| View Larger Image | Sequential injection spectrophotometric determination of orthophosphate in beverages, wastewaters and urine samples by electrogeneration of molybdenum ... [An article from: Analytica Chimica Acta] | Digitalby F. Mas-Torres (Author), J.M. Estela (Author), M. Miro (Author), A. Cladera (Author), C (Author)
| List Price: | $8.95 | | | Available: | Available for download now |
| | Binding: | Digital | | Publisher: | Elsevier | | Publication Date: | May 10, 2004 |
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EDITORIAL REVIEWS | Product Description This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.Description: A novel and automated sequential injection procedure is proposed for the spectrophotometric determination of orthophosphate without requiring unstable chemical reducing species used in the classical molybdenum blue method. The flowing methodology is based on the on-line generation of the detectable species by electrochemical reduction of the 12-molybdophosphoric acid complex using a stainless steel tubular flow-through working electrode. The established method is linear up to 20mg/l P, with coefficients of variation (n=10) of 2.4 and 1.8% for 2.0 and 10mg/l P, respectively. The versatility of the sequential injection method to analyse samples containing high orthophosphate levels has been demonstrated by the implementation of a dilution chamber as well as flow-reversal techniques, yielding relative standard deviations (n=17) better than 2.0% for standards containing 200 and 800mg/l P. The proposed analyser features an extremely wide dynamic range (viz., 0.3-800mg/l) as well as improved tolerance to silicate interference, so that Si/P ratios higher than 50 are tolerated at the 5% level. Electrochemical conditions, reagent concentrations and physical variables have been thoroughly investigated. The method has been applied to the determination of orthophosphate in wastewaters as well as beverages and biological samples containing high concentrations of the target analyte. The t-test comparison of the means for the developed sequential injection system with electroreduction and both the molybdenum blue classical spectrophotometric batch procedure and inductively coupled plasma-optical emission spectrometric detection selected as external reference methods revealed that there is no evidence of significant differences between the obtained results at the 95% confidence level. |
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