Flow injection determination of readily assimilable nitrogen compounds during vinification

Gonzalez-Rodriguez, Jose and Luque de Castro, Maria Dolores and Perez Juan, Pedro (2002) Flow injection determination of readily assimilable nitrogen compounds during vinification. The Analyst, 127 (3). pp. 420-423. ISSN 0003-2654

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Flow injection determination of readily assimilable nitrogen compounds during vinification
A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements.
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Full text URL: http://dx.doi.org/10.1039/b110686b

Abstract

A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements.

Item Type:Article
Additional Information:A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements.
Keywords:wine, must, flow injection, spectrophotometry, nitrogen, ammonium, amines, chemometry, method validation, automation, analytical chemistry, food chemistry
Subjects:F Physical Sciences > F110 Applied Chemistry
F Physical Sciences > F111 Industrial Chemistry
F Physical Sciences > F190 Chemistry not elsewhere classified
F Physical Sciences > F100 Chemistry
F Physical Sciences > F180 Analytical Chemistry
Divisions:College of Science > School of Life Sciences
ID Code:2116
Deposited By: Jose Gonzalez-Rodriguez
Deposited On:08 Jan 2010 10:14
Last Modified:13 Mar 2013 08:34

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