Analytical Method: Chromate in cement

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. 114552  Spectroquant® Chromium Cell Test
Cat.No. 114758  Spectroquant® Chromium Test
Cat.No. 100456  Nitric acid 65 % for analysis
Cat.No. 109584  MColorpHastTM pH Indicator strips, pH 2.0 - 9.0
Cat.No. 116754  Water for analysis
Membranfilter 0.45 μm

 

Sample preparation:
Mix 10.0 g exactly weighted sample, previously dried to constant weight at 105 °C with 40 ml water for analysis and stir for 15 min /- 1 on a magnetic stirrer. Allow the solids to settle and filter off suspended solids using a fluted paper filter (acid washed, for analytical purposes). If the filtrate is still turbid, filter through a membrane filter with
0.45 μm pore diameter or centrifuge to get a clear extract sample solution. For further analysis adjust the pH of the leach ate by drop wise adding of 65 % nitric acid to pH 5 - 7.
 
Analysis:
Determine with the above mentioned test kits.
 
Calculation:
10.0 g sample with 40 ml water for analysis mixed and extracted is equivalent to 250 g sample per litre. Multiply the result measured in mg/l by 4 to get the concentration of the analyte in mg/kg.
 
Chromate content in mg/kg CrO4 =  analysis value in mg/l CrO4 x  4 

Materials

     
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