title: Long-Term stability of 6-hydroxymelatonin sulfate in 24-h urine samples stored at -20 degrees C.
abstract: The purpose of the present feasibility study was to determine whether the concentration of 6-hydroxymelatonin sulfate (6-OHMS) remains stable in urine samples stored over at least 15 yr. To test this, 117 twenty-four-hour urine samples were analyzed, which were obtained from healthy children ages 8 to 9 yr within the periods of 1985-1987,1991-1993, and 1997-1999. 6-OHMS concentrations were determined by enzyme-linked immunosorbent assay. The statistical analyses clearly indicate that the concentration of 6-OHMS remains stable for at least 15 yr if the urine is stored at -20 degrees C.
authors.affiliation: Institute for Occupational Physiology at the University of Dortmund, Federal Republic of Germany. griefahn@arb-phys.uni-dortmund.de
authors.forename: B
authors.initials: B
authors.lastname: Griefahn
authors.forename: T
authors.initials: T
authors.lastname: Remer
authors.forename: M
authors.initials: M
authors.lastname: Blaszkewicz
authors.forename: P
authors.initials: P
authors.lastname: Bröde
mesh_terms: D002648:Child; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005615:Freezing; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine*; D013048:Specimen Handling; D013997:Time Factors
chemical_list: D008550:Melatonin; C012365:6-hydroxymelatonin