Table 2.

Distribution of inter-assay coefficients of variation for metabolites in each categorya

Metabolite categoryMetabolites, nMedian (minimum – maximum) interassay coefficient of variation (%)
Amines58.9 (8.2–22.5)
Amino acid derivatives1313.0 (9.6–23.9)
Amino acids2810.4 (6.9–18.0)
Bile acids517.6 (12.1–20.5)
Lipids and lipid metabolites889.6 (4.0–25.0)
Organic acids1113.3 (5.2–24.8)
Purines, pyrimidines, and derivatives39.0 (6.8–20.5)
Vitamins314.8 (11.5–16.1)
Otherb1010.5 (6.6–16.3)
  • aMetabolites with an interassay coefficient of variation >25% were excluded from analysis.

  • bOther metabolites include allantoin, cotinine, creatine, creatinine, hippurate, hydroxyphenylacetate, phenylethylamine, salicylurate, sorbitol, and uracil.