Ferric nitrate nonahydrate (Fe(NO₃)₃·9H₂O), ferrous sulfate heptahydrate (FeSO₄·7H₂O), EDTA disodium salt dihydrate (C₁₀H₁₄N₂O₈Na₂·2H₂O), sodium citrate dihydrate (Na₃C₆H₅O₇·2H₂O), hydrogen peroxide (H₂O₂) (30 wt%), sodium sulfite (Na₂SO₃) and 1.10-phenanthroline (C₁₂H₈N₂·H₂O) were provided by Synth (Diadema, Brazil). Hydroxylamine hydrochloride (NH₂OH·HCl) was obtained from Êxodo (Sumaré, Brazil), HPLC-grade methanol (CH₃OH) was obtained from J. T. Baker (Aparecida de Goiânia, Brazil), acetic acid (CH₃COOH) was obtained from Panreac (Barcelona, Spain) and anhydrous sodium acetate (CH₃COONa) and sulfuric acid (H₂SO₄) were both furnished by Dinâmica (Indaiatuba, Brazil).