Uncertainty components Ketamine Pethidine Cocaine Methandone Diazepam Estazolam Heroin Morphine Methamphetamine
uLC(Uncertainty from LC) 0.017 0.09 0.005 0.01 0.007 0.02 0.01 0.01 0.03
uGC(Uncertainty from GC) 0.16 0.30 0.25 0.13 0.02 0.34 0.34 0.36 0.05
ubb(Uncertainty of homogeneity) 0.00054 0.0007 0.0004 0.0011 0.0004 0.0009 0.0004 0.002 0.0004
us(Uncertainty of stability) 0.00004 0.002 0.0003 0.0031 0.0007 0.0008 0.005 0.007 0.0001
uc(Combined uncertainty) 0.2 0.3 0.25 0.15 0.05 0.35 0.35 0.4 0.1
k (Coverage factor) 2 2 2 2 2 2 2 2 2
U (expanded uncertainty) 0.4 0.6 0.5 0.3 0.1 0.7 0.7 0.8 0.2
Certified value (%) 99.5 99.3 99.5 99.7 99.9 99.3 95.1 98.5 99.5
Table 6: Evaluation of uncertainty for value assignment of 9 illicit drugs CRMs.