OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

• CALIBRATION: Calibration is performed by adding the SUL Standard 3 to the measuring cuvette at two different times. To fit the calibration line, the device will take into account the target, the change in intensity caused by the first addition of the SUL Standard 3 and the sum of the changes in intensity caused by both additions. 1. Press Calibrate in the ANALYSIS option. 2. Check that the cuvette is correctly fitted and filled with 10 ml of Measurement Solution and press CONTINUE to begin the calibration process. 3. Wait until the device issues a sound signal. Press CONTINUE and pipette the SUL Standard 3 into the measuring cuvette (ADDITION 1) (See Table 6) in this order, using a micropipette. 4. Wait until the device records the change in intensity and issues another sound signal. 5. Press CONTINUE again and pipette the SUL Standard 3 into the measuring cuvette again (ADDITION 2) (See Table 6). 6. Wait until the process ends. The parameters of the calibration line will appear on the screen with the ''Calibration OK'' or ''Calibrate again'' message. 7. Change the content of the cuvette with 10 ml of new Measurement Solution.

It is important to add the Calibration Standard immediately after pressing the CONTINUE button to record the current intensity correctly at the time of adding it.

Table 6. SUL Standard 3 and Sample Volumes.

Range 7-30 mg/kg: Standard 3 / Verifying Solution / Sample 4 ml

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