ERP Sulfite Methods-Meeting Materials_4-2020
ERP for Sulfites in Seafood Methods Materials
55
Intended users
‐ Food laboratories, for regulatory use.
‐ Technical staff of fish and aquaculture companies, including primary and processing sector.
Definitions ( a )
Linearity .—Linearity of the method extending beyond the set of standards or calibrators
supplied with the kit. The ability of the method to obtain test results proportional to the concentration.
( b ) Recovery .—Recovery is the ratio of the mean candidate method result to the true value,
expressed as a percentage, [mean cand /known spike] x 100 or [mean ref /known spike] x 100.
( d ) Accuracy .—Accuracy is the ratio of the mean candidate method result to the reference
method result, expressed as a percentage, [mean cand / mean ref ] x 100.
( e ) Bias .—Bias is the difference between the candidate method mean result and the true value, mean cand – known spike. ( f ) Standard Deviation of Repeatability .—s r = n
2
(
)
1 X X n i
1
i
where X i is the i th value, Xbar is the mean value, and n is the number of values.
( g ) Relative Standard Deviation of Repeatability .—RSD r = [s r /mean cand ] x 100 ( h ) Relative Standard Deviation of Intermediate Reproducibility .—RSD i = [s i /mean cand ] x 100
Where mean mean cand is the mean value and s i the standard deviation obtained from two different
day/analyst/device data sets.
( i )
Limit of Detection (LOD) .—Mean + 2s r , or
b s m
0 3.3 1 1.65
X
0 X
b s
where
is the mean analytical value of the known negative matrix;
is the intercept of the plot of s r
m
vs. mean value; and
is the slope of the plot.
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04/16/2020
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