Study of preanalytical conditions for selenium determination in urine.
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.
Sabé
R
R
Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain.
Rubio
R
R
García-Beltrán
L
L
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
D012643:Selenium; D006851:Hydrochloric Acid