Division 8 Method performance characteristics (precision)F1

Statistical results of the interlaboratory test:

• the following table give the values for glycyrrhizic acid.

• The following data were obtained from an international method performance study carried out to internationally agreed procedures.

• Year of interlaboratory test	1998
  Number of laboratories	16
  Number of samples	5
  Analyte	glycyrrhizic acid

  Samples	A	B	C	D	F
  Number of laboratories retained after eliminating outliers	13	14	15	16	16
  Number of outliers (laboratories)	3	2	1	—	—
  Number of accepted results	26	28	30	32	32
  Mean value g/l	0,046	0,092 (*) 0,099	0,089	0,249	0,493
  Repeatability standard deviation (S r ) g/l	0,001	0,001	0,001	0,002	0,003
  Repeatability relative standard deviation (RSD r ) (%)	1,5	1,3	0,7	1,0	0,6
  Repeatability limit (r) g/l	0,002	0,004	0,002	0,007	0,009
  Reproducibility standard deviation (S R ) g/l	0,004	0,007	0,004	0,006	0,013
  Reproducibility relative standard deviation (RSD R ) (%)	8,6	7,2	4,0	2,5	2,7
  Reproducibility limit (R) g/l	0,011	0,019	0,01	0,018	0,037

  Sample types:

  A

• pastis, blind duplicates

B

• pastis, split levels (*)

C

• pastis, blind duplicates

D

• pastis, blind duplicates

E

• pastis, blind duplicates