ASTM E299-08 Test Method for Trace Amounts of Peroxides in Organic Solvents

Scope:

ASTM E299 – 08 Test Method used to determine numerous peroxide classes of varying reactivity in organic solvents. ASTM E299 – 08 test method calculates active oxygen in the range from 5 to 80 μg/g (ppm) or higher. The test method covers the range of 0 to 5 ppm using a reaction-absorption cell.

Test Procedure:

A sample is dissolved in a mixture of acetic acid and chloroform. The solution is de-aerated and potassium iodide reagent solution is added and allowed to react in the dark for 1 h, thereby releasing an equivalent amount of iodine. The absorbance of the solution is measured at 470 nm and the amount of active oxygen present in the sample is determined by reference to a calibration curve prepared from iodine.

FIGURE 1.  Absorption Cell for Low-Active Oxygen

Specimen size:

Organic solvent containing 0 to 5 μg/g (ppm) active oxygen.

Data:

Calculate the active oxygen content of the sample as follows:

Active oxygen, μg/g (ppm) = A/BC 

Where:

A = active oxygen found, μg,

B = sample used, mL, and

C = density, g/mL.

If a specific peroxide is present, convert the micrograms per gram (parts per million) of active oxygen to peroxide using the appropriate conversion factor.

Peroxide X, μg/g (ppm) = active oxygen in sample, μg/g (ppm) × F

Where F = conversion factor for peroxide X.