Page 95 - Analytical method for food addtives

E200–3: Sorbic acid and its salts 53

Table 6.4 Performance characteristics for sorbic acid in orange squash, cola drinks,
beetroot, pie filling and salad cream 11
Sample Orange squash Cola drink

No. of laboratories 8 7 9
Units mg/kg mg/kg mg/kg
Mean 316.9 278.4 534.3 517.1
Mean recovery % 99 98.4 94.9 88.8
S 4.48 4.46 6.55
r
RSD 4% 1% 1%
r
r 13 12 18
S 15.24 18.75 55.94
R
RSD 5% 4% 11 %
R
R 43 52 157
Ho 0.8 0.6 1.7
R
Sample Beetroot Pie filling Salad cream
No. of laboratories 8 7 9
Units mg/kg mg/kg mg/kg
Mean 393.2 421.3 1000.4 1147.3 1704.2 2011.5
Mean recovery % 102.9 100.3 95.1 98.7 97.4 103
S 12.54 24.91 127.18
r
RSD 3% 2% 7%
r
r 35 70 356
S 49.03 44.68 213.70
R
RSD 12 % 4 % 12 %
R
R 137 125 598
Ho 1.9 0.7 2.2
R
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 r The standard deviation of the repeatability.
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 R The standard deviation of the reproducibility.
RSD The relative standard deviation of the reproducibility (S × 100/mean).
R R