Aliphatic amines derivatizing

Isocyanates and isothiocyanates react with primary and secondary amino compounds, and a variety of derivatization reagents have been reported. Both aliphatic and aromatic amines react with isocyanates to form N,N -disubstituted ureas (Figure 6.2). As an example, aliphatic amines derivatized with phenyl isothiocyanate (PITC) were nicely... 

Reports on the use of fluorescent derivatives abound (5). Some reagents have become widely used. The dansyl group is probably the most thoroughly studied. Dansyl chloride has been widely used as a fluorescent derivatizing reagent for HPLC (6,7). It reacts readily with primary and secondary amino groups (7) and with phenols (8), but forms derivatives of alcohols very slowly (9). The lower detection limit for dansyl derivatives of aliphatic amines is in the range of 300 femtomoles per injection. 

Note This reagent sequence can be employed to great advantage after the prechromato-graphic derivatization of primary and secondary amines with 2,4-dinitrofluoro-benzene this makes for virtually specific detection of aliphatic amines. 

Possanzini, M. and Di Palo, V., Improved HPLC determination of aliphatic amines in air by diffusion and derivatization techniques, Chromatographia, 29,151, 1990. 

Derivatized compounds with fluorophores (amino acids, steroids, aliphatic amines, carboxylic acids, catecholamines, etc.)... 

Advantages include in this CL system the reagent is regenerated and it can be recycled, and derivatization is not required for many classes of compounds. Many aliphatic amines such as alkylamines, amino acids, proteins, antibiotics such as erythromycin and clindamycin, and NADH, among others can par-... 

A determination of traces of low (Ci to C4) aliphatic amines in the atmosphere consists of passing air through an absorber containing phosphorous acid, derivatizing with m-toluyl chloride and end analysis by HPLC-UVD LOD 1-5 pmol of amine, corresponding to concentrations lower than 0.1 pg/m3 of air, in a 300 L sample232. 

Fig. 9.8 presents another, more complex type of phosphate prodrugs, namely (phosphoryloxy)methyl carbonates and carbamates (9-26, X = O or NH, resp.) [84], Here, the [(phosphoryloxy)methyl]carbonyl carrier appears quite versatile and of potential interest to prepare prodrugs of alcohols, phenols, and amines. The cascade of reactions leading from prodrug to drug as shown in Fig. 9.8 involves three steps, namely ester hydrolysis, release of formaldehyde, and a final step of carbonate hydrolysis (X = O) or A-decar-boxylation (X = NH). Three model compounds, a secondary alcohol, a primary aliphatic amine, and a primary aromatic amine, were derivatized with the carrier moiety and examined for their rates of breakdown [84], The alcohol, indan-2-ol, yielded a carrier-linked derivative that proved relatively... 

N-McLhylmorpholine-N-oxidc monohydrate, a tertiary, aliphatic amine N-oxide, is able to dissolve cellulose directly, i.e. without chemical derivatization, which is used on an industrial scale as the basis of the Lyocell process [ 1, 2], This technology only requires a comparatively low number of process steps compared for instance to traditional viscose production. Cellulose material - mainly fibers - are directly obtained from the cellulose solution in NMMO no chemical derivatization, such as alkalization and xanthation for rayon fibers, is required [3]. The main advantage of the Lyocell process lies in its environmental compatibility very few process chemicals are applied, and in the idealized case NMMO and water are completely recycled, which is also an important economic factor. Even in industrial production systems NMMO recovery is greater than 99%. Thus, compared with cotton and viscose the Lyocell process pertains a significantly lower specific environmental challenge [4]. Today, Lyocell fibers are produced on an industrial scale, and other cellulosic products, such as films, beads, membranes and filaments, are also currently being developed or are already produced commercially. 

A gas-phase derivatization procedure was employed for direct amidization of oxidized SWCNTs with simple aliphatic amines. In some cases a minor amount... 

Under proper conditions DHA reacts with amines to form SchiflF bases. Dahn and Moll describe this reaction between o-phenylene-diamine and DHA as well as with other 2,3-diketobutyrolactones (25). With aliphatic amines and amino acids, the Schiff base is not favored in aqueous solution. The extent of the reversible formation of Schiff bases of DHA has not been extensively studied, and clearly needs more attention. DHA in biological fluids is probably in reversible equilibrium with amino groups of amino acids, proteins, and other amines. However, the extent of any such conjugation is unknown. If such bases are formed, they probably involve derivatization of the 2-position of DHA. 

The diazonium salt is readily prepared from the aminophenyl group, but does not result from treatment of an aliphatic amine (such as the APTES-derivatized surface) with nitrous acid. The activated surface is now ready for enzyme coupling, since diazonium salts are very reactive toward protein tyrosine residues (Eq. 4.4) ... 

A derivatization technique must be used if ammonium is to be determined in this sample. The high concentration of alkali and alkaline-earth metals does not allow a conductometric detection of this ion. To detect ammonium selectively, the derivatization technique using o-phthaldialdehyde with subsequent fluorescence detection is suited that has been described repeatedly. This is illustrated in Fig. 8-23 with the chromatogram of a sample that was diluted 1 5 in which a primary aliphatic amine is detected as well as ammonium using this detection method. 

Wald J, Alberto R, Ortner K, Candreia L (2001) Aqueous one-pot synthesis of derivatized cyclo-pentadienyl-tricarbonyl complexes of Tc-99m with an in situ CO source application to a serotonergic receptor ligand. Angew Chem Int Edit 40 3062-3066 Wei LFi, Babich J, Zubieta J (2005) Bifunctional chelates with mixed aromatic and aliphatic amine donors for labeling of biomolecules with the [Tc(CO)3] and [Re(CO)3] -cores. Inorg Chim Acta 358 3691-3700... 

Terashi et al." reported the determination of primary and secondary aliphatic amines in the environment by gas chromatography-mass spectrometry. Many derivatization... 

A simultaneous way of determining ammonia including aliphatic amines, aromatic amines, and phenols in environmental samples by GC-MS method using a single derivatization reagent has been reported recently by Mishra et al. The method consisted in precolumn formation of benzoate esters and benzamides under the conditions of the Schotten-Baumann procedure with benzoyl chloride and SPE of the derivatives. The limit of detection of ammonia was 20 /rg/l when 80 ml of sample was preconcentrated, after derivatization, on a styrene divinyl benzene copolymer sorbent. 

Various derivatization reagents have been developed and used as labeling reagents for traces of primary and secondary aliphatic amines in HPLC, including OPA, 3,5-dinitrobenzoyl chloride,... 

Wang, H., Li, J., Liu, X., and Zhang, H.-S., A -hydroxysuccinimidyl fluorescein-O-acetate as a highly fluorescent derivatizing reagent for aliphatic amines in hquid chromatography. Anal. Chim. Acta, 423, 77-83, 2000. 

Andres, J. V., Ealca, P. C., and Hernandez, R. H., Liquid chromatographic determination of aliphatic amines in water using solid support assisted derivatization with 9-fluorenylmethyl chloroformate, Chromatographia, 55, 129-135, 2002. 

Sahasrabuddhey, B., Jain, A., and Verma, K. K., Determination of ammonia and aliphatic amines in environmental aqueous samples utilizing pre-column derivatization to their phenylthioureas and high performance liquid chromatography, Ana/yrf, 124, 1017-1021, 1999. 

Brumley, W. and Kelliher, V., Determination of aliphatic amines in water using derivatization with fluorescein isothiocyanate and capillary electrophoresis/laser-induced fluorescence detection, J. Liq. Chromatogr., 20, 2193-2205, 1997. 

Use of selective derivatization reactions prior to the separation allows the introduction of functional groups which can be detected with high selectivity. In some cases derivatization can be carried out on-line before (pre-column) or after the separation column (post-column) [23]. Use of fluorescent reagents which react selectively with, eg, aliphatic amines is an example of pre-column derivatization. 

The analysis of small aliphatic amines by electromigration methods faces a few challenges. Although readily protonated at low pH electrolytes, the lack of chromophore precludes direct UV-detection in both CZE and EKC mode unless derivatizing schemes are devised or alternative detectors are selected. A further complication of the EKC mode derives from the hydrophilicity and polar characteristic of aliphatic amines, which usually impair strong interaction with commonly used micellized surfactants, demanding alternative secondary phases or more elaborate electrolytes. 

Indirect UV-detection is a feasible option and particularly interesting for the CZE determination of primary to quarternary amines without derivatization. Imidazole, Af-ethylbenzylamine, and ben-zyltriethylammonium chloride have been proposed as electrolyte chromophoric constituents. The indirect UV-detection of aliphatic amines in ambient air has been performed by CZE in imidazole-based buffer modified by ethanol and EDTA. By replacing imidazole with ammonium, the electrolyte became applicable to MS detection (these details and other CZE methodologies are reported in Table 31.4). 

EKC separations of aliphatic amines include electrolyte systems composed of several surfactants (SDS, cholate, Brij 35 ) modified by certain additives (urea, neutral CDs, organic solvents ), mixed CDs, and more unusual secondary phases [resorcarene-octacarboxylic acid, calixarene," poly(sodium 4-styrenesulfonate), PSSS ]. Derivatization is performed when UV (o-phthaldialdehyde, OPA, as derivatizing agents) or LIF detection [3-(2-furoyl)quinoline-2-carboxaldehyde, 5-(4,6-dichloro-s-triazin-2-ylamino)fluorescein (DTAF) as labeling agents] is designed. 

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