{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T03:54:00Z","timestamp":1777434840210,"version":"3.51.4"},"reference-count":15,"publisher":"SAGE Publications","issue":"2","license":[{"start":{"date-parts":[[2008,3,1]],"date-time":"2008-03-01T00:00:00Z","timestamp":1204329600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Ann Clin Biochem"],"published-print":{"date-parts":[[2008,3]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Urinary 5-hydroxyindole acetic acid (5-HIAA) is a useful marker for the turnover of tryptophan metabolites in the diagnosis and monitoring of carcinoid tumours and the carcinoid syndrome. We have developed a simple and cost-effective assay for urinary 5-HIAA using liquid chromatography\u2013tandem mass spectrometry (LC\u2013MS\/MS) incorporating an online sample clean-up process to replace a liquid chromatography electrochemical (LC-EC) technique.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Acidified urine was serially diluted in ammonium acetate buffer followed by ammonium acetate buffer enriched with 5-hydroxyindole-3-acetic-2,2-D2 acid internal standard. A 2.1 \u00d7 10 mm C18 column was used for primary online clean-up and eluted with 100% methanolic mobile phase onto a second dC18 Atlantis 2.1 \u00d7 20 mm column. Analytes were detected by mass spectrometry using transitions 192.1 &gt; 146.3 and 194.1 &gt; 148.0 for 5-HIAA and deuterated analyte, respectively.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Run time was 3 min with 5-HIAA eluting at 1.37 min. The inter and intra-assay imprecision and accuracies of the three levels of inhouse quality control (QC) (30, 300 and 600 \u03bcmol\/L) were acceptable with coefficient of variations (CVs) and deviation from target values &lt;12% ( n = 15). The average recovery of 5-HIAA spiked into urine was 93.7% with no ion suppression observed. The limit of detection was 2.8 and lower limit of quantification 4.0 \u03bcmol\/L. Passing\u2013Bablok regression of LC-EC with LC\u2013MS\/MS results showed good agreement between the methods, the relationship described as LC\u2013MS\/MS = 1.01(LC\u2013EC)\u20131.22. No systematic or proportional biases were observed over the working range of the method. The assay was linear to at least 2000 \u03bcmol\/L.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>We have developed a robust method offering a more than six-fold improvement in linearity compared to the existing LC\u2013EC method.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1258\/acb.2007.007067","type":"journal-article","created":{"date-parts":[[2008,3,2]],"date-time":"2008-03-02T19:31:35Z","timestamp":1204486295000},"page":"149-152","source":"Crossref","is-referenced-by-count":25,"title":["Online extraction of 5-hydroxyindole acetic acid from urine for analysis by liquid chromatography\u2013tandem mass spectrometry"],"prefix":"10.1177","volume":"45","author":[{"given":"Heather","family":"Perry","sequence":"first","affiliation":[{"name":"Department of Clinical Biochemistry, Wythenshawe Hospital, University Hospital of South Manchester, Manchester M23 9LT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brian","family":"Keevil","sequence":"additional","affiliation":[{"name":"Department of Clinical Biochemistry, Wythenshawe Hospital, University Hospital of South Manchester, Manchester M23 9LT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2008,3,1]]},"reference":[{"key":"bibr-ACB-07-067C1","first-page":"167","volume":"28","author":"Nuttall KL","year":"1998","journal-title":"Ann Clin Lab Sci"},{"key":"bibr-ACB-07-067C2","doi-asserted-by":"publisher","DOI":"10.1093\/clinchem\/26.7.910"},{"key":"bibr-ACB-07-067C3","doi-asserted-by":"publisher","DOI":"10.1016\/0024-3205(81)90144-2"},{"key":"bibr-ACB-07-067C4","doi-asserted-by":"publisher","DOI":"10.1016\/0024-3205(81)90138-7"},{"key":"bibr-ACB-07-067C5","doi-asserted-by":"publisher","DOI":"10.1177\/000456329403100302"},{"key":"bibr-ACB-07-067C6","doi-asserted-by":"publisher","DOI":"10.1258\/0004563053492810"},{"key":"bibr-ACB-07-067C7","doi-asserted-by":"publisher","DOI":"10.1016\/j.jchromb.2003.10.033"},{"key":"bibr-ACB-07-067C8","doi-asserted-by":"publisher","DOI":"10.1093\/clinchem\/48.2.323"},{"key":"bibr-ACB-07-067C9","doi-asserted-by":"publisher","DOI":"10.1093\/clinchem\/34.9.1897"},{"key":"bibr-ACB-07-067C10","doi-asserted-by":"publisher","DOI":"10.1038\/sj.bjp.0702399"},{"key":"bibr-ACB-07-067C11","doi-asserted-by":"publisher","DOI":"10.1016\/S0024-3205(98)00329-4"},{"key":"bibr-ACB-07-067C12","volume-title":"Guidance for Industry Bioanalytical Method Validation","author":"Health and Human Services, US Department of Food and Drug Administration, Center for Drug Evaluation and Research (CDER), Center for Veterinary Medicine (CVM)","year":"2001"},{"key":"bibr-ACB-07-067C13","doi-asserted-by":"publisher","DOI":"10.1093\/clinchem\/48.11.2049"},{"key":"bibr-ACB-07-067C14","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2005.050062"},{"key":"bibr-ACB-07-067C15","volume":"45","author":"Duxbury KJ","year":"2007","journal-title":"CCLM"}],"container-title":["Annals of Clinical Biochemistry: International Journal of Laboratory Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1258\/acb.2007.007067","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1258\/acb.2007.007067","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1258\/acb.2007.007067","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T11:54:55Z","timestamp":1777377295000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1258\/acb.2007.007067"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,3]]},"references-count":15,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2008,3]]}},"alternative-id":["10.1258\/acb.2007.007067"],"URL":"https:\/\/doi.org\/10.1258\/acb.2007.007067","relation":{},"ISSN":["0004-5632","1758-1001"],"issn-type":[{"value":"0004-5632","type":"print"},{"value":"1758-1001","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,3]]}}}