Propylene glycol methyl ether for industrial use (1)

4 Test method

Unless otherwise specified, only reagents confirmed to be analytically pure and grade 3 water specified in GB/T6682-1992 are used in the analysis

4.

Add laboratory samples to a 50mL colorimetric tube with stopper, and perform visual inspection under fluorescent light or sunlight

4.

4.

Using gas chromatography, under selected working conditions, the sample is vaporized and separated by capillary color harmonic column, detected by flame ionization detector, quantified by area normalization method, and subtracted the water content to obtain propylene glycol methyl ether And the content of 2-methoxy-1-propanol

4.

Carrier gas: Nitrogen, in line with the regulations of GB/T9722-2006

4.

4.

4.

4.

4.

The recommended chromatographic column and typical operating conditions of this standard are shown in Table 2, the relative retention value of each component is shown in Appendix A, Table A.

Table 2 Chromatographic column and typical operating conditions

4.

According to the instrument manual, adjust the instrument to the operating conditions shown in Table 2, and start the measurement after the instrument is stable
.
Use a chromatographic data processor or workstation to process the calculation results
.

4.
2.
6 Quantitative methods

Area normalization method

4.
2.
7 Result calculation

The mass fraction w _{i of the} content of propylene glycol methyl ether or 2-methoxy-1-propanol , expressed in %, is calculated according to formula (1):

Where:

x _i —The value of moisture measured in accordance with 4.
5 in terms of mass fraction;

A — The peak area of propylene glycol methyl ether or 2-methoxy-1-propanol ;

∑A _i — the sum of the peak areas of each component
.

Take the arithmetic mean of the two parallel determination results as the determination result
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The absolute difference between the two parallel determination results is not more than 0.
10%
.

4.
3 Determination of chromaticity

According to the provisions of GB/T3143-1982
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