Determination of acrylonitrile content less than 3mg/kg. Headspace gas chromatography (Amphos detector) (3)

A.

A.

If a series of calibration solutions with different contents are obtained (see A.

Since this calculation process does not require an internal standard, it is usually only applicable when the acrylonitrile content in the sample is not linear with the acrylonitrile peak height

Where:

m _A quantity of the solution of acrylonitrile polymer in the sample solution prepared for testing in -A.

m"a—The amount of acrylonitrile measured in the part of the blank solution prepared in A.

mp—The mass of the polymer weighed in A.

wa—The acrylonitrile content in the polymer, in milligrams per kilogram (mg/kg)

A.

A.

If there is a linear relationship between the peak height of acrylonitrile and the content, wa is calculated by the following formula (A.

In addition to the description in A.

h'a—The peak height of acrylonitrile in the calibration solution prepared in A.

ha-A.

h"a—The peak height of acrylonitrile in the blank solution prepared in A.

h"'a— The peak height of the remaining acrylonitrile in the zero-content sample solution prepared in A.

m'a—A.
5.
3 After adding different amounts of acrylonitrile to the reference sample solution for calibration prepared by A.
5.
3, the content of acrylonitrile in part of the samples used for the test, including the zero-content sample solution measured separately, in milligrams (mg);

m'o—The mass of the zero-content reference sample dissolved in the calibration reference sample solution prepared in A.
5.
3, in milligrams (mg);

m'"o—The mass of the zero-content reference sample dissolved in the zero-content sample solution prepared in A.
5.
4, in milligrams (mg)
.

A.
6.
2.
2 Using internal standards

If there is a linear relationship between the peak area and the relative content of acrylonitrile, and all sample solutions use A.
5.
1 internal standard solution instead of PC as the solvent, use formula (A.
3) to calculate:

In addition to the meanings specified in A.
6.
1 and A.
6.
2.
1, the symbols in the formula also indicate:

h's—A.
5.
3 The peak height of the internal standard substance (propionitrile) in the calibration solution prepared with the internal standard solution, in millimeters (mm);

hs—A.
5.
5 The peak height of the internal standard substance (propionitrile) in the sample solution prepared with the internal standard solution, in millimeters (mm);

ms — the mass of the internal standard substance ( propionitrile ) in the polymer sample solution prepared in A.
5.
5 , in milligrams (mg);

m's—the mass of the internal standard substance (propionitrile) in the reference sample solution prepared in A.
5.
3, in milligrams (mg);

If it is assumed that h"a=0, h"'a=0 and ms=m's, then formula (A.
3) is simplified to formula (A.
2)
.

Related links: Determination of acrylonitrile content below 3mg/kg Headspace Gas Chromatography (Ammonia Phosphorus Detector) (2)