Simultaneous spectrophotometric determination of nitrite nitrate by flow-injection analysis
Φόρτωση...
Ημερομηνία
Συγγραφείς
Ahmed, M. J.
Stalikas, C. D.
TzouwaraKarayanni, S. M.
Karayannis, M. I.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Talanta
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
An automatic direct spectrophotometric method for the simultaneous determination of nitrite and nitrate by flow-injection analysis has been developed. Nitrite reacts with 3-nitroaniline in the presence of hydrochloric acid (0.96-1.8 M HCl or pH 0.5-0.7) to form a diazonium cation, which is subsequently coupled with N-(1-naphthyl)ethylenediamine dihydrochloride to form a stable purple azo dye, the absorbance of which is measured at 535 nm. Nitrate is reduced on-line to nitrite in a copper-coated cadmium column which is then treated with azo dye reagent and the absorbance due to the sum of nitrite and nitrate is measured; nitrate is determined from the difference in absorbance values. A copper column incorporated into the reaction manifold before the copperised cadmium column not only improves the long-term accuracy, but also extends the life time of the copperised cadmium column. Various analytical parameters, such as effect of acidity (pH), flow rate, sample size, dispersion coefficient, time, temperature, reagent concentration and interfering species, were studied. The calibration graphs were rectilinear for 0.1-3.5 mu g ml(-1) of NO3- and 10 ng ml(-1)-2.2 mu g ml(-1) of NO2-. The method is successfully applied to some food samples (meat, flour and cheese), environmental waters (inland and surface), beer and soil samples. Up to 30 samples can be analysed per hour with a relative precision of approximate to 0.1-2%.
Περιγραφή
Λέξεις-κλειδιά
flow-injection analysis, nitrate determination, nitrite determination, spectrophotometry, system, waters, reduction, samples
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://A1996VA20700004
http://ac.els-cdn.com/0039914095018247/1-s2.0-0039914095018247-main.pdf?_tid=e35e6949ceac89b4b2c6d1af2ba7326d&acdnat=1333040996_699bc012e4c43585e6a06e61f3bee5e8
http://ac.els-cdn.com/0039914095018247/1-s2.0-0039914095018247-main.pdf?_tid=e35e6949ceac89b4b2c6d1af2ba7326d&acdnat=1333040996_699bc012e4c43585e6a06e61f3bee5e8
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας