Determination of styrene polymer content for industrial use (2)

7 Spectrophotometry

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In two conical flasks with stoppers, respectively transfer 10 mL of styrene samples

7.

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 1 mg/kg

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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 period of time.

7.

In two different laboratories, different operators, using different instruments and equipment, according to the same test method, tested the same object independently of each other to obtain two test results, the polymer content is 1mg/kg ~ 15mg /kg of the sample, the absolute difference is not greater than 1.

8 Visual method

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1 Analysis steps

8.
1.
1 Table 1 gives a qualitative description of the turbidity direction of different styrene polymer content and styrene and methanol mixtures.
Polystyrene and toluene can also be used to prepare standards that meet the requirements of Table 1 or other known concentrations.
Sample
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Table 1 The relationship between the content of styrene polymer and the turbidity of the mixture of styrene and methanol

8.
1.
2 Take 2 mL of the sample and place it in a dry and clean test tube (5.
7), and use a pipette to add 10 mL of anhydrous methanol to it, stop the test tube with a cork covered with aluminum foil and vigorously shake it for a few seconds
.

8.
1.
3 After shaking the test tube, check the mixed solution in the test tube through a fluorescent tube (5.
8)
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Compare the observed turbidity of the sample mixed solution with the turbidity description given in Table 1, or with the turbidity of other standard samples with known polymer content
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8.
2 Expression of analysis results

Select the turbidity description closest to the sample from Table 1, or report the polymer content of the sample based on the turbidity of other standard samples with known polymer content
.

9 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
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Related links: Determination of styrene polymer content for industrial use (1)