Industrial monoisopropylamine (3)

5.

5.

Under selected working conditions, the sample is vaporized and separated by a chromatographic column, detected by a thermal conductivity detector, and quantified by an external standard method

5.

5.

5.

5.

5.

5.

5.

5.

The chromatographic columns recommended by this standard and typical chromatographic operating conditions are shown in Table 2

Other chromatographic columns and chromatographic operating conditions that can achieve the same degree of separation can be used

Table 2 Ammonia content determination chromatographic column and typical chromatographic operating conditions

5.

5.
7.
5.
1 Preparation of ammonia standard sample solution

Weigh 100g of water in each standard sample bottle, weigh an appropriate amount of ammonia water into it, the above weighing is accurate to 0.
0002g, and prepare an ammonia standard sample solution with a mass fraction of ammonia similar to that of the sample
.
The ammonia standard sample solution is stored in the refrigerator for later use
.

5.
7.
5.
2 Determination

Start the gas chromatograph, and debug the instrument according to the chromatographic operating conditions listed in Table 2 or other suitable conditions.
After the baseline is stable, perform chromatographic analysis on the sample and the ammonia standard sample solution under the same conditions
.
Use a chromatographic data processor or a chromatographic workstation to calculate the results
.

5.
7.
6 Result calculation

The mass fraction of ammonia w ₅ , the value is expressed in %, calculated according to formula (3):

Where:

A _s —the area of ​​the ammonia peak in the ammonia standard sample solution;

A—Ammonia peak area in the sample;

c _s -the exact value of the ammonia mass fraction of the ammonia standard sample solution, %
.

Take the arithmetic average of the two parallel determination results as the determination result
.
The absolute difference between the two parallel determination results is not more than 0.
02%
.