OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

Biolan Microbiosensores BIOFISH 300 SUL Collaborative Study Protocol

February 2019

2.6.2 Upon arrival at the collaborative site, the collaborator will open the shipment, examine the contents for leakage, and inspect each test portion to ensure all are frozen. All test portions will be stored at -20°C overnight. 2.7 Analysis of Test Portions by BIOFISH 300 SUL On Wednesday, each collaborator will analyze their test portions as follows. 2.7.1 Refer to the Test Portion Inventory Sheet for the BIOFISH 300 SUL range to use for each test portion. There are 4 blind coded test portions for each method range. Group the test portions by range keeping them frozen. 2.7.2 Starting with the test portions for the first range, for example, 7-30 mg/kg, allow the appropriate test portions to sit at room temperature for no more than 15 minutes to thaw, with the plastic tube closed, as it was received. 2.7.3 Add 18 mL of SUL extraction solution. 2.7.4 Homogenize the contents with the aid of an UltraTurrax set at 8000-9000 rpm for 15-20 sec. 2.7.5 Let stand a minimum of 15 minutes at room temperature to complete the extraction. Once extracted, the samples are stable up to 1 h at room temperature. 2.7.6 Follow the BIOFISH 300 SUL 7-30 mg/kg method to set up the device (recondition, activation and calibration). 2.7.7 Follow the BIOFISH 300 SUL 7-30 mg/kg method to complete the analyses. Analysis of Test Portions by OMA 990.28 – Performed by 3 Collaborators only Beginning on Wednesday, select collaborators will analyze six 50-g test portions by the OMA 990.28 method. Keep each test portion frozen until ready for analysis. Complete the analyses within three days. Briefly: 2.8.1 Prepare apparatus and solutions according to the OMA 990.28 method. 2.8.2 Thaw each test portion just prior to analysis. 2.8.3 Add 100 mL 5% EtOH in water v/v and blend. 2.8.4 Transfer test suspension to prepared apparatus. 2.8.5 Allow all but 2-3 mL of HCl solution from separatory funnel to drip into flask containing test suspension. 2.8.6 Boil contents of flask for 1.7 h. 2.8.7 Titrate contents of vessel with 0.010 M NaOH to a persistent yellow end point. 2.8.8 Calculate SO 2 content. 2.8.9 Record results on the Data Report Form (Appendix 3.5) 2.7.8 Repeat steps 2.7.2 – 2.7.7 for the other two method ranges. 2.7.9 Record all results on the Data Report Form (Appendix 3.5). 2.8

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DRAFT