Critical Evaluation of the AOAC Method of Analysis for Nitrite in Meat

Nicholas, Rosemary A.; Fox, Jay B.

doi:10.1093/jaoac/56.4.922

Cited by 8 publications

(4 citation statements)

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“…The single-ion activity was calculated by the following equations22 logy, = IZ+/Z-llogy, logy-= Iz-/z+(logyk Macerated Chinese cabbage kept for 24 h at 25°C was treated according to the literature method. 23 The sample was analysed by both the electrode method and by spectrophotometry after being diluted 20-fold. The measurements of both the potentiometric selectivity coefficients and the concentration of NO2in Chinese cabbage were carried out in triplicate.…”

Section: Methodsmentioning

confidence: 99%

Nitrite-sensitive liquid membrane electrodes based on metalloporphyrin derivatives

Gao¹,

Gu²,

Yu³

et al. 1995

Analyst

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Section: Methodsmentioning

confidence: 99%

Nitrite-sensitive liquid membrane electrodes based on metalloporphyrin derivatives

Gao¹,

Gu²,

Yu³

et al. 1995

Analyst

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“…With fresh solutions, the cumulative coefficient of variation was ±2.5%. Standard dilution curves had coefficients of variation (at 10 µ N02") about 1%, and in a study of the AOAC method of nitrite analysis (9) we obtained an average coefficient of variation of 1.5%. In contrast, collaborative studies have shown inter-laboratory coefficients of variation of 9% (22) and 11% (13) for residual nitrite in cured meat products.…”

Section: Effect Of Varying the [Ns] And [Cr]mentioning

confidence: 79%

“…Ilosvay (6) first recommended the use of acetic acid which results in reaction solution pH values in the range of maximal conversion, pH 2.5-3.0 (7), for the sulfanilic acid/1naphthylamine reactions, but whether this is a universal range is not well established. The NS must be in at least 100-fold molar excess over nitrite for maximal pigment production (8,9). It has long been known that with a large excess of nitrite only yellow colors are produced (10), but the effect of large excesses of reagents has not been studied, nor have the optimal reagent concentrations been established.…”

mentioning

confidence: 99%

Kinetics and mechanisms of the Griess reaction

Fox¹

1979

Anal. Chem.

148

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The kind and position of substituents on the aniline and naphthylamine reagents used in the Griess method of nitrite analysis were assayed, and the factors that control the rate, amount, and stability of the pigment formed from the reaction were defined. This work has shown that the Hammett relationship may be used to determine in part the utility of the aniline derivatives under the unique conditions of nitrite analysis. However, specific reagent combinations result in poor pigment production because of multiple reactions, multiple products, incomplete conversion, and pigment instability. Impediments to complete conversion of nitrite to diazo pigment include multiple nitrous acid reactions with both the aniline and naphthylamine derivatives and instability of reaction intermediates. Other factors critical to pigment production, including pH, temperature, and concentration of reagents, both relative and absolute, were quantitated. Added reductants usually result in lessened pigment production, except with certain reagent combinations where the same or higher concentrations are produced. Criteria are given for establishing the utility of reagent combinations to be used for nitrite analysis.The formation of pigments from various nitrosatable compounds (principally aniline derivatives), nitrous acid, and various coupling reagents (principally naphthalene derivatives) was first described by Johann Peter Griess in 1864 ( I ) . This "Griess reaction", which forms the diazo pigments of major importance to the dye stuff industry, has been studied extensively. The reaction is of equal utility as a measure of nitrite, as Griess first demonstrated in 1879 ( 2 ) , and is extensively used for this purpose for analysis of nitrite in foodstuffs. There is a major difference in the way the reaction is carried out for the two purposes. The reaction proceeds in three steps: nitrosation, diazonium ion formation, and coupling. The first step is an acid reaction, the second an internal rearrangement, and the third a reaction that proceeds a t different rates depending on pH. In the production of dyestuffs, the diazonium salt is prepared from a nitrosated species (NS) in acid solution with excess nitrous acid, crystallized, and then reacted with the coupling reagent (CR) at the optimal pH, usually close to neutrality ( 3 ) . For nitrite analysis, the reaction is carried out a t a pH that is a compromise between the optimal p H values for the two pHdependent reactions, with all three reaction steps continuing simultaneously at limiting nitrite concentrations.For testing foods, especially meat products, nitrite analysis requires some sample preparation before the Griess reagents are added. In our laboratory, a study of a number of the sample preparation procedures in use globally ( 4 ) led us to conclude that the amount of nitrite measured depends not only on how much "free" or "bound" nitrite is originally present in cured meats, but also on how the sample preparation procedure affects other compounds that interfere in the color develop...

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“…Therefore, if the two reagents are added together this competing reaction can lead to the destruction of some nitrite and loss of color. For this reason, both the AOAC and the European Economic Community (EEC) methods call for the separate 24 8 N. P. SEN AND M. McPHERSON addition of the two color reagents (Fiddler 1977;Nicholas and Fox 1973). Sulfanilamide is added first, and after 5 min (when the diazotization reaction is complete) N-( l-naphthy1)ethylenediamine is added to form the pink azo dye.…”

Section: Introductionmentioning

confidence: 99%

Interference by Ascorbic Acid in the Determination of Nitrite by the Separate Color Reagent Addition Technique

Sen¹,

McPherson²

1978

Journal of Food Safety

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A study was carried out to determine if the presence of ascorbic acid interferes with the colorimetric determination of nitrite by the technique of separate addition of color reagents. It was shown that ascorbate can destroy some of the nitrite during pre‐incubation with sulfanilamide, one of the color reagents used to form the diazo compound. An alternative method of analysis is suggested in which ascorbic acid, in the concentration range normally found in foods and cured meat products, does not interfere.

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Critical Evaluation of the AOAC Method of Analysis for Nitrite in Meat

Cited by 8 publications

References 0 publications

Nitrite-sensitive liquid membrane electrodes based on metalloporphyrin derivatives

Nitrite-sensitive liquid membrane electrodes based on metalloporphyrin derivatives

Kinetics and mechanisms of the Griess reaction

Interference by Ascorbic Acid in the Determination of Nitrite by the Separate Color Reagent Addition Technique

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