Detection of 22 VOCs in indoor air using gas chromatography-mass spectrometry

Instruments and equipment

1. Gas chromatography-mass spectrometry (GC1290/MS8100, Sunny Hengping Instrument), equipped with capillary split/non split injection ports (full EPC), constant current and constant pressure functions, column temperature box with 20 stage programmed heating, and EI source. Column 2: DB-624 (30m * 0.25mm * 1.4μ m)

3 secondary thermal analyzer

4 Electronic Analytical Balance (AE224, Sunny Hengping Instrument)

5 helium gas (purity 99.999%)

6 22 VOC mixed standard samples

Experimental conditions

1. Thermal analysis conditions

Purging gas: nitrogen; Cold trap temperature: initial temperature -30 ℃, desorption temperature 300 ℃; Blow flow rate: 30 mL/min; Capture flow rate 60ml/min, time 4min; Injection time: 5 minutes; Backblowing flow rate: 100ml/min, time: 10min, transmission line temperature: 200 ℃.

2 Chromatographic conditions

Injection port temperature: 250 ℃; Carrier gas: helium; Split ratio: 5:1; Flow rate: 0.8ml/min; Heating program: Initial temperature of 45 ℃, hold for 3 minutes, heat up to 90 ℃ at a rate of 5 ℃/min, then heat up to 260 ℃ at a rate of 20 ℃/min, hold for 2 minutes.

3 MS conditions

Electron bombardment ion source; Electron energy: 70 eV; Ion source temperature: 200 ℃; Transmission line temperature: 200 ℃; Full scan mode, scanning range: 41-300 amu.