Analytical Method: Cyanide in spirits

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. 109701  Spectroquant® Cyanide Test
Cat.No. 119533  Cyanide standard solution 1000 mg/l CN-
Disposable syringes
Syringe filter holder 0.45 µm cellulose, acetate membrane  

Measuring range:
0.0020 – 0.1000 mg/l CN- at cell length of 50 mm
0.005  –  0.250 mg/l CN- at cell length of 20 mm
0.010  –  0.500 mg/l CN- at cell length of 10 mm  

Analysis:
Use the above test kit to perform the measurement.
Refer to the package insert for instructions of the optional digestion for the determination of readily liberated cyanide with the reagents CN-1 and CN-2 and for related advice regarding the measurement. The following box shows the analysis specification to be followed, highlighting the steps deviating from those in the package insert.

Pretreated sample
(5 - 30 °C)
5.0 ml Pipette into a test tube1).

Reagent CN-3

1 level green microspoon
(in the cap of the CN-3 bottle)
Add and shake briefly.
Reagent CN-4 1 level blue microspoon      
(in the cap of the CN-4 bottle)
Add and shake vigorously for
3 min
.
(Note: The reagent does not dissolve completely).
Leave to stand for 10 min (reaction time), then withdraw sample with a syringe, filter over a 45-µm syringe filter holder into the cell corresponding to the desired measuring range, and measure in the photometer (the method is selected by the AutoSelector). Divide the result by a correction factor of 1.1.

1) We recommend the use of blank cells. These can be tightly closed with screw caps, preventing the loss of gases.

 

When making the measurements in the 50-mm cell, the sample volume and the volumes of reagents CN-3 and CN-4 must be doubled.

 

Note:
The Cyanide Test is suited for quantification in ethanolic aqueous solutions up to 40 %.

Any sample-dependent interferences (matrix effects) must be determined beforehand by means of standard addition or dilution procedures. The corresponding work instructions can be downloaded at www.qa-test-kits.com.
This method is not suited for liqueurs, since matrix effects produce false-low results.  

Measurement results:

 

Alcoholic
beverage  
  Spiking 
[mg/l]

Recovered
cyanide  
[mg/l]

Recovery rate Mean
recovery rate
         
 Quetsch brandy 0.060
0.280
0.390
0.055
0.279
0.398
92 %
100 %
102 %
 98 %
         
 Slivovitz  0.060
0.280
0.390
0.056
0.264
0.362
93 %
94 %
93 %
 93 %
         
 Pear brandy 0.060
0.280
0.390
0.058
0.271
0.374
97 %
97 %
96 %
 97 %
         
 Mirabelle plum
 brandy 
0.060
0.280
0.390
0.062
0.293
0.400
103 %
105 %
103 %
 104 %
         
 Plum brandy 0.060
0.280
0.390
0.047
0.221
0.306
78 %
79 %
78 %
 78 %1)
 1) low recovery due to strong intrinsic color

 

 

Materials

     
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