OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

Figure 8. Correlation between theoretical addition of SO 2

and mean results of BIOFISH 300 SUL for boiled

and raw shrimp

Discussion The aim of the present work was to extend the PTM certification for the BIOFISH 300 SUL method to

a new analytical range with LOQ at or below 10 mg/kg in order to meet regulatory needs. The linearity

study demonstrated a linear dose-response from 0 (non-detect) to 30 mg/kg sulfite. Accuracy and bias

results from analysis of incurred samples indicate the kit provides accurate and precise sulfite

quantification for both evaluated matrixes, in comparison to the official modified Monier-Williams

and RSD i

values of

method (1), for values above 10 mg/kg. For values lower than 10 mg/kg, the low RSD r

values of spiked samples, together with the linearity

the replicates of the incurred samples and low RSD r

starting at 2 mg/kg and the good recoveries obtained at this low level support the applicability of the

method at this lower quantification range.

These results were confirmed by performing the calculation of the LOD and LOQ. A LOQ of 1 mg/kg

was estimated for both matrixes, although the LOQ was validated at 7 mg/kg.

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