OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

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

=

is the i th value, Xbar is the mean value, and n is the number of values.

where X i

( 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

X

s

where

is the mean analytical value of the known negative matrix; is the intercept of the plot of s r

0

b

m

vs. mean value; and

is the slope of the plot.

3