OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

“Biotest reconditioned. Ready to activate” will appear on the screen. ( 3 ) Replace the contents of the

cuvette with 10 mL of SUL Measurement Solution.

( b ) Activation.-- ( 1 ) Press activate, verify the proper placement of the cuvette and press CONTINUE to begin the activation. ( 2 ) Wait for the equipment to emit an acoustic signal, press CONTINUE, and inject

sulfite standard (4 mL of SUL Standard 3 for the 7-30 mg/kg range; 2 mL of SUL Standard 1 for the 30-

150 mg/kg range; or 1 mL of SUL Standard 2 for the 50-300 mg/kg range) into the measurement cuvette

and wait for the process to end. The message “Biotest activated. Ready for calibration” will appear on

the screen. ( 3 ) Replace the contents of the cuvette with 10 mL of SUL Measurement Solution.

( c ) Calibration .--( 1 ) Press calibrate, verify the proper placement of the cuvette with 10 mL of SUL Measurement Solution, and press CONTINUE. ( 2 ) Wait for the equipment to emit an acoustic signal.

Press CONTINUE and add sulfite standard into the measurement cuvette (4 mL of SUL Standard 3 for the

7-30 mg/kg range; 2 mL of SUL Standard 1 for the 30-150 mg/kg range; or 1 mL of SUL Standard 2 for the

50-300 mg/kg range). This is addition 1. Note : 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. ( 3 ) Wait for the equipment to register the change in intensity and emit an acoustic signal

again. Press CONTINUE and add sulfite standard again (4 mL of SUL Standard 3 for the 7-30 mg/kg range;

2 mL of SUL Standard 1 for the 30-150 mg/kg range; or 1 mL of SUL Standard 2 for the 50-300 mg/kg

range). This is addition 2. ( 4 ) Wait until the parameters of the calibration appear on the screen together

with a message of “calibration OK” or “calibrate again”. ( 5 ) Replace the contents of the cuvette with 10

mL of new SUL Measurement Solution. If the regression is not valid (“calibrate again” appears), change

the measurement cuvette, put it on Stand by for 30 seconds and calibrate again. If the regression is valid

(“calibration OK” appears), continue to Standard Measurement.

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