title: Automated immunoassays for 25-hydroxyvitamin D (25-OHD): do plasticisers interfere?
abstract: The international quality assessment scheme for vitamin D metabolites (DEQAS) was established in 1989. The scheme involves the quarterly distribution of 5 serum samples prepared from blood collected in plain plastic bags. Following transfer of the donors to a clinic using different bags, sera were found to contain a contaminant that interfered in both the local LC-MS/MS assay and the NIST reference measurement procedure for 25-OHD. It seemed likely that the contaminant was a substance, possibly a plasticiser, leached from the plastic bag. It was subsequently suggested that the unidentified contaminant might also cause interference in certain automated non-extraction assays for 25-OHD. This was investigated in 3 automated immunoassays by comparing serum 25-OHD results from blood collected simultaneously into plain glass tubes and plastic bags. There was no significant difference in results, indicating that the leached substance had no effect on any of the 3 immunoassays examined.
authors.affiliation: Department of Clinical Biochemistry, Department Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK. Electronic address: b.carter1@which.net.
authors.forename: G D
authors.initials: GD
authors.lastname: Carter
authors.affiliation: Department of Clinical Biochemistry, Department Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
authors.forename: J
authors.initials: J
authors.lastname: Jones
authors.affiliation: Department of Clinical Biochemistry, Department Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
authors.forename: M
authors.initials: M
authors.lastname: Ketheeswaran
authors.affiliation: Department of Clinical Biochemistry, Department Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
authors.forename: J
authors.initials: J
authors.lastname: Shannon
authors.affiliation: Department of Clinical Biochemistry, Department Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
authors.forename: B
authors.initials: B
authors.lastname: Singh
authors.affiliation: Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, William Harvey Hospital, Ashford, Kent TN24 0LZ, UK.
authors.forename: E
authors.initials: E
authors.lastname: Kearney
authors.affiliation: Department of Clinical Biochemistry, Central Manchester NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Institute of Human Development, University of Manchester, Manchester M13 9PT, UK.
authors.forename: J L
authors.initials: JL
authors.lastname: Berry
mesh_terms: D001331:Automation; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D010968:Plasticizers / Q000032:analysis*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000276:immunology; D014815:Vitamins / Q000097:blood* / Q000276:immunology*
chemical_list: D010968:Plasticizers; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-Hydroxyvitamin D; DEQAS; Immunoassays; Plasticisers