Marshall Method

For quantitative work, it is necessary to estimate the concentration of 5-amino-l-(P-D-ribofuranosyl)imidazole in aqueous solution. It seems that the only available method is the Bratton-Marshall assay, which was originally developed for the estimation of arylamines in biological fluids. The principle of the method is the spectrometric estimation of a salmon-pink colored dyestuff obtained by diazotation in situ, followed by coupling with /V-( 1 -naphthyl)ethyl-enediamine.65 The only remaining problem then is to know the molar extinction of this dye because pure samples of AIRs are not available. A value of 16800 at 520 nM was obtained for the dyes prepared from a model compound, 5-amino-l-cyclohexylimidazole-4-carboxylic acid (54), which is crystalline. A comparable molar extinction can be expected for the dye prepared from imidazole 55, if the carboxyl group does not exert too much influence on the chromophore. Actually, its influence is perceptible even with the naked eye, the dyestuff prepared from 53 having a somewhat different, wine-red color, with max>520 nM. The molar extinction for 55 is 17400 at 500 nM. When the decarboxylation of 54 was conducted under mild acidic conditions (pH 4.8, 50°C, 1 hour), estimation of 5-aminoimidazole 55 by the Bratton-Marshall method led to the conclusion that the reaction was almost quantitative.66 Similar conditions for the final decarboxylation were adopted in the preparation of samples of AIRs labeled with stable isotopes.58... 

Asphalt Institute recommended cold mix method Resistance to plastic flow of bituminous mixtures using Marshall Apparatus Immersion—Marshall method Immersion—Marshall method Superpave mix design... 

Modifications of the Bratton-Marshall method mentioned in Section IV.D.3.g can be used for sensitive spectrophotometric detection and determination of primary aromatic and heterocyclic amines. Thus, a simple spectrophotometric determination of the cardioprotective agent acadesine (142) was developed, to measure concentrations of the drug in plasma during intravenous infusion to patients undergoing coronary artery bypass graft surgery336. 

SAS mixes are optimized using a slightly modified Marshall Method (ASTM Method D 1559) and represent a series of trade-offs between stability and flow, air voids content and permeability and fatigue life [15]. The major departure from the Marshall Method is that only 2 hammer blows rather than the conventional 75 blows per face are used. The light compaction is used only to expel entrapped air and to achieve more uniform sample configurations without disturbing sulfur soldification within the aggregate voids. 

A. Neuberger and R.D. Marshall, Methods for the qualitative and quantitative analysis of the component sugars, in A. Gottschalk (Ed.), Glycoproteins Their Composition, Structure and Function, Elsevier, Amsterdam, 1966, pp. 190-234. 

SPE methods for organic environmental pollutants, including PAA (Table 1) and HA A (Table 2.B), coupled with electrophoresis end analysis were reviewed126. Analysis of PAA in environmental waters requires preconcentration and cleanup to remove interfering substances such as humic acids from the samples. This may be accomplished by several methods, for example (a) derivatization of the PAA by the Bratton-Marshall method followed by HPLC-UVD measuring at 460 nm (Section III.B.2) (b) flocculation of the water sample with Al3+ ions to selectively remove humic compounds before SPE (c) a... 

A colorimetric method for microdetermination of sulfonamides based on diazotization of the drug with sodium nitrite and hydrochloric acid has been reported (59). The diazonium salt is then coupled with 8-hydroxyquinoline in alkaline medium and the absorbance of the developed color measured at its maximum wavelength. A similar method involves diazotization and coupling of the sulfonamide with indole in alkaline solution to form an intense yellow azo dye which exhibits maximum absorption at 449 nm. Beer s law is obeyed over the concentration range 1-32 /ig/ml with a relative standard deviation of less than 2% (60). The reaction of sulfonamides with chloramine-T in sulfuric acid gives a yellow product which is suitable for the determination of sulfonamides in different formulations. It has an accuracy similar to that of the Bratton and Marshall method (61). 

Marshall method mix criteria Surface and other layers ... 

In this chapter, the design methodology called modified Marshall method for DGCAs, developed by the author, is going to be described in detail (Cabrera and Nikolaides 1988 Nikolaides 1983). 

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