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Analytical Method: Halogen (total) in oils

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. 114730  Spectroquant® Chloride Cell Test
Cat.No. 114897  Spectroquant® Chloride Test
Cat.No. 108326  Toluene dried
Cat.No. 100867  Diisopropyl ether for analysis  (must be dried prior to use with molecular sieve Cat.No. 105708)
Cat.No. 109966  Nitric acid 1 mol/l
Cat.No. 114901  Flat - bottomed tubes
Diphenyl sodium solution
Membrane filter with 0.45 μm pore diameter
 
Hints:
According to the regulations for the disposal of used oil (regulation of 27.10.87), oil disposed of may not contain more than 20 mg/kg PCB or 2 g/kg total halogen. The procedure given below can be used to determine total halogen including inorganic halogens, providing they are soluble in oil.
 
Sample preparation:
The sample must be water - free; should this not be the case, remove all water with a drying agent e.g. anhydrous sodium sulphate or calcium oxide.
Place 2.0 ml toluene, 2.0 ml diisopropyl ether and 4.0 ml diphenyl sodium solution in a flat - bottomed tube fitted with a tight-sealing screw cap. Pipette exactly 1.0 ml oil sample into the mixture, close off the tube and mix.
Allow to stand for 30 minutes at room temperature but shake periodically. Add 10 ml of 1 mol/l nitric acid, close off the tube and shake vigorously for 1 minute. Once the phases have separated, remove 5 ml from the lower aqueous phase using a plastic syringe with a steel cannula. Filter through an membrane filter and use the filtrate for the halogen analysis.
 
Analysis:
Determine with the above mentioned test kits.
 
Calculation:
Halogen (total) content in mg/l Cl = analysis value in mg/l Cl x 10
 
Literatur:
Ligget L.M.: Analyt. Chem. 26(1954)748-750 Gödde, U., Golloch, A.: Fresenius Z. Anal. Chem. 339(1991)15-18

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