AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

Fluor-03 (Feb. 2019) FOR ERP USE ONLY DO NOT DISTRIBUTE

Table 3 Preparation of check standards and spiked UPW

Check std no

Concentration (µg/kg)

Conc. stock solution (mg/kg)

Vol. stock solution (µL)

Vol. UPW (g)

Total (g)

1 2 3 4

5

10 10

125 250

249.875 249.750 249.960 249.875 499.975

250 250 250 250 500

10

160 500

1000 1000

40

125

LOD UPW

0.5

10

25

F. Sample preparation (a) Solid samples. —Weigh 2.5 ± 0.1 g of sample into a suitable container (PP tube). Record weight (W S ) to the nearest 0.001 g. Fill up to a total volume of 50 mL (50 g) with UPW and record the total weight (W UPW ) of the added UPW volume to the nearest 0.001 g. Cap the vial and mix vigorously with a vortex mixer or equivalent for approximately 20 s. Before analysis with ion chromatography, shake the sample well, cover PP tubes with Al foil and place into autosampler sample rack. (b) Liquid sample, i.e. “ready-to-feed” liquids and liquid concentrates. —Dilution beneficial. Weigh 2.5 ± 0.1 g of sample (transfer with disposable pipette) into a suitable container (PP tube). Record weight (W S ) to the nearest 0.001 g. Add UPW to a total volume of 50 mL (50 g) and record the total weight (W UPW ) of the added UPW to the nearest 0.001 g. Cap the vial and mix vigorously with a vortex mixer or equivalent for approximately 20 s. Before analysis with ion chromatography, shake the sample well, cover PP tubes with Al foil and place into autosampler sample rack.

G. Chromatographic conditions (a) System configuration.

Figure 1 System configuration (b) IC operating conditions.

Table 4 IC parameters

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