Analysis of aromatic amines

In the context of the stability of the nitrosoamine intermediate in the diazotization of heteroaromatic amines relative to that in the case of aromatic amines, the reversibility of diazotization has to be considered. To the best of our knowledge the reverse reaction of a diazotization of an aromatic amine has never been observed in acidic solutions. This fact is the basis of the well-known method for the quantitative analysis of aromatic amines by titration with a calibrated solution of sodium nitrite (see Sec. 3.3). With heteroaromatic amines, however, it has been reported several times that, when using amine and sodium nitrite in the stoichiometric ratio 1 1, after completion of the reaction nitrous acid can still be detected with Kl-starch paper,... 

A 12-port valve was used for the periodic sampling of the first column onto multiple second-dimension columns for the 2DLC analysis of aromatic amines and other species (Venkatramani and Zelechonok, 2003). The utility of the 12-port valve is that two columns can be utilized in the second dimension and flow is kept constant through both columns. This configuration requires three sample loops for implementation. The output of the second-dimension columns are connected so that both columns continuously feed the detector. 

The use of a basic glass capillary column in the analysis of aromatic amines has several advantages ... 

Methods for the analysis of aromatic amines in synthetic azo dyes and in food and beverages colored with these dyes have been developed. High-performance LC or GC methods are generally employed, often with the help of derivatization reaction and fluorimetric detection, with HPLC generally regarded as the best technique for the determination of aromatic amines. 

Zhou, Q., G. Jiang, J. Liu, and Y. Cai. 2004. Combination of microporous membrane liquid-liquid extraction and capillary electrophoresis for the analysis of aromatic amines in water samples. Anal. Chim. Acta 509 55-62. 

Analysis of Aromatic Amines by High Performance Liquid Chromatography... 

Zhao L, Zhu L, and Lee HK. Analysis of aromatic amines in water samples hy means of hquid-hquid-hquid microextraction with hoUow-fihers and high performance liquid chromatography. J. Chromatogr. A 2002 963 239-248. 

Chemical studies on tobacco smoke LXIV. On the analysis of aromatic amines in cigarette smoke. 

Smith, C. J., Dooly, G. L., and Moldoveanu, S. C., New technique using solid-phase extraction for the analysis of aromatic amines in mainstream cigarette smoke, J. Chromatogr., 991, 99-107,... 

Stahhert, R., Schafer, K. H., Biefel, Ch., and Rustemeier, K., Analysis of aromatic amines in cigarette smoke. Rapid Commun. Mass Spectrom., 17, 2125-2132, 2003. 

Chemists Research Conference, Program Booklet and Abstracts, Vol. 31, Paper No. 44, 1977, p. 23 Patrianakos, C.P. and D. Hoffmann Chemical studies on tobacco smoke. LXIV On the analysis of aromatic amines in cigarette smoke J. Anal. Toxicol. 3 (1979) 150-154. 

Shin, D., Tryk, D. A., Fujishima, A., Muck Jr., A., Chen, G, and Wang, J., Microchip capillary electrophoresis with a boron-doped diamond electrochemical detector for analysis of aromatic amines,... 

Despite the high sensitivity of amperometric detection, its use in environmental applications has not been exploited accordingly. Nevertheless, a few examples include the MEKC analysis of herbicides in tap water and the CZE and MEKC analysis of aromatic amines in contaminated water samples. ... 

CZE analysis of aromatic amines include the use of simple buffers at varying pH (acetate, phosphate, and borate ) with direct UV, electrochemical, or fluorescence detection. 

Conventional cation exchangers can also be used for the analysis of aromatic amines, in which hydrophobic interactions dominate the separation mechanism. As with the separation of quaternary ammonium compounds, the elution of anilines shown in Figure 4.86 is also carried out with a solvent gradient at constant acid concentration. Anilines are detected photometrically at 210 nm. A slight elevation of the column temperature - as already discussed for the analysis of aliphatic diamines - has a positive effect on the peak form of the late-eluting components. 

Separation of aromatic amines by HPLC is presently a common practice for the analysis of these substances in water, avoiding the need for pre-derivatisation and the risk of thermal degradation in Gas Chromatography. HPLC is often used for direct analysis of aromatic amines. As example, Melo et al. (2008) have analysed by HPLC the presence of heterocyclic aromatic amines in Portuguese bovine meat dishes prepared by three different cooking methods. Other examples are given in Table 7.2. 

The improved analytical performance of a diamond electrode for CE ED analysis has broadened the range of target chemicals to include many biologically and environmentally important compounds that exhibit high oxidation potentials and serious fouling problems. The CE-ED analysis of aromatic amines [13]... 

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