A New Method for the Determination of the Nitrogen Content of Tobacco. Application of the "Coleman" Nitrogen Analyser / Eine neue Methode zur Stickstoff-Bestimmung im Tabak: Die Anwendung des „Coleman“ Stickstoff-Analysators

1966 ◽  
Vol 3 (5) ◽  
Author(s):  
A.J. Artho ◽  
A. Cossy
Keyword(s):  
Nitrogen Content ◽  
Operating Conditions ◽  
New Method ◽  
Optimum Operating ◽  
Efficient Catalyst ◽  
Kjeldahl Method

AbstractThe present paper gives an account of tests carried out with the automatic ''Coleman'' apparatus to determine the nitrogen content of tobacco. Preliminary experiments made with different tobacco types led to the determination of optimum operating conditions which give exact and reproducible results. The values obtained by this procedure are the same as, or slightly superior to, those obtained by using the Kjeldahl method associated with the use of an efficient catalyst.

Determination of Nitrogen Content in Milk by the Kjeldahl Method Using Copper Sulfate: Interlaboratory Study

1988 ◽  
Vol 71 (5) ◽  
pp. 893-898 ◽  
Author(s):  
R Grappin ◽  
William Horwitz
Keyword(s):  
Quality Control ◽  
Nitrogen Content ◽  
Copper Sulfate ◽  
Interlaboratory Study ◽  
Internal Quality ◽  
Relative Standard ◽  
Nitrogen Concentrations ◽  
Kjeldahl Method ◽  
Repeatability And Reproducibility

Abstract Copper sulfate was substituted for mercury as the catalyst in the International Dairy Federation (IDF) Standard 20A:1986 method for the determination of nitrogen content in milk. The substitution was supported by results obtained in an interlaboratory study by 24 laboratories in 12 countries. Each laboratory analyzed 12 test samples of milk as blind duplicates in a double split level design with high, medium, and low nitrogen concentrations. The method protocol requires the concurrent analyses of an ammonium salt solution and a tryptophan solution as internal quality control standards with a minimum nitrogen recovery between 99 and 100% for the former and at least 98% for the latter. The repeatability and reproducibility relative standard deviations are 0.5 and 1%, respectively, for the range 0.35-0.70 g N/100 g. The performance of the laboratories that did not meet the required quality control specifications was clearly poorer than that of those that did meet the specifications.

scholarly journals A MODIFIED KJELDAHL METHOD FOR THE DETERMINATION OF THE NITROGEN CONTENT OF YEAST

1927 ◽  
Vol 2 (4) ◽  
pp. 455-460 ◽  
Author(s):  
Leo M. Christensen ◽  
Ellis I. Fulmer
Keyword(s):  
Nitrogen Content ◽  
Kjeldahl Method

scholarly journals Analytical application of acidic victoria blue 4R mixture with KBrO3 for the kinetic determination of traces of antimony(III) by spectrophotometry

2012 ◽  
Vol 31 (1) ◽  
pp. 29
Author(s):  
Violeta Mitić ◽  
Snežana Nikolić-Mandić ◽  
Vesna Stankov-Jovanović
Keyword(s):  
Reaction Rate ◽  
Kinetic Method ◽  
Operating Conditions ◽  
Rate Equations ◽  
Optimum Operating ◽  
Acid Media ◽  
Kinetic Determination ◽  
Hydrochloric Acid Media ◽  
Optimized Conditions

The present paper describes a simple, selective and sensitive kinetic method for the determination of trace amounts of Sb(III) in the presence of Sb(V) based on its inhibition effect on the redox reaction between bromate and Victoria blue 4R (V.B. 4-R) in hydrochloric acid media. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of V.B. 4-R at 596.3 nm. Optimum operating conditions regarding reagent concentrations were established. The optimized conditions yielded a theoretical detection limit of 1.30·10‒8 g cm–3 Sb(III) based on the 3S0 criterion. The method allows the determination of Sb(III) in the range of 5·10‒8 ‒ 1.1·10‒6 g cm–3. The effects of certain foreign ions the reaction rate were determined for an assessment of the selectivity of the method. The kinetic parameters of the reaction were reported, and the rate equations were suggested. The results were validated statistically and through recovery studies. The proposed method has been successfully applied to the determination of Sb(III) in various model and real samples.

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