Determination of polymerization inhibitor (p-tert-butylcatechol) content in styrene for industrial use. Spectrophotometric method (2)

5 Apparatus and equipment

5.

5.

5.

5.

6 sampling

Take samples according to GB/T3723 and GB/T6680

7 Analysis steps

7.

7.

7.

Note: Clean the glassware with pure acetone or methanol .

7.

7.

7.

Pipette 15mL styrene sample into an Erlenmeyer flask, follow the steps specified in 7.

w=w ₁ ×0.

Where:

w—the value of the content of polymerization inhibitor in the sample, in milligrams per kilogram (mg/kg);

w ₁ —The value of the inhibitor content obtained from the standard online apricot, in milligrams per kilogram (mg/kg);

0.

8 Expression of analysis results

Report the analysis results as the arithmetic average of the two repeated determination results, and round off according to the provisions of GB/T8170 to the nearest 0.

9 Precision

In the same laboratory, the same operator uses the same equipment, according to the same test method, and the same test object is tested independently in a short time.
The absolute difference between the two independent test results does not exceed the following repeatability Limit (r), on the premise that the repeatability limit (r) does not exceed 5%:

15mg/kg<X≤100mg/kg is 10% of its average value

10 report

The report should include the following:

a) All information about the sample, such as the name of the sample, batch number, sampling location, sampling date, sampling time, etc.
;

b) The number of this part;

c) Analysis results;

d) Details and descriptions of any abnormal phenomena observed in the measurement;

e) the name of the analyst and analysis date
.