Determination of amino acids by high-performance liquid chromatography with ultraviolet detection

Metoda tekućinske kromatografije uz detekciju ultraljubičastim zračenjem (HPLC-UV) korištena je za određivanje odabranih aminokiselina u vodenim uzorcima uz derivatizacijski reagens 9-fluorenilmetil-klorformijat (Fmoc-Cl). Sintetizirani su Fmoc-aminokiselinski derivati i okarakterizirani spektroskopskim metodama te korišteni kao analitički standardi. Razvojem metode optimirani su kromatografski uvjeti kojim je postignuta dobra rezolucija i razdvajanje odabranih Fmoc-aminokiselinskih derivata i nusprodukata koji nastaju u derivatizacijskoj reakciji. Istraženi su i optimirani reakcijski uvjeti za osiguravanje ekvimolarnosti derivatizacijske reakcije s obzirom na poznati dodatak pojedine aminokiseline. Kromatografskom HPLC-UV metodom određen je maseni udio glutaminske kiseline (1,2 -13,4 %) u odabranim dodatcima jelima.Liquid chromatography with ultraviolet detection (HPLC-UV) was used for the determination of selected amino acids in aqueous samples using 9-fluorenylmethyl chloroformate (Fmoc-Cl) as a derivatization reagent. Fmoc-amino acid derivatives were synthesized and characterized by spectroscopic methods. Formed products were used as analytical standards. Through the development of the HPLC method, the chromatographic conditions were optimized, which led to a fine resolution and separation of the selected Fmoc-amino acid derivatives and by-products formed in the derivatization reaction. The reaction conditions for ensuring the equimolarity of the derivatization reaction were investigated and with respect to the known addition of each amino acid. By the obtained HPLC-UV method, the mass content of glutamic acid (1,2 -13,4%) in some food additives was determined