Industrial Acrylonitrile—Determination of Iron Content Graphite Furnace Atomic Absorption Method (2)

7 Analysis steps

7.

According to the operating instructions of the instrument, install and age the graphite tube in the atomic absorption spectrometer, and then set it according to the test conditions recommended in Table 1.

Table 1 Recommended working conditions of atomic absorption spectrometer

7.

7.

7.

7.

Note 1: If the instrument is not equipped with the online help function, you can also manually prepare the series of standard solutions required by the standard curve from the 1ug/mL iron standard solution (7.

7.

7.

Note 2: If the iron content in the sample solution exceeds 400ng/mL, the dilution ratio of the sample can be increased.

7.

7.

8 Expression of analysis results

8.

The iron content w in the sample is calculated in milligrams per kilogram (mg/kg), calculated according to formula (1):

Where:

P _Fe — the measured iron content of the sample solution after dilution, in nanograms per milliliter (ng/mL);

p— The density of the acrylonitrile sample during the measurement , in grams per milliliter (g/mL);

n- with ethanol diluted acrylonitrile dilution of the sample

8.
2 Presentation of results

8.
2.
1 The value of the analysis result shall be rounded according to GB/T8170, and the arithmetic average of the two repeated determination results shall be taken to represent the analysis result
.

8.
2.
2 The iron content in the report of acrylonitrile shall be accurate to 0.
001mg/kg
.

9 Repeatability

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

10 Test report

The test report should include the following:

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

b) 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
.