OMA Consulting Protocol Review: OMACON-2019-2

2.4.6.8 If the regression is not valid, 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. 2.4.7 Measurement Standard Analysis: The calibration status should be tested using the Standard option after a series of measurements (10-15) or if the device has not been running for a minimum of 30 minutes. 2.4.7.1 Press Standard in the analysis option, fit the cuvette correctly and fill with 10 mL of Measurement Solution and press CONTINUE. 2.4.7.2 Wait until the device issues a sound signal. Press CONTINUE and inject Measurement Standard into the cuvette (See Table 5). 2.4.7.3 Wait until the “Biosensor calibrated” or “Biosensor recalibrate” message appears. 2.4.7.4 Replace the contents of the cuvette with 10 mL of new LAC Measurement Solution. If “Biosensor calibrated” message appeared, proceed to Sample Preparation. If “Biosensor recalibrate” message appeared, return to step 2.4.7. or check the proper preparation of the Calibration Standards. 2.4.8 Sample Pretreatment, Dilution and Analysis: A preliminary sample pretreatment or dilution step is needed to perform the analysis of the sample. 2.4.9 Activated charcoal (0-200 mg/L range): Liquid samples need to be pretreated before being analyzed in the 0-200 mg/L range. 2.4.9.1 Add a capsule of charcoal activated in 50 mL of sample and divide

the sample in half to speed up the mixing process. Shake until the active charcoal is homogeneously mixed with the milk sample and let it react for at least 30 minutes before analyzing. Shake it occasionally.

2.4.9.2 Test kits may also contain a pretreatment tube instead of a capsule. In that case, inject 5 mL of milk sample inside the pretreatment tube, shake until the mixture is homogeneous and analyze the sample as usual. 2.4.10 Dilution (0-2 g/L range and 0-6 g/L range): Samples (milk and other dairy products) in the 0-2 g/L and 0 -6 g/L ranges need to be diluted. 2.4.10.1 To do so, mix 1 mL of sample with 9 mL of Measurement

Solution and shake it to homogenize. Once the samples are prepared, they must be analyzed within a maximum of 2 hours.

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