title: Interlaboratory variability of valproic acid determinations.
abstract: 19 pooled plasma specimens were sent as unknowns to 13 participating research laboratories. The interlaboratory variability between the results was very high. Only 4 out of 13 laboratories had 6--12% of their results within the 95% confidence limit for each sample. The precision of repeated determinations was fairly good. 6 out of 10 participating laboratories had a coefficient of variation of less then 5%. The reproducibility and the agreement between the different procedures for quantitative analysis of dipropylacetate is similar to that reported for other major antiepileptic drugs.
mesh_terms: D007753:Laboratories / Q000592:standards*; D008722:Methods; D011786:Quality Control; D014631:Valerates / Q000097:blood*; D014635:Valproic Acid / Q000097:blood*
chemical_list: D014631:Valerates; D014635:Valproic Acid