title: Substoichiometric isotope dilution mass spectrometry of boron by the ion-pair extraction with halogenated salicyl alcohol derivatives and a quaternary ammonium salt.
abstract: Novel salicyl alcohol derivatives (H(2)X(n)sal), 5-bromo-, 3,5-dibromo-, and 3,5-diiodosalicyl alcohol which were abbreviated to H(2)Brsal, H(2)Br(2)sal, and H(2)I(2)sal, respectively, were synthesized and used for the selective extraction of boric acid.  Boric acid was extracted with each H(2)X(n)sal into chlorobenzene containing trioctylmethylammonium chloride (TOMACl) as an ion-pair complex, TOMA·B(X(n)sal)(2), at a different pH range.  The extraction constant (K(ex)) of boric acid was determined by the equilibrium analyses including the formation of hydrogen-bonded complex of each H(2)X(n)sal with TOMACl in the organic phase.  The K(ex) values obtained by salicyl alcohol (H(2)sal) and its derivatives were decreased in the order of H(2)I(2)sal ≥ H(2)Br(2)sal > H(2)Brsal > H(2)sal.  The most powerful extractant, H(2)I(2)sal, was employed for the substoichiometric extraction of boric acid, which was extracted at pH 5 - 9 with a substoichiometric amount of TOMACl in the presence of an excess of H(2)I(2)sal.  The present substoichiometric separation method combined with the stable isotope dilution analysis using inductively coupled plasma mass spectrometry (ICP-MS) could be successfully applied to the determination of boron in a reference material of high-analysis compound fertilizer (FAMIC-A-08) without any correction as to the isotopic abundance.
authors.affiliation: Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Morita
authors.forename: Hisanori
authors.initials: H
authors.lastname: Imura
mesh_terms: D001592:Benzyl Alcohols / Q000737:chemistry*; D001888:Boric Acids / Q000737:chemistry / Q000302:isolation & purification; D001895:Boron / Q000737:chemistry* / Q000302:isolation & purification*; D002722:Chlorobenzenes / Q000737:chemistry; D054879:Halogenation; D006860:Hydrogen Bonding; D013058:Mass Spectrometry / Q000379:methods* / Q000592:standards; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results; D012492:Salts / Q000737:chemistry*
chemical_list: D001592:Benzyl Alcohols; D001888:Boric Acids; D002722:Chlorobenzenes; D000644:Quaternary Ammonium Compounds; D012492:Salts; C037759:trioctylmethylammonium; C010631:salicyl alcohol; C031294:chlorobenzene; D001895:Boron; C032688:boric acid