کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1190690 963537 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
FIA potentiometric system based on periodate polymeric membrane sensors for the assessment of ascorbic acid in commercial drinks
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
FIA potentiometric system based on periodate polymeric membrane sensors for the assessment of ascorbic acid in commercial drinks
چکیده انگلیسی

Ascorbic acid is found in many food samples. Its clinical and technological importance demands an easy-to-use, rapid, robust and inexpensive method of analysis. For this purpose, this work proposes a new flow procedure based on the oxidation of ascorbic acid by periodate. A new potentiometric periodate sensor was constructed to monitor this reaction. The selective membranes were of PVC with porphyrin-based sensing systems and a lipophilic cation as additive. The sensor displayed a near-Nernstian response for periodate over 1.0 × 10−2–6.0 × 10−6 M, with an anionic slope of 73.9 ± 0.9 mV decade−1. It was pH independent in acidic media and presented good selectivity features towards several inorganic anions. The flow set-up operated in double-channel, carrying a 5.0 × 10−4 M IO4- solution and a suitable buffer; these were mixed in a 50-cm reaction coil. The overall flow rate was 7 ml min−1 and the injection volume 70 μl. Under these conditions, a linear behaviour against concentration was observed for 17.7–194.0 μg ml−1, presenting slopes of 0.169 mV (mg/l)−1, a reproducibility of ±1.1 mV (n = 5), and a sampling rate of ∼96 samples h−1. The proposed method was applied to the analysis of beverages and pharmaceuticals.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 120, Issue 3, 1 June 2010, Pages 934–939
نویسندگان
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