GB 5009.153-2016Determination of phytic acid in vegetable foods (English PDF)

3.1 Reagents

3.1.1 Sodium hydroxide.

3.1.2 Sodium chloride.

3.1.3 Ferric trichloride.

3.1.4 Hydrochloric acid.

3.1.5 Sulfosalicylic acid.

3.2 Preparation of reagents

3.2.1 30g/L sodium hydroxide solution: weigh 30 g of sodium hydroxide; use water to dilute and fix-volume to 1 000 mL.

3.2.2 0.7 mol/L sodium hydroxide solution: weigh 40.91 g of sodium hydroxide; use water to dilute and fix-volume to 1 000 mL.

Take a representative edible part; use a tissue masher to pulverize and homogenate;

mix it evenly; put it into a clean container; seal it and mark it.

5.1.2 Liquid sample

Take a representative sample; mix it evenly; put it into a clean container; seal it and mark it.

5.2 Sample storage

The sample shall be stored in a refrigerator at -18°C.

Note: During sample preparation and storage, the sample shall be protected from contamination and the test object shall be prevented from loss.

6.1 Extraction

Weigh 10.0 g of the sample; place it in a triangular flask with a plug; add 40 mL of sodium sulfate-hydrochloric acid extraction solution (3.2.5); shake and extract for 2 h;

centrifuge the extract at 5 000 r/min for 5 min; collect all the supernatant and use sodium sulfate-hydrochloric acid extraction solution to fix-volume to 50 mL; filter it through a quick filter paper and set aside.

6.2 Purification

Take 0.5 g of anion-exchange resin (3.5) and wet-pack it into an empty column tube (4.5); respectively use 15 mL of a sodium chloride solution (3.2.2) and 20 mL of water to wash the ion-exchange column. Take 5 mL (for fresh shrimp sample, take 10 mL) of filtrate; add 1mL (for fresh shrimp sample, add 2mL) of sodium hydroxide solution (3.2.1); use water to dilute to 30 mL (for fresh shrimp sample, to 60mL); mix and transfer it to the activated ion-exchange column; then, respectively use 15 mL of water and 15 mL of sodium chloride solution (3.2.3) to elute the exchange column at a flow rate of 1 mL/min; discard the effluent. Finally, use 25 mL of sodium chloride solution (3.2.2) to elute; collect all the eluate in a 25 mL graded tube with a plug; fix-volume to the scale.

Note: When the resin is filled, a sieve plate, with a hole diameter of 20 µm ~ 50 µm, should be placed between the upper and lower layers, and the resin should be compacted.

7.1 Preparation of the standard curve

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