Service description
NOTE: This "Prestación" includes the determination of the Total Nitrogen and Phosphorus on marine freshwater samples using the Continuous Segmented Flux method in an automatized analyzer.
PRESTACIÓN: Total Nitrogen Determination
Method. Colorimetric determination by CFA system. It is based on the UV oxidation method proposed by Koroleff (1969, 1973) and adapted to the Continuous Flow Analyzer (CFA) by Seal Analytical (2008) combining a former digestion of the sample.
This method uses a 2-stage digestion at 110 ºC and high pressure (0.09 MPa). The first digestion is conducted with an alkaline (persulphate) reagent, followed by second digestion on acid. The digested sample is oxidized to nitrate which is subsequently reduced to nitrite using a cadmium-coper coil column. A final reaction with sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride (NEDD) produces a color proportional to the N concentration, which is read at 550 nm.
Reference: Methods of Seawater Analysis, K. Grasshoff, M. Ehrhardt, K. Kremling, second revised and extended edition, 1983.
Instrument. Autoanalyzer AA3 by Seal Analytical.
Analyses are run using the continuous flow analysis (CFA) technique, that separates a continuously flowing stream by means of air bubbles. The instrument was commercialized originally by Technicon Corporation, and nowadays by Seal Analytical. It incorporates a Julabo Digestor.
Quality control: Based on the Standard Methods and DIN / ISO Standards for automatic TN determinacions.
Method Seal Analytical: G-394-08 Rev.1
Occasionally International intercomparison (Quasimeme).
Detection limit of the method: 0,428 µM N-
Measuring lowest range: 0 to 71,0 µM N
Accuracy: 0,30 %
EPA procedure pt.136, app. B (by Seal Analytical manufacturer)
Options and prices chart
| Options |
Unit |
Public Sector |
Other customers |
| Análisis de Nitrógeno Total |
€ / muestra |
31.75 € |
37.79 € |