Analytical Method: Nickel (total) in effluents, high organic content

Instruments and Reagents:

Cat.No. 173016 Spectroquant^® VIS Spectrophotometer Prove 100 or
Cat.No. 173017 Spectroquant^® UV/VIS Spectrophotometer Prove 300 or
Cat.No. 173018 Spectroquant^® UV/VIS Spectrophotometer Prove 600 or
Cat.No. 109748 Spectroquant^® Photometer NOVA 30 or
Cat.No. 109751 Spectroquant^® Photometer NOVA 60 or
Cat.No. 173632 Spectroquant^® Colorimeter Move 100
Cat.No. 114946 Rectangular cells 10 mm and/or
Cat.No. 114947 Rectangular cells 20 mm and/or
Cat.No. 114944 Rectangular cells 50 mm
Cat.No. 114554 Spectroquant^® Nickel Cell Test
Cat.No. 114785 Spectroquant^® Nickel Test
Cat.No. 100731 Sulfuric acid 95 - 97 % for analysis
Cat.No. 107209 Hydrogen peroxide 30 % (Perhydrol^®) for analysis
Cat.No. 105590 Sodium hydroxide solution 32 % for analysis
Cat.No. 109535 MColorpHast^TM Universal Indicator strips pH 0 - 14
Cat.No. 116754 Water for analysis

Sample preparation:

Place 25 mL sample in a 400-mL beaker along with 5 mL sulfuric acid 95 - 97 % and 5 mL Perhydrol^®, mix and slowly heat on a heating plate until the sulfuric acid begins to fume. Allow to cool, add 5 mL Perhydrol^® and heat again until SO₃ is released. Depending on the organic content of the sample, repeat this process up to three times. The fully digested sample should be clear and practically colorless.
Transfer the mixture to a 50-mL volumetric flask. Adjust to pH 4 - 7 with sodium hydroxide solution 32 % (control with Universal Indicator strips pH 0 - 14). Dilute the solution with water for analysis fill up to the mark and mix well.

Analysis:

Determine with the above mentioned test kits.

Calculation:

Nickel (total) content in mg/l Ni = analysis value in mg/l Ni x 2