AOAC RI ERP E-Book - DS DF

OMAMAN-38 B: Collaborative Study Protocol Expert Review Panel Use Only September, 2017

fraction that would be collected as SDFS, however, in this case these are maltodextrins that would be hydrolysed by the PAA/AMG mixture.

Figure 2007.xxE. Chromatograms on TSK-Gel G2500PWXL columns of glucose/glycerol mixtures. A mixture of glycerol (100 mg) and glucose (100 mg) was analysed according to the RINTDF procedure. The ethanolic filtrate (for SDFS determination) was concentrated to dryness and re-dissolved in 32 mL of deionised water. A sample of this was analysed by HPLC; a) directly with no desalting and no Bio-Rad ® de-ashing pre-cartridges in place; b) a sample (5 mL) was desalted by mixing with 1.5 g of Amberlite ® FPA53 (OH − ) and 1.5 g of Ambersep ® 200 (H + ) resins over 5 min and the supernatant was analysed by HPLC with no Bio-Rad ® de- ashing pre-cartridges in place; c) Sample b) was analysed with a Bio-Rad ® de-ashing pre-cartridges in place. Desalting with resins in a polypropylene tube, as described here, removes > 95% of the salt from the sample, thus ensuring more efficient use of the expensive Bio-Rad ® de-ashing pre-cartridges. This desalting step increases the effectiveness of the de-ashing cartridges and allows up to 10-times more samples to be chromatographed before the need to regenerate or replace the de-ashing cartridges. AOAC Research Institute ERP Us Only

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