SPDS Lutein and Turmeric ERPs

AOAC O FFICIAL M ETHODS OF A NALYSIS (2005)

I NTERLABORATORY C OLLABORATIVE S TUDY Appendix D, p. 11

Appendix 1. Critical values for the Cochran maximum variance ratio at the 2.5% (1-tail) rejection level, expressed as the percentage the highest variance is of the total variance L = number of laboratories at a given level (concentration) r = number of replicates per laboratory L r = 2 r = 3 r = 4 r = 5 r = 6

Appendix 2. Critical values for the Grubbs extreme deviation outlier tests at the 2.5% (2-tail), 1.25% (1-tail) rejection level, expressed as the percent reduction in the standard deviations caused by removal of the suspect value(s) ( see text for calculating the Grubbs statistics) L = number of laboratories at a given level (concentration)

One highest or lowest

Two highest or two lowest

One highest and one lowest

L

94.3 88.6 83.2 78.2 73.6 69.3 65.5 62.2 59.2 56.4 53.8 51.5 49.5 47.8 46.0 44.3 42.8 41.5 40.3 39.1 37.9 36.7 35.5 34.5 33.7 33.1 32.5 29.3 26.0 21.6

81.0 72.6 65.8 60.2 55.6 51.8 48.6 45.8 43.1 40.5 38.3 36.4 34.7 33.2 31.8 30.5 29.3 28.2 27.2 26.3 25.5 24.8 24.1 23.4 22.7 22.1 21.6 19.5 17.0 14.3

72.5 64.6 58.3 52.2 47.4 43.3 39.9 37.2 35.0 33.2 31.5 29.9 28.4 27.1 25.9 24.8 23.8 22.9 22.0 21.2 20.5 19.9 19.3 18.7 18.1 17.5 16.9 15.3 13.5 11.4

65.4 58.1 52.2 47.3 43.0 39.3 36.2 33.6 31.3 29.2 27.3 25.7 24.4 23.3 22.4 21.5 20.7 19.9 19.2 18.5 17.8 17.2 16.6 16.1 15.7 15.3 14.9 12.9 11.6 9.7

62.5 53.9 47.3 42.3 38.5 35.3 32.6 30.3 28.3 26.5 25.0 23.7 22.0 21.2 20.4 19.5 18.7 18.0 17.3 16.6 16.0 15.5 15.0 14.5 14.1 13.7 13.3 11.6 10.2

4 5 6 7 8 9

4 5 6 7 8 9

86.1 73.5 64.0 57.0 51.4 46.8 42.8 39.3 36.1 33.8 31.7 29.9 28.3 26.9 25.7 24.6 23.6 22.7 21.9 21.2 20.5 19.8 19.1 18.4 17.8 17.4 17.1 13.3 11.1

98.9 90.3 81.3 73.1 66.5 61.0 56.4 52.5 48.5 46.1 43.5 41.2 39.2 37.4 35.9 34.5 33.2 31.9 30.7 29.7 28.8 28.0 27.1 26.2 25.4 24.7 24.1 19.1 16.2

99.1 92.7 84.0 76.2 69.6 64.1 59.5 55.5 51.6 49.1 46.5 44.1 42.0 40.1 38.4 36.9 35.4 34.0 32.8 31.8 30.8 29.8 28.9 28.1 27.3 26.6

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 35 40 50

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 50

26.0 20.5

8.6 Cochran statistic = (largest individual within-laboratory variance)/(sum of all the within-laboratory variances).

17.3 Source: Both tables were calculated by R. Albert (October 1993) by computer simulation involving several runs of approximately 7000 cycles each for each value, and then smoothed. Although the table of Appendix 1 is strictly applicable only to a balanced design (same number of replicates from all laboratories), it can be applied to an unbalanced design without too much error, if there are only a few deviations.

© 2005 AOAC INTERNATIONAL