BS EN ISO 4946:2016 pdf free

BS EN ISO 4946:2016 pdf free.Steel and cast iron一Determination of copper一2,2′-Biquinoline spectrophotometric method
In parallel with the determination and following the same procedure, carry out two blank tests using the same quantities of all the reagents but using, to the nearest 0,001 g, approximately 0,5 g of pure iron (4.1) instead of test portion.
Introduce the test portion (7.1) into a 250 ml beaker. Add 10 ml of hydrochloric acid (4.2) and 5 ml of nitric acid (4. 3). Cover the beaker with a watch-glass and heat until acids action ceases.
NOTE For samples of high chromium content, first dissolve in hydrochloric acid (4.2) and then, when all effervescence has ceased, oxidize by adding nitric acid (4.3), drop by drop.
Add 10 ml of perchloric acid (4.4) and evaporate to fuming. Continue fuming for 3 min.
Cool, dissolve the salts with 20 ml of water, transfer the solution quantitatively to a one-mark volumetric flask of suitable capacity (see Table 1), dilute to the mark with water and mix.
Filter by decantation through a dry filter to remove any residue or precipitate, e.g. graphite, silica,tungstic acid. Collect the filtrate in a dry beaker, discarding the first fractions of the filtrate.
Carry out the spectrophotometric measurement of the test solution (7.3.1) at a wavelength of about 545 nm, in a cell of 2 cm optical path length, after adjusting the spectrophotometer (Clause 5) to zero absorbance in relation to the compensating solution (7.3.3).
For copper contents below 0,06 % (mass fraction), 4 cm cells may be used if the sensitivity of the spectrophotometer is not sufficient with 2 cm cells.
Into each of a series of 100 ml beakers, add 0,5 g±0,01 g of high purity iron (4.1) and 10 ml of hydrochloric acid (4.2). Cover with a watch-glass and heat gently until dissolved, then oxidize by adding nitric acid (4.3) drop by drop. Add the following volumes of the standard copper solution (4.10) to the beakers, respectively: 0 ml, 2 ml, 5 ml, 10 ml, 20 ml, 30 ml, 40 ml and 50 ml.
Add 10 ml of perchloric acid (4.4) and evaporate to fumes. Continue fuming for 3 min.
Cool, dissolve the salts with 20 ml of water; transfer the solutions quantitatively to 100 ml one-mark volumetric flasks, dilute to the mark with water and mix.
From each volumetric flask, take 10,0 ml of the solution and transfer respectively into a series of 50 ml one-mark volumetric flasks. The zero term represents the compensating solution.BS EN ISO 4946 pdf free.