GB/T 693-1996Chemical reagent. Sodium acetate trihydrate (English PDF)

5.3 Clarity test

Weigh 20g of sample. Dissolve in 100mLof water. Its turbidity must not exceed following clarity standards specified in HG/T 3-1168-78.

Guaranteed reagent... No.2;

Analytical reagent... No.3;

Chemical pure... No.5.

5.4 Water insoluble matter

Weigh 50g of sample. Dissolve in 300mLof boiling water. Cool to room temperature. Measure according to provision of GB/T 9738.

5.5 Chloride

5.5.1 Preparation of test solution

Weigh 20g of sample. Dissolve in water. Dilute to 50mL.

5.5.2 Determination method

Take 5mLof test solution. Dilute to 10mL. Add 4.5mL of nitric acid solution (25%) to acidify. Measure according to provisions of GB/T 9729.Solution turbidity must not exceed standard comparison solution.

Preparation of standard comparison solution is to take chloride standard solution that contains following quantities.

Guaranteed reagent... 0.006mg Cl;

Guaranteed reagent, Analytical reagent... 0.01mg Al;

Chemical pure... 0.02mg Al.

Dilute to 10mL. Perform same treatment as same volume test solution.

5.9 Potassium

Measure according to provisions of GB/T 9723.

5.9.1 Instrument conditions

Light source. potassium hollow cathode lamp;

Wavelength. 766.5nm;

Flame. Acetylene-air.

5.9.2 Determination method

Weigh 5g of sample. Dissolve in water. Add 5mLof hydrochloric acid solution (20%). Dilute to 100mL.Take 10mL, four portions in total. Measure according to provisions of 6.2.2 in GB/T 9723-88.

5.10 Calcium

Measure according to provisions of GB/T 9723-88.

5.10.1 Instrument conditions

Light source. calcium hollow cathode lamp;

Wavelength. 422.7nm;

Flame. Acetylene-air.

5.10.2 Determination method

Weigh 25g of sample. Dissolve in water. Add 20mLof hydrochloric acid solution (20%). Dilute to 100mL. Take 20mL (take 8mLfor chemical pure), four portions in total. Measure according to provisions of 6.2.2 in GB/T 9723-88.

5.11 Iron

Take 5mLof test solution (5.5.1). Dilute to 10mL. Use hydrochloric acid solution (15%) to adjust pH value to 2.Measure according to provisions of GB/T 9739.

Red of solution must not be darker than standard comparison solution.

Preparation of standard comparison solution is to take iron standard solution that contains following quantities.

Annex A (Normative)

Treatment and regeneration method for strong acid cation exchange resin

A.1 Instruments

A.1.1 Exchange column material. glass tube or polyethylene tube.

A.1.2 Exchange column inner diameter. 10mm~20mm.

A.1.3 Resin bed height. about 400mm (recombinant resin volume accounts for

2/3 of exchange column height).

A.1.4 Resin particle size. 0.2mm~0.8mm.

A.2 Treatment method

Take an appropriate amount of strong acid cation exchange resin into a beaker (for dry resin, use saturated sodium chloride solution to soak first; then gradually dilute sodium chloride solution in case resin is broken from expanding). Use water to rinse till it is clear. Add water to soak 12h~24h to make it completely expanded. After draining water, soak it in 95% ethanol for 24h. Use water to rinse it till it is alcohol-free. Add hydrochloric acid solution (1+3) to soak 2h~3h.

Use water to rinse it to neutral. Add sodium hydroxide solution (100g/L). Soak

2h~3h. Use water to rinse it to neutral. Then use hydrochloric acid solution (1+3) to rinse and soak 24h.Stir frequently. Use hydrochloric acid solution (1+3) to rinse three times.

Load resin that is processed as above into exchange column. Use 400mLof hydrochloric acid solution (1+3) to rinse resin at a flow of 10mL/min. Then use water to rinse till washing fluid if neutral. Use water to soak, for use.

A.3 Regeneration method

Move invalid strong acid cation exchange resin into a beaker. Use hydrochloric acid solution (1+3) to rinse three times. Soak 21h. Stir frequently. Discharge hydrochloric acid solution. Use hydrochloric acid solution (1+3) to rinse three times.

Load resin that is processed as above into exchange column. Use 400mLof hydrochloric acid solution (1+3) to rinse resin at a flow of 10mL/min. Then use water to rinse till dripping solution is neutral. Use water to soak, for use.

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