Heterocyclic aromatic amines analysis

In a similar way, the use of formic acid/ammonium formate was shown to be superior to the use of acetic acid/ammonium acetate in the RP HPLC-ESI MS/MS analysis of a number of heterocyclic aromatic amines [7]. It is clear from numerous other examples in the literature that HPLC resolution and MS sensitivity can be dramatically influenced by the correct selection of mobile phases, organic modifiers, and ion-pairing additives. 

Heterocyclic aromatic amines (HAA) are carcinogenic compounds that may occur in food. They are probably formed during cooking processes by the pyrolysis of amino acids and proteins. Since the mid 1990s, LC-MS plays a role in the analysis and characterization of these HAA. Both ESI-MS and APCl-MS are applied. A recent special issne of Journal of Chromatography B [82] emphasizes the analytical challenges related to HAA. The stractnres of the most abundant HAA in cooked food are shown in Figure 14.10. 

Gangl et al. [74] reported a 100-fold improvement in the detection of in vivo formed DNA adducts derived from the food-derived 2-amino-3-methyhmidaz[4,5-/ quinohne (TQ, one of the heterocyclic aromatic amines, Ch. 14.5) by the apphcation of capillary LC in combination with micro-ESI-MS. As a result, the detection limit approaches 1 adduct in 10 nucleobases using 500 pg DNA. In a subsequent study [75], this technology was applied to the quantitative analysis of the IQ-dG adduct in rat liver samples in a dose-response study. The major adduct (C8-lQ-dG) could be detected at 17.5 fmol in 300 pg of liver DNA (corresponding to 2 adducts in 10 nucleobases). 

Richling E., Kleinschnitz, M. and Schreier P. Analysis of heterocyclic aromatic amines by high resolution gas chromatography-mass spectrometry a suitable technique for the routine control of food and process flavors. European Food Research and Technology. 210,68.1999. 

Many publications exist in the field of food analyses. Gerda Morlock described in 2004 the determination of heterocyclic aromatic amines after a 6-step AMD-separation. She used an HPTLC-MS online extractor, developed by Luftmarm [93a]. In 2004 a patent application was made for the mode of operation of this so-called ChromeXtrakt device [93b]. In her latest paper (2006), the quantification of isopropylthioxanthon (ITX) in food using HPTLC/FLD coupled with ESI-MS and DART-MS was reported. The prepared samples were separated on a HPTLC-plate and determined by a fluorescence detector (FLD). Positive results have been verified by ESI-MS (Electrospray-Ionisation-Mass-Spectrometry) and DART-MS (Direct Analysis in Real Trme-Mass-Spectrometry) [93c]. 

Turesky, R.J. and Vouros, P. (2004) Formation and analysis of heterocyclic aromatic amine-DNA adducts in vitro and in vivo. J. Chromatogr. E Analyt. Technol. Eiomed. Life Sci., 802,155-166. 

Riching, E., Herderich, M., and Schreier, P., High performance liquid chromatography-electrospray tandum mass spectrometry (HPLC-ESI-MS-MS) for the analysis of heterocyclic aromatic amines (HAA), Chromatographia, 42, 7-11, 1996. 

In contrast to heterocyclic aromatic amines, resveratrol (3,5,4Ctrihy-droxystilbene) and its isomers, natural phenofic compounds present in grape and wines, are beneficial to human health for many reasons primarily, there is a lower mortality from cardiovascular diseases observed in populations taking constantly a moderate amount of wine. SPE from red or white wine samples on LiChrolut EN and subsequent separation of the analytes by Hquid chromatography provides selective and fast analysis of resveratrol and its isomers [280]. 

CE procedures for the analysis of samples of biological origin have also been reported. Although the number of published methods remains small, a representative range of pesticides in various fruits, vegetables, and grains dyes (used as fruit fly toxicants) in coffee cherries and green roasted beans heterocyclic aromatic amines in fried beefsteak, meat... 

Toribio, E, Puignou, L., and Galceran, M.T. 1999. Evaluation of different clean-up procedures for the analysis of heterocyclic aromatic amines in a lyophilized meat extract. J. Chromatogr. A 836 223-233. 

Knize, M. G., Salmon, C. R, Mehta, S. S., and Felton, J. S. 1997b. Analysis of cooked muscle foods for heterocyclic aromatic amine carcinogens. Mutat. Res. 376 129-134. 

Richling, E., Decker, C., Haring, D., Herderich, M., and Schraier P. 1997. Analysis of heterocyclic aromatic amines in wine by high-performance hquid chromatography-electrospray tandem mass spectrometry. J. Chromatogr. A 791 71-77. 

Cardenes, L., Ayala, J. H., Afonso, A. M., and Gonzalez, V. 2004. Solid-phase microextraction coupled with high-performance hquid chromatography for the analysis of heterocyclic aromatic amines. J. Chromatogr. A 1030 87-93. 

Casal, S., Mendes, E., Fernandes, J. O., Ohveira, M. B. P. P., and Ferreira, M. A. 2004. Analysis of heterocyclic aromatic amines in foods by gas chromatography-mass spectrometry as their tert.-butyldimethylsilyl derivatives. J. Chromatogr. A 1040 105-114. 

Guy, P. A., Gremaud, E., Richoz, J., and Turesky, R. J. 2000. Quantitative analysis of mutagenic heterocyclic aromatic amines in cooked meat using liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry. J. Chromatogr. A 883 89-102. 

Heterocyclic aromatic amines, such as 2-amino-3-methylimidazo(4,5-f)quinoline, arise from amino acids, proteins, etc. during cooking. Billedeau et al used a short-chain alkyl-modified (SynChropak SCD-100) analytical column and ED (GCE, +0.6-0.9 V vs Ag/AgCl) in the analysis of these compounds. The eluent was acetonitrile-aq. ammonium acetate (50 mmol L pH 5.5-6.5) (25 + 75). No results of sample analyses were reported, however. 

LOQ) with MS/MS (20 pg) were found to be similar to HPLC/MS for the first time in the analysis of the heterocyclic aromatic amine harman (harmane) [14],... 

Felton, J.S., Pais, R, Salmon, C.R, Knize, M.G. Chemical analysis and significance of heterocyclic aromatic amines. Z. Lebensm. (Inters. Forsch. A 207, 434 (1998)... 

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. 

A -nitroso cpds, azo cpds, heterocyclics, aromatic nitro cpds, heterocyclic amines Environment analysis SPE Electrochemical methods [47]... 

Flavor isolation and analysis are made difficult also by the fact that flavors comprise a large number of chemical classes. If they were comprised of one or just a few classes of compounds, isolation methods could focus on molecular properties characteristic of a given class of compounds. Rather, the chemist must attempt to effectively extract and concentrate alcohols, aldehydes, acids, ketones, amines, carbonyls, heterocyclics, aromatics, gases, nonvolatiles (or nearly so), etc. 

The purpose of this analysis is to correlate some accessible quantum chemical results with physico-chemical properties of some aromatic compounds. The systems presented are hydrocarbons (aromatic aimu-lenes), amines, moleeules, ions, hydroxyarenes, and heterocycles with nitrogen, all of them selected according to their industrial significance. For example, by diazotization and coupling reactions the aromatic amines and phenols lead to azo dyes. The heterocyclic compounds take part in... 

Another pathway for the aromatization of the cr -adducts was found in the reactions of 3-pyrrolidino-l,2,4-triazine 4-oxide 81 with amines. Thus the treatment of 1,2,4-triazine 4-oxide 81 with ammonia leads to 5-amino-1,2,4-triazine 4-oxides 54—products of the telesubstitution reaction. In this case the cr -adduct 82 formed by the addition of ammonia at position 5 of the heterocycle undergoes a [l,5]sigmatropic shift resulting in 3,4-dihydro-1,2,4-triazine 83, which loses a molecule of pyrrolidine to yield the product 54. This mechanism was supported by the isolation of the key intermediates for the first time in such reactions—the products of the sigmatropic shift in the open-chain tautomeric form of tiiazahexa-triene 84. The structure of the latter was established by NMR spectroscopy and X-ray analysis. In spite of its open-chain character, 84 can be easily aromatized by refluxing in ethanol to form the same product 54 (99TL6099). 

Toxicity screening revealed cancerogenity of some primary aromatic and heterocyclic amines [309]. According to data obtained with rodents, the mutagenicity cannot be correlated with amine carcinogenity. Health damage analysis of workers in the rubber industry has been done very carefully [310], Primary amines may not be used as stabilizers. However, some commercial stabilizers... 

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