GB/T 4324.6-2012Methods for chemical analysis of tungsten - Part 6: Determination of iron content-1,10-phenanthroline spectrophotometry (English PDF)

3.1

potassium iodide.

3.2

chloroform.

3.3

sulfuric acid (rho = 1.84g/mL), pure class distinctions.

Aqueous ammonia 3.4 (rho = 0.90g/mL).

3.5 sodium perchlorate solution

Pipette 200mL perchloric acid (11) with sodium hydroxide solution (400g/L) was adjusted to pH = 7 (using pH paper an examination).

3.6 phenanthroline solution (3g/L)

Weigh 0.3g Orthopenanthroline placed 300mL beaker, add 10mL ethanol, and dissolved

Diluted with water to 100mL, and mix.

3.7 hydroxylamine hydrochloride solution (200g/L)

Purification steps are as follows. Weigh 50g of hydroxylamine hydrochloride placed in 500mL beaker, 150mL

Dissolved in water with ammonia (3.4) was adjusted to pH = 7 (check with pH paper), was added 20mL phenanthroline solution (3.6), heated to boiling, take

Cooling, add 3g of potassium iodide (3.1), dissolved water transferred into a separating funnel and diluted to 250mL, (3.2) and extracted with chloroform Number

Times (20mL, shaking 2min) until the organic phase was colorless. The organic phase was discarded, the aqueous phase into the vial and set aside.

3.8 ammonium sulfate solution (500g/L)

Purification steps are as follows. Weigh 250g ammonium sulfate dissolved in 400mL of water with ammonia (3.4) adjusted pH = 7 (check with pH paper), sodium perchlorate solution was added 2.5mL (3.5), 2mL hydroxylamine hydrochloride solution (3.7), 3mL o-

Philippine solution (3.6), bring to the boil. After adding 3g of potassium iodide to be dissolved, with rapid quantitative filter paper in a separatory funnel, and diluted with water

To 500mL. Add 20mL ~ 30mL chloroform (3.2), the oscillation 2min, after resting stratification, the organic phase discarded, the aqueous phase was repeatedly trichloroacetic

Methane (3.2) was extracted to the organic phase was colorless and the aqueous phase into the vial and set aside.

3.9 citric acid solution (500g/L)

Purification steps are as follows. Weigh 250g of citric acid, placed in 1000mL beaker, add water 200mL

Dissolved, aqueous ammonia (3.4) was adjusted to pH = 7 (check with pH paper), was added 20mL phenanthroline solution (3.7), heated to boiling, add

3g potassium iodide (3.1), dissolved by rapid quantitative filter paper in a separating funnel, and diluted with water to 500mL, with chloroform (3.2) and extracted several times (each 20mL, shaking 2min) until the organic phase was colorless, organic phase was discarded and the aqueous phase into the vial and set aside.