Industrial methylamine aqueous solution test method (2)

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The impurity of methylamine aqueous solution was determined by gas chromatography , detected by thermal conductivity detector, and quantified by external standard method

The minimum detectable concentration of impurities in each amine is shown in Table 1

Table 1 The lowest detectable concentration of impurities in industrial methylamine aqueous solution

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Equipped with a thermal conductivity detector, the temperature accuracy of the thermostat is ±0.

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Column tube: a stainless steel column with a column length of 2m and an inner diameter of 2mm or 3mm, or a column length and inner diameter that can meet the separation requirements selected by the user

Weigh about 0.

Packing of the chromatographic column: after the outlet end of the chromatographic column (the end with the detector) is blocked with a little glass wool and gauze, vacuumize, tap the chromatographic column lightly with a small wooden pole, and slowly pour the estimated phase until the stationary phase Can not be installed slowly, remove the chromatographic column and plug glass wool on the other end
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The packing amount of the stationary phase is about 2.
2g for a column with an inner diameter of 2mm and about 4.
8g for a column with an inner diameter of 3mm
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Aging of the chromatographic column: The newly prepared chromatographic column should be aged for at least 8 hours under a carrier gas (nitrogen) with a column temperature of 100°C and a flow of about 30 mL/min.
The end of the column should be separated from the detector during aging
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3 Chromatographic data processor or recorder
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4 Injector: 10uL micro syringe
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4 Standard sample

The standard sample of methylamine aqueous solution containing each impurity component is prepared by weighing method, and its concentration is close to the concentration of the tested sample
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The pure sample requirements for preparing the standard sample are: monomethylamine , dimethylamine , trimethylamine , ammonia solution samples are injected 2uL under the following instrument operating conditions without impurity peaks
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When there is no pure sample, the impurity blank can be reduced
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