title: Capillary electrophoresis method with UV-detection for analysis of free amino acids concentrations in food.
abstract: Simple and inexpensive capillary electrophoresis with UV-detection method (CE-UV) was optimized and validated for determination of six amino acids namely (alanine, asparagine, glutamine, proline, serine and valine) for Sudanese food. Amino acids in the samples were derivatized with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) prior to CE-UV analysis. Labeling reaction conditions (100mM borate buffer at pH 8.5, labeling reaction time 60min, temperature 70°C and NBD-Cl concentration 40mM) were systematically investigated. The optimal conditions for the separation were 100mM borate buffer at pH 9.7 and detected at 475nm. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) (RSD%) and accuracy (recovery). Good linearity was achieved for all amino acids (r(2)>0.9981) in the concentration range of 2.5-40mg/L. The LODs in the range of 0.32-0.56mg/L were obtained. Recoveries of amino acids ranging from 85% to 108%, (n=3) were obtained. The validated method was successfully applied for the determination of amino acids for Sudanese food samples.
authors: Applied Analytical Chemistry, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany; Department of Chemistry, Faculty of Science, University of Khartoum, Khartoum 11115, Sudan; Central Laboratory, Ministry of Sciences & Technology, P. O. Box Office 7099, Khartoum, Sudan.
authors: Mei Musa Ali
authors: MMA
authors: Omar
authors: Department of Chemistry, Faculty of Science, University of Khartoum, Khartoum 11115, Sudan. Electronic address: aaelbashir@uofk.edu.
authors: Abdalla Ahmed
authors: AA
authors: Elbashir
authors: Applied Analytical Chemistry, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany. Electronic address: oliver.schmitz@uni-due.de.
authors: Oliver J
authors: OJ
authors: Schmitz
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005502:Food; D005504:Food Analysis / Q000379:methods*; D057230:Limit of Detection; D013696:Temperature
chemical_list: D000596:Amino Acids
keywords: 4-Chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl); Amino acids; Capillary electrophoresis; Food