AS ISO 19976.1:2020 pdf free download.Copper, lead and zinc sulfide concentrates – Determination of cadmium Part 1: Flame atomic absorption spectrometric method.
5.8 Cadmium, standard solution, 1 ml contains 1 mg of Cd.
Weigh, to the nearest 0,1 mg, 1,000 0 g of cadmium metal (5.7) into a 250 ml beaker. Add 10 ml of water and 5 ml of nitric acid (5.4). Cover and warm gently (if necessary) until the cadmium metal is dissolved. Heat to remove nitrogen oxides, then allow to cool and add about 50 ml of water. Transfer the solution to a 1 000 ml one-mark volumetric flask, add 40 ml of hydrochloric acid (5.2), fill up nearly to the mark with water, mix and cool to room temperature, then fill up exactly to the mark with water and mix again.
5.9 Cadmium, standard solution, 1 ml contains 100 ig of Cd.
Pipette 10,0 0 ml of cadmium standard solution (5.8) into a 100 ml one-mark volumetric flask. Add 20 ml of hydrochloric acid (5.2), fill up nearly to the mark with water, mix and cool to room temperature, then fill up exactly to the mark with water and mix again.
5.10 Cadmium, standard solution, 1 ml contains 10 tg of Cd.
Pipette 10,00 ml of cadmium standard solution (5.9) into a 100 ml one-mark volumetric flask. Add 18 ml of hydrochloric acid (5.2), fill up nearly to the mark with water, mix and cool to room temperature, then fill up exactly to the mark with water and mix again.
5.11 Cadmium calibration solutions.
Prepare a series of calibration solutions by adding, from a pipette, 0,0 ml, 2,00 ml, 4,00 ml, 6,00 ml, 7,00 ml, 8,00 ml, 9,00 ml and 10,00 ml of cadmium standard solution (5.10) into a series of 100 ml onemark volumetric flasks. Dilute to the mark with hydrochloric acid (5.3) and mix thoroughly.
8.3.1 Dissolution of test portion
Transfer the test portion into a 200 ml polytetrafluoroethylene beaker (2) and moisten with 5 ml of water.
Add 10 ml of hydrochloric acid (51,) and heat for 5 mm at 60 °C to 70 °C. Add 10 ml of nitric acid (5A) and heat gently. Add 3 ml of hydrofluoric acid (5.5), then heat gradually until the solution is about 5 ml at 60 °C to 70 °C. Add perchioric acid (5.6) repeatedly until the residue is not present. Heat until the strong white fumes have exhausted completely, then allow to cool.
Add 40 ml of hydrochloric acid (52) [for lead concentrate samples, add 50 ml of hydrochloric acid (5.3)]. Wash down the cover and sides of the beaker and then heat until the onset of boiling, then allow to cool.
8.3.2 Preparation of test solutions
Transfer the solution (8.3.1) to a 200 ml one-mark volumetric flask, dilute to the mark with water and mix thoroughly [for lead concentrate samples, filter the solution through an insoluble filter paper (6.5)]. Wash the precipitate with hydrochloric acid (53) and collect the filtrate in a 200 ml one-mark volumetric flask. Dilute to the mark with hydrochloric acid (53) and mix thoroughly. Then transfer an appropriate aliquot of this solution (see Table 1) to the corresponding one-mark volumetric flask. Add an appropriate amount of hydrochloric acid 52) as indicated in Table 1, fill up nearly to the mark with water, mix and cool to room temperature, then fill up exactly to the mark with water and mix again.AS ISO 19976.1 pdf download.