GB/T 39931-2021Volatile organic compounds from wooden furniture—On-site and rapid detection method (English PDF)

3.1 Wooden furniture

except for the decorative parts and accessories in the main components, the rest are furniture made of wood, artificial boards and other wooden materials [Source: GB/T 28202-2020, 2.1.2]

6.2 On-site rapid collection equipment for VOCs from wood furniture

The on-site rapid collection equipment for VOCs from wood furniture shall comply with the provisions of GB/T 39763.

6.3 Rapid analyzer for VOCs from wood furniture

6.3.1 Formaldehyde rapid analyzer

The minimum resolution of formaldehyde rapid analyzer is 0.01mL/m3. The measuring range is 0.01mg/m³~0.60mg/m³. The uncertainty shall be less than 20%. The response time t95% <=3min. Use formaldehyde standard gas or phenol reagent spectrophotometry (7.2 in GB/T 18204.2-2014) to compare and test the instrument. The relative deviation is <=15%.

6.3.2 Other rapid analyzers for aldehydes and ketones

Rapid analyzer for aldehydes and ketones VOCs: portable gas chromatography, equipped with photoionization detector (PID). The measuring range of single aldehyde and ketone VOCs is 1µmol/mol~100µmol/mol. The indication error is not more than 10%. The uncertainty shall be less than 20%. The detection limit of acetaldehyde and acrolein when quantitatively collecting 1L of gas meets the requirements of Table 1.

NOTE: Other portable chromatographs that meet the detection requirements can also be used.

6.3.3 Non-aldehyde and ketone rapid analyzer

Non-aldehyde and ketone VOCs rapid analyzer: portable gas chromatography, equipped with FID detector. The measuring range of single non-aldehyde and ketone VOCs is 0.5µmol/mol~100µmol/mol. The indication error is not more than 10%. The uncertainty shall be less than 20%. […]

7.3 Background concentration purge

Close the sampling hood of the on-site rapid collection equipment for VOCs from wood furniture (position 8 in Figure 1). Open the air inlet (position 5 in Figure 1) and exhaust port (position 11 in Figure 1). At an air inlet rate of 1L/min, purge nitrogen with a purity of 99.999% into the sampling hood. The time shall not be less than 9min. Ensure that the air in the hood is replaced with high-purity nitrogen, and the background concentration purging is completed.

7.4 Load retention

After the background concentration in the sampling hood of the on-site rapid collection equipment for VOCs from wooden furniture is purged clean, simultaneously close the air inlet (position 5 in Figure 1) and exhaust port (position 11 in Figure 1). The sampling hood is kept tightly closed for 10min.

Enrich the VOCs released from the surface of wooden furniture into the sampling hood.

7.5 Sampling and rapid analysis of VOCs

7.5.1 General

The rapid analysis of formaldehyde (7.5.2) does not need to be separated and enriched due to the small sampling amount. It can be sampled from the rapid analysis of other aldehydes and ketones VOCs (7.5.3) or non-aldehydes and ketones VOCs rapid analysis (7.5.4).

The rapid analysis of other aldehydes and ketones VOCs (7.5.3) and the rapid analysis of non-aldehydes and ketones VOCs (7.5.4) shall be collected separately and sampled after enrichment.

7.5.2 Rapid analysis of formaldehyde

After load retention, turn on the formaldehyde rapid analyzer (including sampling pump and flow meter) within 30s. Rapidly collect the VOCs from wood furniture and analyze the gas in the sampling hood of the equipment. The reading displayed on the formaldehyde rapid analyzer is the formaldehyde […]