Scope:

ASTM E1784-08 is the standard test method that covers the procedure to calculate the total amount of peroxide in acrylonitrile. It can be applied for peroxides in the range 0.1 to 0.6 ppm in acrylonitrile. Peroxides are an undesirable impurity in acrylonitrile. 

Test Procedure:

Peroxides in the sample react with potassium iodide to form the yellow I₃^– ion. The intensity of the colour, which is proportional to the concentration of the I₃^– ion, is measured at 365 nm. Results are expressed as total peroxides as H₂O₂.

Specimen size:

ASTM E1784-08 requires 25 mL of acrylonitrile sample and 25 mL peroxide-free acrylonitrile as a blank.

Data:

The following equation is used to calculate the total peroxides content in acrylonitrile in ASTM E1784-08, 

where:

V = average volume sodium thiosulfate required for standardization, mL,

N = exact normality 0.1 meq/mL sodium thiosulfate titrant,

S = volume peroxide stock solution taken for standardization = 25 mL, and

17.08 = mg H2O2/meq.

Conclusion:

ASTM E1784-08 serves as a standard test method in order to determine the total peroxides in acrylonitrile.