Analytical Method: Zinc (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 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. 114566  Spectroquant® Zinc Cell Test
Cat.No. 100861  Spectroquant® Zinc Cell Test
Cat.No. 114832  Spectroquant® Zinc 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 %
Cat.No. 109533  MColorpHastTM pH-indicator strips pH 5 - 8
Cat.No. 116754  Water for analysis
 
*not compatible with Move 100
   
Sample preparation:
In a 400-ml glass beaker evaporate 10 ml of the sample to about 1 ml on the heating plate at low heat. Mix the residue with 2 ml sulfuric acid 95 - 97 %. After cooling add 5 ml Perhydrol®, mix and heat again on the heating plate. After the reaction (foaming) has faded, once more add 5 ml Perhydrol® and heat under addition of a glass pearl, until a white SO3 smoke arises. If the sample turns brown, again add 5 ml Perhydrol® after cooling and heat till the SO3 smoke arises.
Afterwards the residue should be clear and colorless to light yellow. After cooling dissolve the residue in 10 ml water for analysis and adjust to pH 5 - 8 with sodium hydroxide solution 32 % (pH-indicator strips). Transfer the solution into 50-ml standard volumetric flask; fill up to volume with water for analysis and mix.
 
Analysis:
Determine with the above mentioned test kits.
 
Calculation:
Zinc (total) content in mg/l Zn = analysis result in mg/l Zn x 2.5

Materials

     
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