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1.3 STANDARD SOLUTIONS

1.3 STANDARD SOLUTIONS

          The following solutions are used as reference standards in limit tests, and should, unless experience has shown it to be unnecessary, be prepared immediately before use.

Aluminium Standard Solution (2 ppm Al) Dilute 1.0 ml of a 0.352 per cent w/v solution of aluminium potassium sulfate in 0.1 M sulfuric acid to 100.0 ml with water.

Aluminium Standard Solution (10 ppm Al) Dilute 1 volume of a 1.39 per cent w/v solution of aluminium nitrate to 100 volumes with water immediately before use.

Ammonium Standard Solution (1 ppm NH4) Dilute 40.0 ml of ammonium standard solution (2.5 ppm NH4) to 100.0 ml with water.

Ammonium Standard Solution (2.5 ppm NH4Dilute 1.0 ml of a 0.0741 per cent w/v solution of ammonium chloride with water to 100.0 ml.

Ammonium Standard Solution (10 ppm NH4) Dilute 1.0 ml of a 0.297 per cent w/v solution of ammonium chloride with water to 100.0 ml.

Arsenic Standard Solution (1 ppm As) Dilute 10.0 ml of arsenic standard solution (10 ppm As) with water to 100.0 ml.

Arsenic Standard Solution (10 ppm As) Dissolve 330.0 mg of arsenic trioxide in 5 ml of 2 M sodium hydroxide and dilute to 250.0 ml with water. Dilute 1.0 ml of this solution to 100.0 ml with water.

Calcium Standard Solution (100 ppm Ca), Ethanolic Dissolve 250.0 mg of dried calcium carbonate in 1.2 ml of 5 M acetic acid and dilute with water to 100.0 ml. Dilute 10.0 ml of the resulting solution to 100 ml with ethanol.

Fluorine Standard Solution (400 ppm F) Dissolve 442 mg of sodium fluoride in sufficient 1 M sodium hydroxide to produce 500.0 ml.

Store in polyethylene bottles and keep for 3 days only.

Iron Standard Solution (10 ppm Fe) Dissolve 863.4 mg of ammonium iron(III) sulfate [FeNH4(SO4)2.12H2O] in water, add 10 ml of 1 M sulfuric acid and dilute with water to 100.0 ml. Transfer 10.0 ml of this solution into a 1000-ml volumetric flask, add 10 ml of 1 M sulfuric acid, dilute with water to volume, and mix.)

Lead Nitrate Stock Solution (100 ppm Pb) Dissolve 159.8 mg of lead(II) nitrate [Pb(NO3)2] in 100 ml of water to which has been added 1 ml of nitric acid, then dilute with water to 1000.0 ml.

Prepare and store this solution in glass containers free from soluble lead salts.

Lead Standard Solution (1 ppm Pb) Dilute 10.0 ml of lead standard solution (10 ppm Pb) with water to 100.0 ml.

Lead Standard Solution (2 ppm Pb) Dilute 10.0 ml of lead standard solution (10 ppm Pb) with water to 50.0 ml.

Lead Standard Solution (10 ppm Pb) On the day of use, dilute 10.0 ml of lead nitrate stock solution (100 ppm Pb) with water to 100.0 ml.

Selenium Standard Solution (1 ppm Se) Dissolve 40.0 mg of metallic selenium in 100 ml of a 50 per cent v/v solution of nitric acid in a 1000-ml volumetric flask, warming gently on a water-bath if necessary to effect solution, add water to volume, and mix. Pipette 5 ml of this solution into a 200-ml volumetric flask, add water to volume, and mix.)

APPENDICES • 1.3 STANDARD SOLUTIONS
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หมายเหตุ / Note : TP II 2011 PAGE 325-326