Page 263 - Analytical method for food addtives

E334–7, E354: L-tartaric acid and its salts 173

Table 13.3 Performance characteristics for L-tartaric acid in grape juices 1
Sample White grape juice White grape juice Red grape juice Red grape juice
No. of laboratories 8 10 9 9
Units g/L g/L g/L g/L
Mean value 4.19 2.55 3.77 2.15
S 0.0621 0.0513 0.0566 0.026
r
RSD 1.48 2.01 1.50 1.21
r
r 0.17 0.14 0.16 0.07
S 0.1148 0.1253 0.1363 0.0931
R
RSD 2.74 4.91 3.62 4.33
R
R 0.32 0.35 0.38 0.26
Identified in interlaboratory test conducted by International Fruit Union, Paris, France.
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 The relative standard deviation of the reproducibility (S × 100/mean).
R R