Determination of acrylonitrile peroxide content for industrial use. Spectrophotometric method (2)

5 Reagents

Unless otherwise noted, the reagents used are all analytically pure, the water meets the specifications of the secondary water specified in GB/T6682, and the standard titration solutions, preparations and products used are prepared in accordance with the requirements of GB/T601 and GB/T603.

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15.
1 Alkaline washing distillation method: Take 600mL of acrylonitrile and 300mL of sodium hydroxide solution (5.
7) in the same separatory funnel towel, shake for 5min, and let stand for 10min.
After the solution is separated, the water layer is released, and the upper propylene The nitrile was poured into a brown reagent bottle containing 60g of anhydrous calcium chloride (5.
4), placed for 4 hours, and then distilled in an all-glass system to collect the middle distillate with a boiling range of 75.
5°C to 79.
0°C
.
The prepared non-peroxide acrylonitrile should not be less than 200mL
.

5.
15.
2 Activated alumina column adsorption method: activated alumina is activated at 175℃～315℃ before use
.
Fill the chromatography column with activated alumina to the mark (previously rinse with acrylonitrile sample in a beaker until no powder appears), called A column: Fill another chromatography column (column) with the same method The activated alumina inside is rinsed with peroxide-free acrylonitrile passing through the A column), which is called the B column
.
The acrylonitrile sample is passed through the A column and the B column sequentially at a speed of 5.
0 mL/min-22.
0 mL/min, and finally the peroxide-free acrylonitrile passing through the B column is collected
.
The prepared peroxide-free acrylonitrile should not be less than 200mL
.

Note: The peroxide-free acrylonitrile processed by the above steps is tested according to step 8.
1, and the absorbance should be less than 0.
170
.

6 sampling

Take samples according to the technical requirements specified in GB/T3723 and GB/T6680 and place them at room temperature
.

Related Links: Determination of Acrylonitrile Peroxide Content for Industrial Use Spectrophotometry (1)