Amino compounds liquid chromatographic

Wise SA, Chesisr SN, Hertz HS, Hilpert LR, and May WE (1977) A chemically bonded amino-silane stationary phase for the high-performance liquid chromatographic separation of polynuclear aromatic compounds. Anal Chem 49 2306-2310. 

As described in the section dealing with liquid chromatographic methods, the reaction of 0,0-di-substituted tartaric anhydrides with racemic amino alcohols in acidic solution leads exclusively to the corresponding diastereomeric monoesters, which are easily separated by reversed-phase HPLC. However, H- and sometimes 13C-NMR spectra of these compounds are in many cases also highly useful for determining the diastereomeric ratio and in many cases the absolute configuration. 

Often, treatment of samples with fluorescence labeling agent reacts with primary and secondary amines to give a fluorescent compound. This is especially important for detecting amino acids in protein hydrolyzates. Fluorescence detectors may also be integrated into a high performance liquid chromatographic (HPLC) system. 

Amadori compounds (N-substituted-l-amino-l-deoxy-2-ketoses) are potential precursors to the formation of many of these heterocyclic volatile products. The secondary nitrogen in most Amadori compounds is weakly basic and is therefore a likely site for rapid nitrosation reactions via normal reactions with nitrous acid, under mildly acidic conditions. However, purified Amadori compounds are usually obtained only after tedious isolation procedures are invoked to separate them from the complex mixtures of typical Maillard browning systems. Takeoka et al. ( 5) reported high performance liquid chromatographic (HPLC) procedures to separate Amadori compounds in highly purified form on a wide variety of columns, both of hydrophilic and hydrophobic nature. They were able to thus demonstrate that reaction products could be followed for kinetic measurements as well as to ensure purity of isolated products. 

Diastereomeric amides from camphor and camphor-related compounds have been used for the chiral resolution of amino acids by both gas and liquid chromatographic techniques. Nambara et al. [146] recommended the use of L-teresantalinyl chloride (56) to form the amides from alkylated amino acids for GC analyses. Although camphorsulphonamide p-nitrobenzyl esters have been used for LC separations [147,148], Aberhart el al. [149] found that these derivatives were difficult to prepare on a small scale, e.g. for enzyme assays. 

For the liquid chromatographic separation of amino acids and amino compounds, indirect separation techniques after precolumn labeling of the amino group are also widely used. By the precolumn derivatization approach, amino compounds are converted into structures that are suitable for separation and suitable for detection by various sensitive detectors. For the separation of the labeled amino compoimds, a wide variety of separation columns, including reversed-phase, can be used. Concerning detection, UV—Vis absorbance, fluorescence, and also MS (MS/MS) detectors are widely used, depending on the properties of the derivatization reagents. 

---