کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10560063 | 969703 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Sequential fluorometric quantification of malic acid enantiomers by a single line flow-injection system using immobilized-enzyme reactors
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
A method for the sequential enantiomeric quantification of d-malate and l-malate by a single line flow-injection analysis was developed using immobilized-enzyme reactors and fluorescence detection. An immobilized d-malate dehydrogenase (d-MDH) reactor and an immobilized l-malate dehydrogenase (l-MDH) reactor were introduced into the flow line in series. Sample and coenzyme (NAD+ or NADP+) were injected into the flow line by an open sandwich method. d-Malate was selectively oxidized by d-MDH when NAD+ was injected with a sample. When NADP+ was injected with a sample, l-malate was oxidized only by l-MDH. NADH or NADPH produced by the immobilized-enzyme reactors was monitored fluorometrically at 455Â nm (excitation at 340Â nm). Linear relationships between the responses and concentrations of d-malate and l-malate were observed in the ranges of 1 Ã 10â6-1 Ã 10â4Â M and 1 Ã 10â6-2 Ã 10â4Â M, respectively. The relative standard deviations for ten successive injections were less than 2% at the 0.1Â mM level. This analytical method was applied to the sequential quantification of d-malate and l-malate in fruit juices and soft drinks, and the results showed good agreement with those obtained using conventional method (F-kit method).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Talanta - Volume 65, Issue 2, 30 January 2005, Pages 396-401
Journal: Talanta - Volume 65, Issue 2, 30 January 2005, Pages 396-401
نویسندگان
Tadayuki Tsukatani, Kiyoshi Matsumoto,