OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

Reference Materials

a) GSCCA 1/2016. Peeled Shrimp. Containing 116 mg/kg SO 2.

Safety Precautions

There are no major risks. Sulfites may cause allergy-like reactions including sneezing, runny nose or wheezing; or asthma symptoms in people with underlying asthma; or rarely hives or anaphylaxis. The use of personal protective equipment (PPE) including gloves, laboratory coat and protective eyewear is recommended.

General Preparation

a) Biotest storage and hydration.- The Biotests are dispatched at room temperature and vacuum packed with silica gel crystals to protect them from atmospheric humidity. Once delivered, store unopened between 3-8°C until expiration date. To hydrate the Biotest prior to using (this process should be carried out at least 24 hours prior to use): 1. Discard the silica gel crystals from inside the tube. 2. Fill the tube with SUL Measurement Solution until the Biotest is submerged. 3. Add 20 μL of SUL Calibration Reagent. Once hydrated, the Biotest must be stored vertically at a temperature between 3-8°C for a maximum of 15 days. b) SUL Measurement Solution .-The SUL Measurement Kit supplies 8 or 5 tubes to prepare the SUL Measurement Solution, necessary to hydrate the Biotest and to carry out the measurements.

1. Dissolve contents of 1 tube of MFSUL1 in 250 mL distilled water or 2. Dissolve contents of 1 tube of MFSUL2 in 1 L of distilled water. 3. Mix well. Store at room temperature and use within 15 days.

c) SUL Extraction Solution .-The SUL Extraction Solution is necessary to prepare SUL Calibration Reagent and Standards and also to extract the sulfite from the matrix to be analyzed.

1. Dissolve contents of 1 tube of SEFSUL1 in 1 L of water or 2. Dissolve contents of 1 tube of SEFSUL2 in 2 L of water. 3. Mix well. Store at room temperature and use within 15 days.

d) SUL Calibration Reagent.- The SUL Calibration Kit supplies 4 tubes of powdered Calibration Reagent along with two empty tubes to prepare the Sulfite Standards. Add 10 mL of SUL Extraction Solution (SEFSUL) to 1 tube of SUL Calibration Reagent (CFSUL) and mix. To prevent loss of reagent, introduce the pipette tip through the perforated stopper when adding the extraction solution volume. Store at refrigerated temperature (3-8°C) and use within 7 days. e) Sulfite Standard .-The sulfite standards are prepared daily by diluting the Calibration Reagent, and this is the reagent used to calibrate the equipment. 1. Prepare SUL Standard 1 (range 30-150 mg/kg) by diluting 53.4 µL of SUL Calibration Reagent (CFSUL) to a final volume of 20 mL with SUL Extraction Solution.

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