SPSFAM ERP

15. For each sample, pipet 3 mL of Extraction Solution into separate molecular weight filters (MWF). Cap and centrifuge at 1500 g for approximately 20 minutes. 16. After 20 minutes, discard the filtered solution and any remaining liquid in the filter. 17. Reassemble the MWF and fill with approximately 4 mL of sample filtrate. Centrifuge at 1500 g for at least 30 minutes or until more than 1 mL of filtrate has been collected beneath the filter. 18. Pipet 1 mL of this filtrate into a 4 dram vial and evaporate the solution to complete dryness under a flow of nitrogen at 55 ± 3°C. This may be achieved using an N-Evap 112 Nitrogen Evaporator or a heating block. 19. Once vials are completely dry, add 5 mL water to each. Cap and vortex for at least 15 seconds. Allow vials to sit for at least 15 minutes and repeat vortexing procedure. 20. Dilute samples as necessary so that all analytes are within the calibration curve. It may be necessary to perform multiple dilutions on a given sample to accomplish this. 21. Filter the diluted sample using a disposable syringe and 0.45 μm GHP filter into an injection vial. G-3. Sample Preparation (for high sugar matrices, >30% individual sugar compound or >50% total sugar content on as is basis) 1. Weigh 2.5 ± 0.1 g of sample into a suitable container such as a 500-mL Erlenmeyer flask. Record weight to at least the nearest 0.001 g. 2. Add 250 mL of water to the flask. 3. Add 0.250 mL of Internal Standard Stock Solution with a positive displacement pipet or electronic repeater pipet with equivalent accuracy. The same Internal Standard Stock Solution must be used for the preparation of both standards and samples. 4. Add a magnetic stir bar, cap with stopper, and mix vigorously on a stir plate for approximately 60 minutes. 5. Add 250 mL of ethanol to the flask. Cap again and shake vigorously to mix. Allow sufficient time for the sample to settle before filtering. 6. Pour the solution through qualitative filter paper and a funnel, and collect filtrate into a suitable container, such as a plastic cup. If needed, add Celite onto filter paper to aid filtration. Filtration may be further aided by transferring a portion of the sample from the Erlenmeyer flask to an appropriately sized centrifuge tube and centrifuging until some of the solids have spun down, approximately 5 minutes. 7. For each sample, pipet 3 mL of Extraction Solution into separate molecular weight filters (MWF). Cap and centrifuge at 1500 g for approximately 20 minutes. 8. After 20 minutes, discard the filtered solution and any remaining liquid in the filter. 9. Reassemble the MWF and fill with approximately 4 mL of sample filtrate. Centrifuge at 1500 g for at least 30 minutes or until more than 1 mL of filtrate has been collected beneath the filter.