GB/T 40971-2021Methods for the determination of prohibited substance in furniture products and related materials—Polycyclic aromatic hydrocarbons (English PDF)

3.1 Polycyclic aromatic hydrocarbons; PAHs

A series of hydrocarbon compounds and their derivatives in which two or more benzene rings are fused together, and the rings may also have short alkyl or cycloalkyl substituents.

Note: 18 kinds of polycyclic aromatic hydrocarbons are shown in Table A.1 of Appendix A.

8.3 Purification

It can be selective to purify the samples with interfering substances. Before purification, rinse the silica gel solid-phase extraction cartridge (5.8) with 5 mL of n-hexane (5.1) to keep it wet; take 2 mL of the supernatant after extraction (8.2) and transfer it to the silica gel solid-phase extraction cartridge (5.8); elute with 5 mL of n-hexane (5.1), control the flow rate to be 0.5 drops/s, and discard the above passing-through-column liquid. Then, elute with 10 mL of petroleum ether (5.2), collect the petroleum ether eluent, and add 1 mL of toluene (5.3) to the collected petroleum ether eluent; slowly blow the liquid to about 1 mL with a nitrogen concentrator (6.6), and finally, make up to 2 mL with toluene (5.3).

8.4 Filtration

Filter the liquid after constant volume processing with an organic microporous membrane (5.11) and analyze it by a gas chromatography-mass spectrometer (6.1).

8.5 Determination

8.5.1 Gas chromatography and mass spectrometry reference conditions

Ensure the set parameters of the used instrument to be able to separate the tested component and other components effectively during the chromatographic determination. Since the test results depend on the used instrument, it is impossible to give the general parameters of the instrumental analysis. The following parameters have been proven to be suitable for the testing:

a) Chromatographic column: DB-EUPAH or equivalent, 20 m (column length) × 0.18 mm (inner diameter) × 0.14 µm (film thickness);

b) Temperature of injection port: 290 °C;

c) Chromatographic column heating program: initial column temperature shall be 50 °C and held for 1 min; heat up to 200 °C at a rate of 20 °C/min and hold for 0.5 min; then, raise the temperature to 310 °C at a rate of 8 °C/min and hold for 5 min;

d) Temperature of transmitter interface: 280 °C;

e) The temperature of the ion source shall be 230 °C, the ionization method shall be EI, and the ionization energy shall be 70 eV;

f) Temperature of quadrupole rod: 150 °C;

g) Determination method: Selected ion monitoring (SIM);

h) Sample injection method: splitless injection;

i) The carrier gas shall be the helium, and the purity shall be >=99.999%; the carrier gas flow rate shall be 1.0 mL/min;

j) Injection volume: 1 µL;

k) Solvent delay time: 4.0 min.

8.5.2 Qualitative and quantitative analysis by the GC-MS method

According to the analysis conditions of 8.5.1, determine 18 kinds of PAHs mixed standard working solution (5.7) and the filtered solution (8.4). Integrate the peak area of the quantitative ion (see Appendix A); take the peak area as the ordinate and the corresponding standard solution concentration as the abscissa, to draw a standard working curve, and the correlation coefficient shall be >=0.995; use the external standard method for quantification. If the retention time of the chromatographic peak in the solution to be tested is similar to that of the standard working solution (5.7), and the type and abundance ratio of the selected ions (see Appendix A) of the target compound in the solution to be tested are consistent with those of the standard working solution, it can be determined that the target compound exists in the solution to be tested. Typical GC-MS selected ion chromatograms of 18 PAHs are shown in Appendix B.

8.5.3 Blank test

Carry out the blank test according to the above steps, except that no sample is added.

9.1 Calculation of PAH content

Calculate the content of each PAH in the sample according to formula (1): […]