Analytical Method: Silver (total) in red and white wine

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

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. 114831  Spectroquant® Silver 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. 109533  MColorpHastTM pH-indicator strips pH 5 - 10
Cat.No. 116754  Water for analysis 
 
Samples of wine have to be treated with acid for determination. The various components of wine can cause an undervaluation, if no sample preparation is done.
 
Sample preparation:
In a 400-ml Erlenmeyer flask evaporate 100 ml of the sample to about 1 ml on the heating plate at low heat. Mix the residue with 10 ml sulfuric acid 95 - 97 % and heat until white SO3 smoke arises. After cooling add 2 ml Perhydrol®, mix and heat again on the heating plate. If the sample turns brown, again add 2 ml Perhydrol® after cooling and heat till the SO3 smoke arises. Afterwards the residue should be clear and colorless to light yellow. Finally evaporate the solution to a moist crystalline residue. After cooling dissolve the residue in 25 ml water for analysis and adjust to pH 6.5 with sodium hydroxide solution 32 % (pH-indicator strips). Transfer the solution into a 100-ml standard volumetric flask, fill up to the mark with water for analysis and mix.
 
Analysis:
Determine with the above mentioned test kits
 
Calculation:
Silver (total) content in mg/l Ag = analysis value in mg/l Ag

Materials

     
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