{"id":162,"date":"2013-09-12T10:55:13","date_gmt":"2013-09-12T09:55:13","guid":{"rendered":"http:\/\/wdb.ugr.es\/~fqm302\/blog\/?p=162"},"modified":"2013-09-12T10:55:13","modified_gmt":"2013-09-12T09:55:13","slug":"micellar-electrokinetic-chromatography-electrospray-ionization-mass-spectrometry-employing-a-volatile-surfactant-for-the-analysis-of-amino-acids-in-human-urine","status":"publish","type":"post","link":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/?p=162","title":{"rendered":"Micellar electrokinetic chromatography\u2013electrospray ionization mass spectrometry employing a volatile surfactant for the analysis of amino acids in human urine"},"content":{"rendered":"<p>A new MEKC-ESI-MS method for the analysis of amino acids (AAs) in human  urine was developed employing ammonium perfluorooctanoate (APFO) as  volatile surfactant. The influence of APFO on the MS signal of AAs was  evaluated by infusion experiments, which showed that APFO hardly affects  analyte responses and presents significantly less ion suppression than  equal concentrations of ammonium acetate. In order to obtain efficient  separation of AAs, MEKC parameters such as the pH and APFO concentration  of the BGE, were optimized. Optimum AA resolution, including baseline  separation of leucine and isoleucine, was obtained using 150 mM APFO (pH  9.0) as BGE, representing a considerable selectivity improvement over  CE using 50 mM ammonium acetate (pH 9.0). Optimization of CE-MS  parameters, such as sheath liquid composition and flow rate, and ESI and  MS settings, led to LODs ranging from 9 to 26 ng\/mL for the 20 tested  AAs, which is highly favorable for an MEKC-MS method. Good linearity (<em>r<\/em><sup>2<\/sup> &gt; 0.99) and repeatability were obtained for all AAs tested with RSD  values of 3.0\u20136.7% for peak area and &lt;1.5% for migration time. The  applicability of the MEKC-MS method was demonstrated by the quantitative  determination of AAs in urine employing only a 1:1 dilution with BGE as  sample pretreatment. All AAs could selectively be detected and  quantified obtaining relevant concentration values for normal human  urine.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A new MEKC-ESI-MS method for the analysis of amino acids (AAs) in human urine was developed employing ammonium perfluorooctanoate (APFO) as volatile surfactant. The influence of APFO on the MS signal of AAs was evaluated by infusion experiments, which showed &hellip; <a href=\"https:\/\/wpd.ugr.es\/~fqm302\/blog\/?p=162\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,25,26,60],"tags":[90,101],"class_list":["post-162","post","type-post","status-publish","format-standard","hentry","category-amino-acids","category-mekc","category-mass-spectrometry","category-urine","tag-ce","tag-ms"],"_links":{"self":[{"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=\/wp\/v2\/posts\/162","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=162"}],"version-history":[{"count":0,"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=\/wp\/v2\/posts\/162\/revisions"}],"wp:attachment":[{"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=162"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=162"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpd.ugr.es\/~fqm302\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=162"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}