Page 189 - Analytical method for food addtives

126 Analytical methods for food additives

Table 9.3 Performance characteristics for nitrite in meat products 10,15
Method Part 3, page 9 Part 4, page 8
Sample Sausage Corned beef
No. of laboratories 19 14* 14
Units mg/kg mg/kg mg/kg
Mean value 37 7 38.9
S r 2 1.2 1.5
RSD r 5.8 % 17.0 % 4.0 %
r 6 3.3 4.4
S R 3 2.3 3.7
RSD R 7.7 % 2.9 % 9.4
R 8 6.5 10.3

* Data for information only
Key
Mean The observed mean. The mean obtained from the collaborative trial data.
r Repeatability (within laboratory variation). The value below which the absolute difference
between two single test results obtained with the same method on identical test material under
the same conditions may be expected to lie with 95 % probability.
S The standard deviation of the repeatability.
r
RSD The relative standard deviation of the repeatability (S × 100/mean).
r r
R Reproducibility (between-lab variation). The value below which the absolute difference
between two single test results obtained with the same method on the identical test material
under different conditions may be expected to lie with 95 % probability.
S The standard deviation of the reproducibility.
R
RSD The relative standard deviation of the reproducibility (S × 100/mean)
R R