Analytical conditions for the determination of 23 phenylthiocarbamyl amino acids and ethanolamine in musts and wines by high-performance liquid chromatography

Characterization and application of a new ultraviolet derivatization reagent for amino acids analysis in capillary electrophoresis

A new ultraviolet (UV) labeling reagent, p-acetamidobenzenesulfonyl fluoride (PAABS-F), was designed and synthesized to label and determine the amino acids by capillary electrophoresis (CE) with diode-array detector (DAD). PAABS-F is very stable and easy to synthesize. It reacted with primary or secondary amino acids very quickly under facile conditions to give corresponding derivatives in high yield with excellent sensitivity and stability. No by-products were observed in amino acid derivatives when stored at room temperature under natural daylight for at least 7 days. Both amino acids standard solution and real samples reacted with this new UV labeling reagent smoothly to form high UV-absorption derivatives. The labeled 20 standard amino acids were efficiently separated by CE and the mass detection limits (S/N=3) were ranged from 59.3 fmol for L-tryptophan to 1.70 pmol for L-histidine.

Role of chromatography in the analysis of sugars, carboxylic acids and amino acids in food

An overview is presented of chromatographic methods currently in use to determine sugars, carboxylic acids and amino acids in foods: high-performance liquid chromatography, gas chromatography and capillary electrophoresis. As a basis of selection the following approaches can be distinguished: quantitation of constituents of several food matrices, without derivatization and in the form of different derivatives, in the presence of the matrix, or subsequently to various work-up procedures.

Temperature, eluent flow-rate and column effects on the retention and quantitation properties of phenylthiocarbamyl derivatives of amino acids in reversed-phase high-performance liquid chromatography

The separation and identification possibilities of 27 PTC-amino acids (with particular attention to those present in apples in free forms), are reported on seven RP columns such as, Nucleosil, 3 and 5 microns: 150(+20 guard) x 4.0 mm; Gromsil 3 microns; 150(+10 guard) x 4.0 mm; Hypersil 5 microns: 130(+20 guard) x 4.0 mm, 150(+20 guard) x 4.0 mm and 200(+20 guard) x 4.0 mm, as well as, Hypersil 3 microns: 150(+20 guard) x 4.0 mm: a UV range photodiode array (PDA) detection was employed. Optimization studies carried out in model solutions, as a function of the temperature (30-55 degrees C) and flow-rate (0.8-2.5 ml/min) of eluents proved that optimum resolutions are associated with the highest flow-rate applicable, (remaining on the safe side with a column pressure of < 3500 p.s.i., 1 p.s.i. = 6894.76 Pa), in the temperature range of 30-50 degrees C. Twenty-seven amino acids, characteristic in apples in free forms, have been separated and determined on all seven columns, performing the same gradient program, (the main component asparagine, present in overwhelming excess, and the minor constituents glutamine, beta-alanine, gamma-aminobutyric acid, homoserine, homoarginine and 1-aminocyclopropane-1-carboxylic acid). Optimum conditions, at 2.1 ml/min, at 50 degrees C, with 40 min run time, including equilibration, have been obtained with the Hypersil, 150(+20 guard) x 4 mm column, performing elutions. Responses of the corresponding amino acids proved to be independent of the column used; reproducibility in the concentration range of 15-1500 pmol was < 4.0% R.S.D. (relative standard deviation). Detailed study of the PDA spectra revealed that in addition to the identification/peak purity possibilities further characteristics can be obtained taking advantage of the difference in maximum values and of those of their special ratio values, respectively. The utility of the protocol was shown in the quantitation of the free amino acid content of three apple varieties.