OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

Reviewer(s) Jeffrey Van de Riet, Canadian Food Inspection Agency Cheryl Lassitter, National Oceanic and Atmospheric Administration, US Department of Commerce Sneh Bhandari, Merieux NutriSciences, Crete, IL

Scope of method Target analyte .-Sulfite, measured as SO 2 content. Matrixes .-Raw shrimp head on, raw shrimp head off and boiled shrimp.

Claims .-Quantification of sulfite from 30 to 150 mg/kg and 50 to 300 mg/kg. Within these ranges, the Biofish method was equivalent to OMA 990.28, the optimized Monier-Williams method for determination of sulfites in foods (4). The method is not intended for regulatory use.

Intended users -

Food laboratories.

- Technical staff of fish and aquaculture companies, including primary and processing sector.

Definitions

a) Linearity Defines the ability of the method to obtain test results proportional to the concentration. Linearity of the method extending beyond the set of standards or calibrators supplied with the kit. b) Selectivity Ability of the method to detect analyte without interference from matrix or other components of similar behavior. c) Recovery Recovery is the ratio of the mean 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) Relative Bias Bias is the difference between the candidate method mean result and the mean reference method result, mean cand – mean ref . g) Standard Deviation of Repeatability s r = n

2

1 X X n − − i

∑

(

)

i

1

=

where X i

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

2