Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.14/6769
Título: A sequential injection system for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples
Autor: Mesquita, Raquel B. R.
Data: 2004
Editora: The Japan Society for Analytical Chemistry
Citação: "Analytical Sciences" . ISSN 0910-6340. 20: 8 (2004) 1205-1210
Resumo: A sequential injection methodology for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples is proposed. A single manifold is used for the determination of the three analytes, and the same protocol sequence allows the sequential determination of calcium and magnesium (the sum corresponds to the water hardness). The determination of both metals is based on their reaction with cresolphtalein complexone; mutual interference is minimized by using 8-hydroxyquinoline for the determination of calcium and ethylene glycol-bis(0-aminoethyl ether)- N,N,N',N'-tetraacetic acid (EGTA) for the determination of magnesium. Alkalinity determination is based on a reaction with acetic acid, and corresponding color change of Bromcresol Green. Working ranges of 0.5 - 5 mg dm” for Ca, 0.5 - 10 mg dm” for Mg, and 10 - 100 mg HCO3’ dm’3, for alkalinity have been achieved. The results for water samples were comparable to those of the reference methods and to a certified reference water sample. RSDs lower than 5% were obtained, a low reagent consumption and a reduced volume of effluent have been accomplished. The determination rate for calcium and magnesium is 80 h’1, corresponding to 40 h’1 per element, while 65 determinations of alkalinity per hour could be carried out.
Peer review: yes
URI: http://hdl.handle.net/10400.14/6769
Versão do Editor: http://www.jstage.jst.go.jp/article/analsci/20/8/20_1205/_article
Aparece nas colecções:ESB - Artigos em revistas internacionais com Arbitragem / Papers in international journals with Peer-review



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