GB/T 41701-2022 "Determination of nicotine, propylene glycol and glycerol in electronic cigarette liquid by gas chromatography" describes the gas chromatographic determination method of nicotine, propylene glycol and glycerol in electronic cigarette liquid. According to the sub-standard, this paper briefly summarizes the smoke detection methods in the electronic smoke detection.

Electronic smoke liquid detection principle:

The electronic cigarette liquid is diluted with isopropanol solution containing internal standard, and the nicotine, propylene glycol and glycerol in the diluent are determined simultaneously by gas chromatography with hydrogen flame ionization detector (GC-FID), and the internal standard method is used for quantification.


Reagents and materials for electronic smoke liquid detection:

Carrier gas, auxiliary gas, isopropanol, internal standard, internal standard solution, nicotine, propylene glycol, glycerin, standard working solution.


Electronic smoke liquid detection instrument and equipment.

Analytical balance, oscillator, conical flask with stopper, gas chromatograph, chromatographic column.

Electronic smoke detection: analysis steps

1. Sample pretreatment

Weigh 0.1 g of sample, accurate to 0.000 1 g, put it into a 50 ml conical flask with a stopper, add 10 mL of internal standard solution, use an oscillator to oscillate for 20 min at the speed of 180 r/min~200 r/min, and take 1 mL of sample for analysis.

2. Meteorological chromatograph conditions

The conditions of gas chromatography are optimized to meet the good separation and detection sensitivity of the target. For example, the programmed temperature rise can be adjusted from 40 ℃/min to 5 ℃/min to achieve better separation of chromatographic peaks. Once the optimization conditions are determined, the same chromatographic conditions shall be used to analyze all standard samples and electronic smoke liquid detection samples.

3. Preparation of standard working curve

Make standard working curve once a day. After every 20 sample determinations, a medium concentration working standard solution shall be added. If the measured value differs from the original value by more than 5%, the whole standard working curve shall be redone.

4. Determine the sample solution according to the test conditions of the instrument, calculate the ratio of the peak area of nicotine, propylene glycol and glycerol to the internal standard peak area, and substitute it into the standard working curve to calculate the concentration of nicotine, propylene glycol and glycerol. Each sample was measured twice in parallel. During the determination process, the peak area of the internal standard should be monitored for each sample to remain unchanged. If it changes, take the electronic cigarette liquid and dilute it with isopropanol for verification, and confirm that the sample component does not elute at the peak position of the internal standard.

If the measured amount of the sample exceeds the range of the standard working curve, the range of the standard working curve should be readjusted.

Electronic smoke liquid detection: calculation results and expression

The content of nicotine, propylene glycol and glycerol in the electronic cigarette liquid shall be calculated according to the following formula.

X=(p x V)/m

X - content of target substance in the sample of electronic cigarette liquid, unit: mg/g;

P - the mass concentration of the target substance in the diluent of the sample of electronic cigarette smoke liquid obtained from the standard working curve, in mg/mL;

V - volume of diluent, unit: mL;

M - mass of electronic smoke liquid sample, unit: g.

The results are expressed as the arithmetic mean of the two parallel determinations. The accuracy of nicotine is 0.1 mg/g, and the accuracy of propylene glycol and glycerol is 1 mg/g.

The relative average deviation of two parallel determination results shall not exceed 5%.

Electronic smoke liquid detection: inspection report

The inspection report shall include the following contents:

1. Identify all information required for the tested sample

2. According to GB/T 41701-2022 Electronic Cigarette Liquid - Determination of Nicotine, Propylene Glycol and Glycerin - Gas Chromatography

3. Determination results of nicotine in electronic cigarette liquid;

4. Determination results of propylene glycol in electronic cigarette liquid;

5. Determination results of glycerol in electronic cigarette liquid;

6. Test date;

7. Measurement personnel.