Analytical Method: Palladium in water and waste water

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. 109751  Spectroquant® Photometer NOVA 60
Cat.No. 106268  Sodium acetate trihydrate for analysis
Cat.No. 100063  Acetic acid for analysis
Cat.No. 116754  Water for analysis
Cat.No. 820162  4.4'-Bis(dimethylamino)-thiobenzophenone (Michler's thioketone)
Cat.No. 103053  N.N-Dimethylformamide for analysis
Cat.No. 100979  Isoamylalcohol for analysis
Cat.No. 106649  Sodium sulfate water free for analysis
Cat.No. 109531  MColorpHastTM pH-indicator strips pH 0 - 6
Cat.No. 109137  Sodium hydroxide solution 1 mol/l
Cat.No. 109072  Sulfuric acid 0.5 mol/l
Cat.No. 114724  Empty round cells 16 mm with screw cap
Reagent 1:
Dissolve 83 g sodium acetate trihydrate about 500 ml water for analysis, adjust at the pH-meter to pH 3.0 with acetic acid and fill up to 1 l with water for analysis.
Reagent 2:
Dissolve 100 mg 4.4'-bis(dimethylamino)-thiobenzophenone in 100 ml N.N-dimethylformamide.
Palladium reacts with Michler's thioketone at pH 3.0 ± 0.2 under formation of a purple-red complex, which is extractable by isoamylalcohol. This reaction can be used for the extraction photometric determination of palladium.
Measurement range:
Method no. 133
0.05 - 1.25 mg/l Pd at cell length 10 mm and 525 nm
In an empty round cell mix 5.0 ml of the sample (weakly acidic) with 1.0 ml reagent 1 and check the pH-value with pH-indicator strips (set point pH 3.0; correction with NaOH 1 mol/l or H2SO4 0.5 mol/l resp.). After that add 0.20 ml reagent 2 as well as 5.0 ml isoamylalcohol and shake for one 1 min. Separate the organic phase, dry it by using a spatula-tipful of sodium sulfate and then determine in the photometer against a blank.
According to the literature mentioned below interfering cations are maskable by Titriplex® III.
In the photometers Prove 100, Prove 300, Prove 600, Pharo 100, Pharo 300 and NOVA 60 the method is stored.
For the measurement select method no. 133 on the instrument.
Cheng, K.L. - B.L. Goydisch: Microchem. J. 10, 158 (1966)


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