Page 372 - Analytical method for food addtives

252 Analytical methods for food additives

Table 26.7 Performance characteristics for sodium saccharin in juice, soft drink and
dessert 18
Sample Juice

No. of laboratories 5 5 5
Units mg/L mg/L mg/L
Mean value 25.9 59.6 89.9
S 0.71 0.45 0.71
r
RSD 2.72 % 0.75 % 0.79 %
r
S 1.82 3.81 6.52
R
RSD 6.98 % 6.39 % 7.26 %
R
Recovery 99.6 % 96.1 % 99.9 %
Sample Soft drink
No. of laboratories 7 6 6
Units mg/L mg/L mg/L
Mean value 35.4 58.5 73.3
S 2.07 2.92 0.91
r
RSD 5.84 % 4.98 % 1.24 %
r
S 7.31 7.96 6.73
R
RSD 20.63 % 13.62 % 9.19 %
R
Recovery 107.4 % 104.5 % 100.5 %
Sample Dessert
No. of laboratories 7 6 7
Units mg/kg mg/kg mg/kg
Mean value 53.0 114.8 152.6
S 3.97 3.47 24.75
r
RSD 7.49 % 3.02 % 16.22 %
r
S 7.13 17.68 24.75
R
RSD 13.43 % 15.40 % 16.22 %
R
Recovery 94.8 % 104.3 % 103.8 %
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 r The relative standard deviation of the repeatability (S × 100/mean).
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 R The relative standard deviation of the reproducibility (S × 100/mean).
R
Horrat The HORRAT value for reproducibility is the observed RSD value divided by the RSD value
R
R
calculated from the Horwitz equation.