title: Quantification of multiple elements in dried blood spot samples.
abstract: BACKGROUND
  Dried blood spots (DBS) is a unique matrix that offers advantages compared to conventional blood collection making it increasingly popular in large population studies. We here describe development and validation of a method to determine multiple elements in DBS.
  
  
  METHODS
  Elements were extracted from punches and analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The method was evaluated with quality controls with defined element concentration and blood spiked with elements to assess accuracy and imprecision. DBS element concentrations were compared with concentrations in venous blood. Samples with different hematocrit were spotted onto filter paper to assess hematocrit effect.
  
  
  RESULTS
  The established method was precise and accurate for measurement of most elements in DBS. There was a significant but relatively weak correlation between measurement of the elements Mg, K, Fe, Cu, Zn, As and Se in DBS and venous whole blood. Hematocrit influenced the DBS element measurement, especially for K, Fe and Zn.
  
  
  CONCLUSIONS
  Trace elements can be measured with high accuracy and low imprecision in DBS, but contribution of signal from the filter paper influences measurement of some elements present at low concentrations. Simultaneous measurement of K and Fe in DBS extracts may be used to estimate sample hematocrit.
authors.affiliation: Department of Clinical Biochemistry, Holbæk Hospital, Holbæk, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Pedersen
authors.affiliation: Danish Ageing Research Center (DARC), University of Southern Denmark (SDU), Odense, Denmark; SHARE (Survey of Health, Ageing and Retirement in Europe), Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Andersen-Ranberg
authors.affiliation: Danish National Neonatal Screening Biobank, Statens Serum Institute (SSI), Copenhagen, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Hollergaard
authors.affiliation: Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark. Electronic address: mads.nybo@rsyd.dk.
authors.forename: Mads
authors.initials: M
authors.lastname: Nybo
mesh_terms: D001151:Arsenic / Q000097:blood; D003300:Copper / Q000097:blood; D059788:Dried Blood Spot Testing / Q000592:standards*; D006400:Hematocrit / Q000379:methods; D006801:Humans; D007501:Iron / Q000097:blood; D008274:Magnesium / Q000097:blood; D011188:Potassium / Q000097:blood; D012643:Selenium / Q000097:blood; D014131:Trace Elements / Q000097:blood*; D015032:Zinc / Q000097:blood
chemical_list: D014131:Trace Elements; D003300:Copper; D007501:Iron; D012643:Selenium; D008274:Magnesium; D015032:Zinc; D001151:Arsenic; D011188:Potassium
keywords: Dried blood spots; Elements; Hematocrit; ICP-MS; Method validation