title: Study of preanalytical conditions for selenium determination in urine.
abstract: OBJECTIVE
  Assessment of preanalytical and storage conditions for selenium determination in urine.
  
  
  METHODS
  A design is established for the study of the effect of HCl as sample preservative, and for the stability of urine samples with time and temperature of storage. The effect of sample sonication before taking aliquots is also evaluated. All measurements are performed using hydride generation atomic fluorescence spectrometry. Selenium concentrations measured from 52 urine samples of healthy population in Barcelona are used for an estimation of the selenium reference level.
  
  
  RESULTS
  HCl addition to urine samples has no effect on Se stability. Significant differences are due to time and temperature of storage. The Se reference level in urine samples from population in Barcelona area is estimated to be 22.8 +/- 6.7 microg Se g(CT)(-1) (CT: creatinine).
  
  
  CONCLUSIONS
  No significant differences are observed in selenium content when HCl is added as preservative. The Se content remains constant at room temperature for one day, for a week at 4 degrees C and for a fortnight when stored at -20 degrees C.
authors.affiliation: Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Sabé
authors.forename: R
authors.initials: R
authors.lastname: Rubio
authors.forename: L
authors.initials: L
authors.lastname: García-Beltrán
mesh_terms: D000704:Analysis of Variance; D006801:Humans; D006851:Hydrochloric Acid / Q000737:chemistry; D011786:Quality Control; D012643:Selenium / Q000652:urine*; D013030:Spain; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D012643:Selenium; D006851:Hydrochloric Acid