2026-04-17T07:00:32Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/195542024-06-18T13:56:23Zcom_2072_452955com_2072_2054col_2072_453073

00925njm 22002777a 4500 dc Castellanos, María del Mar author Van Eendenburg, Cecile author Gubern Mérida, M. Carme author Sánchez Navarro, Juan Manuel author 2016-09-01 Conventional C18 silica columns have proven to be useful for the analysis of amino acids (AA) from protein hydrolysates but undesirable peak overlapping is usually found when analyzing body fluids given that a large number of AAs are present in the samples. As an alternative to silica packings, an ethyl-bridged packing for reversed-phase liquid chromatography of derivatized AAs with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) has been evaluated. The new packing material improves theseparation efficiency allowing better separations when analyzing biological fluids. Moreover, this packing has advantages for routine AA analysis, such as a decrease in the total running time and an increase in the life-time of the columns. The pH of the mobile phase has a significant effect on the elution behavior of the AQC hydrolysis product (AMQ) and on the AA derivatives. It is not possible to elute AMQ before detecting the first AA derivative, which requires an accurate adjustment of the pH in the range of 5.30-5.35 to obtain good separation and resolution for the most polar compounds. Under the conditions proposed, it is possible to separate all AAs except the Gly-Gln pair, which is not a problem when hydrolyzed samples are analyzed. The AMQ-Ser pair requires either the use of a different mobile phase pH for its baseline separation or the use of fluorescence detection. Two different procedures for protein removal from plasma samples have been evaluated, solvent precipitation and ultrafiltration (UF) and it has been found that UF gives better results as no significant losses of AAs were observed. The validation of the proposed method with UV detection gives method detection limits in the range of 8-12 microM, with repeatability values < 8% (n = 6) and inter-day precision in plasma samples ranging from 4 to 13% (n = 4) This study has been partially supported by the Red INVICTUS (RD12/0014/0001), integrated in the Plan Estatal de I+D+i and co-financed by the Subdirección General de Evaluación y Fomento de la Investigación of the Instituto de Salud Carlos III and by the European Regional Development Fund (ERDF), and the University of Girona (MPCUdG2016/100) http://hdl.handle.net/10256/19554 Aminoàcids Ultrafiltració Cromatografia de líquids Amino acids Ultrafiltration Liquid chromatography Cerebral ischemia --Treatment Thrombolytic therapy Ethyl-bridged hybrid column as an efficient alternative for HPLC analysis of plasma amino acids by pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate