title: Spectrophotometric determination of water in organic solvents with solvatochromic dyes.
abstract: The correlation between the absorbance at a fixed wave-length of a betaine dye in an organic solvent and the water content of the same solvent has been investigated. The betaine dyes investigated are 2,4,6-triphenyl-N-(3,5-diphenyl-4-hydroxyphenyl)pyiidinium betaine (I), 1-methyl-8-hydroxyquinolinium betaine (II), 1-methyl-6-hydroxyquinolinium betaine (III) and 2-methyl-5-isoquinolinium betaine (IV), and the organic solvents are ethanol, isopropanol, acetone, dioxan, acetonitrile and pyridine. The possibility of determining a trace amount of water in an organic solvent is demonstrated. The sensitivity of the method depends on solvent and dye but for example, 0.06 mg of water in 1 ml of acetonitrile can be detected with III with an ordinary spectrophotometer. The limitations of practical applications are discussed.
authors.affiliation: Department of Organic Synthesis, Faculty of Engineering, Kyushu University, Fukuoka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kumoi
authors.forename: K
authors.initials: K
authors.lastname: Oyama
authors.forename: T
authors.initials: T
authors.lastname: Yano
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Ueno