title: Study of sample preparation for quantitative analysis of amino acids in human sweat by liquid chromatography-tandem mass spectrometry.
abstract: The determination of physiological levels of amino acids is important to aid in the diagnosis and treatment of several diseases and nutritional status of individuals. Amino acids are frequently determined in biofluids such as blood (serum or plasma) and urine; however, there are less common biofluids with different concentration profiles of amino acids that could be of interest. One of these biofluids is sweat that can be obtained in a non-invasive manner and is characterized by low complex composition. The analysis of amino acids in human sweat requires the development of sample preparation strategies according to the sample matrix and small collected volume. The influence of sample preparation on the quantitative analysis of amino acids in sweat by LC-MS/MS has been assessed through a comparison between two strategies: dilution of sweat and centrifugal microsolid-phase extraction (c-μSPE). In both cases, several dilution factors were assayed for in-depth knowledge of the matrix effects, and the use of c-μSPE provided the best results in terms of accuracy. The behavior of the target analytes was a function of the dilution factor, thus providing a pattern for sample preparation that depended on the amino acid to be determined. The concentration of amino acids in sweat ranges between 6.20 ng mL(-1) (for homocysteine) and 259.77 µg mL(-1) (for serine) with precision, expressed as relative standard deviation, within 1.1-21.4%.
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, Córdoba, Spain; ceiA3, Agroalimentary Excellence Campus, University of Córdoba, Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain.
authors.forename: M M
authors.initials: MM
authors.lastname: Delgado-Povedano
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, Córdoba, Spain; ceiA3, Agroalimentary Excellence Campus, University of Córdoba, Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Calderón-Santiago
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, Córdoba, Spain; ceiA3, Agroalimentary Excellence Campus, University of Córdoba, Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain. Electronic address: q72prcaf@uco.es.
authors.forename: F
authors.initials: F
authors.lastname: Priego-Capote
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, Córdoba, Spain; ceiA3, Agroalimentary Excellence Campus, University of Córdoba, Córdoba, Spain; Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain. Electronic address: qa1lucam@uco.es.
authors.forename: M D
authors.initials: MD
authors.lastname: Luque de Castro
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000302:isolation & purification; D053000:Analytic Sample Preparation Methods / Q000379:methods*; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D052617:Solid Phase Microextraction; D013542:Sweat / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000596:Amino Acids
keywords: Amino acid; Biomarker; Liquid chromatography; Mass spectrometry; Sample preparation; Sweat