Determination of Nitrate Based on the Least Area Value Model in the Ocean

Abstract:

In situ monitoring of nitrate in respect of improvement of accuracy becomes more and more important. The direct spectrophotometer analysis of aqueous nitrates is a simple analytic procedure but prone to interferences. In order to solve this problem, the Least Area Value (LAV) Model for in situ determining nitrate in the ocean is reported. The absorbance response of the LAV model varies linearly with concentrations.Calculations of it are in excellent much higher accuracy than conventional measurement models.And more, it solves the problem without the need to measure the dark current first. This eliminated errors due to changes in the dark current during periods shortly after the instrument was turned on. The noise is nearly random and significant reductions in the detection limit are possible by averaging multiple observations in this model. The measurements were directly taken after dilution of the samples between 0.1μmol/l and 400μmol/l.The model was checked on and applied to real samples .The results show that this approach is suitable for routine field measurements of nitrate, which has achieved the precision of 99% and the stability of 99.5%. The model is simple, rugged. The precision, accuracy and stability of the concentrations are sufficiently used to support for many studies.

• Periodical: Advanced Materials Research (Volumes 726-731)
• Pages: 66-73
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.726-731.66
• Online since: August 2013
• Authors: Ling Ling Shen, Shu Ming Ye, Hang Chen
• Keywords: Analysis Techniques, LAV, Nitrate, Ocean, Spectrophotometer

References

[1] Di Noto,V.,Mecozzi, M., 1997. Determination of seawater salinity by ultraviolet spectroscopic measurements. Applied Spectroscopy 51, 1294–1302.

DOI: 10.1366/0003702971942295

[2] Green S.A. Blough N.V.,1994.Optical absorption and fluorescence properties of chromophoric dissolved organic matter in natural waters. Limnology and Oceanography 39, 1903–1916.

DOI: 10.4319/lo.1994.39.8.1903

[3] Michael Raessler, Ines Hilke. Ion-Chromatographic Determination of Low Concentrationsof Nitrate in Solutions of High Salinity. MicrochimActa; 2006, 27–29.

DOI: 10.1007/s00604-006-0495-z

[4] Mikael Karlsson, Bo Karlberg, Ralf J.O. Olsson. Determination of nitrate in municipal waste water by UV spectroscopy. Analitica Chimica Acta; 1995, pp.107-113.

DOI: 10.1016/0003-2670(95)00179-4

[5] Holm, T.R., Kelley, W.H., Sievers, L.F., Webb, D.L., 1997. A comparison of ultraviolet spectroscopy with other methods for the determination of nitrate in water. 38–45.

[6] H.P. Hansen, F. Koroleff, in: K. Grasshoff, K. Kremling, M. Ehrhardt (Editors), Methods of seawater analysis, Wiley-VCH, Weinheim, Germany, 1999, p.159–228.

[7] M.N. Abbas, G.A. Mostafa. Determination of traces of nitrate and nitrate in water by solid phase spectrophotometry, Analytica Chimica Acta; 2000, 185-192.

DOI: 10.1016/s0003-2670(00)00736-4

[8] K.S. Johnson, L.J. Coletti, Deep-Sea Res. I 49 (2002) 1291.