GB 31604.30-2025National food safety standard - Food contact materials and articles - Determination of phthalates and of their migration (English PDF)

3.1 Reagents

3.1.1 n-Hexane (C6H14).

3.1.2 Tetrahydrofuran (C4H8O).

3.2 Standard Substances 19 phthalate esters standard substances (see Appendix A). purity 95%, or standard substances certified by the state and awarded with standard substance certificates.

3.3 Preparation of Standard Solutions

3.3.1 Single standard stock solutions of 19 phthalate esters (5,000 mg/L). respectively and accurately weigh-take 50 mg of each of the 19 phthalate ester standard substances (in accordance with NOTE a in Table A.1, select DINP-1 or DINP-2, DIDP-1 or DIDP-2 standard substances), convert the actual weighed mass in accordance with the purity, accurate to

0.1 mg. Use n-hexane to dissolve them and accurately reach a constant volume of 10 mL, and mix them well. Transfer the solutions to brown glass containers and store them in a 20 C refrigerator away from light. The shelf life is 6 months.

3.3.2 Mixed standard intermediate solution A of 19 phthalate esters. accurately transfer-take 10 mL of DINP-1 or DINP-2 standard stock solution (5,000 mg/L), 10 mL of DIDP-1 or DIDP-2 standard stock solution (5,000 mg/L), 1 mL of DNOP standard stock solution (5,000 mg/L), 1 mL of DNP standard stock solution (5,000 mg/L) and

0.5 mL of each of the other phthalate esters standard stock solutions (5,000 mg/L) into a 100 mL volumetric flask, add n-hexane to reach a constant volume of 100 mL, and mix it well. Among them, the mass concentration of DINP-1 or DINP-2 is 500 mg/L, the mass concentration of DIDP-1 or DIDP-2 is 500 mg/L, the mass concentration of DNOP is 50 mg/L, the mass concentration of DNP is 50 mg/L, and the mass concentration of other phthalate esters is 25 mg/L. Transfer the solution to a brown glass container and store it in a 20 C refrigerator away from light. The shelf life is 6 months.

3.3.3 Phthalate esters series mixed standard working solutions. into five 50 mL volumetric flasks, respectively and accurately transfer-take

0.10 mL,

0.20 mL,

0.50 mL,

2.0 mL of 19 phthalate esters mixed standard intermediate solution A, use n-hexane to reach a constant volume and mix them well. Thus, the phthalate esters series mixed standard working solutions are obtained. Among them, the mass concentration of DINP-1 or DINP-2, DIDP-1 or DIDP-2 is

5.0 mg/L, 10 mg/L and 20 mg/L; the mass concentration of DNOP and DNP is

0.10 mg/L,

0.20 mg/L,

0.50 mg/L,

2.0 mg/L; the mass concentration of the other phthalate esters is

5.1 Sample Pre-treatment

5.1.1 Preparation of test solution Take representative specimens. For solid specimens, such as. resin, plastic and rubber, etc., cut them into fragments, or cut them into fragments and then, use liquid nitrogen to perform cryogenic grinding, so as to control the size of the fragments to

0.1 cm, and evenly mix them. For thin layer solid specimens, such as. coatings and adhesive layers, use a knife to scrape them, or use a knife to scrape them and then, cut them into fragments or use liquid nitrogen to perform cryogenic grinding, so as to control the size of the fragments to

0.3 cm, and evenly mix them. For liquid specimens, such as. coatings and adhesives, directly sample them. Accurately weigh-take

0.2 g ~

0.5 g of specimen (accurate to 0.0001

g) into a centrifuge tube, add 10 mL of tetrahydrofuran, and extract by ultrasonic method for 30 min. For specimens that are soluble or turbid during ultrasound, after extraction, slowly add 40 mL of n-hexane and perform vortex oscillation. At 4,000 r/min, centrifuge for 20 min. Take the supernatant, and at 45 C under reduced pressure, perform rotary evaporation to about 3 mL, and use n-hexane to reach a constant volume of 10 mL. Filter it through a 0.45 m organic phase glass filter membrane for the determination by gas chromatograph-mass spectrometer.

c) Ionization mode. electron impact ionization source (EI);

d) Monitoring mode. selected ion monitoring mode (SIM), and the monitored ions are shown in Table B.1;

e) Ionization energy. 70 eV;

f) Solvent delay. 7 min.

5.3 Qualitative Determination In accordance with the instrument reference conditions, the following conditions shall be satisfied to determine the presence of the corresponding targets in the sample.

a) The difference between the chromatographic peak retention time of the phthalate esters detected in the sample and the chromatographic peak retention time of the target compound in the standard solution is within the range of 0.5%;

b) The selected ions appear in the sample mass spectrogram after background subtraction and the signal-to-noise ratio is 3;

c) The deviation between the relative abundance of the qualitative ions and that of the standard solution with equivalent concentration shall not exceed those specified in Table 1. Table 1 -- Maximum Allowable Deviation of Relative Abundance Ratio of Ions

11.2 Analytical balance. with a division value of 0.0001 g and

0.01 g.

11.3 Centrifuge. speed 4,000 r/min.

11.4 Vortex oscillator.

11.5 Solid phase extraction device.

11.6 Rotary evaporator.

11.7 Glassware. NOTE. after cleaning, use water to rinse it 3 times, soak in tetrahydrofuran for 1 hour and rinse 3 times, dry, and cool to room temperature for later use.

11.8 Solid phase extraction cartridge. PSA/Silica composite filler glass column (500 mg/500 mg, 6 mL) or others with equivalent performance.

12.2 Preparation of test solutions

12.2.1 Aqueous, acidic, and ethanol-containing food simulants (volume fraction of ethanol < 50%) Accurately transfer-take 10 mL of the soaking solution into a 25 mL centrifuge tube, add 4 mL of n-hexane, perform vortex oscillation and extract for 10 min, at 4,000 r/min, centrifuge it for 5 min, and take the n-hexane layer. Then, repeat the extraction twice and combine the extracting solutions. At 45 °C under reduced pressure, perform rotary evaporation on the extracting solution to dryness. Add 1 mL of n-hexane, perform vortex oscillation to re-dissolve it, and take the supernatant for instrument detection.

12.2.2 Ethanol-containing food simulants (50% volume fraction of ethanol < 95%) Accurately transfer-take 10 mL of the soaking solution into a 50 mL centrifuge tube, add 10 mL of water and 8 mL of n-hexane, perform vortex oscillation and extract for 10 min, at 4,000 r/min, centrifuge for 5 min, and take the n-hexane layer. Then, repeat the extraction twice and combine the extracting solutions. At 45 °C under reduced pressure, perform rotary evaporation on the extracting solution to dryness. Add 1 mL of n-hexane, perform vortex oscillation to re-dissolve it, and take the supernatant for instrument detection. 12.2.3 95% (volume fraction) ethanol and isooctane chemical alternative solvents Accurately transfer-take 10 mL of the soaking solution into a flask, and at 45 °C under reduced pressure, perform rotary evaporation to dryness. Add 1 mL of n-hexane, perform vortex oscillation to re-dissolve it, and take the supernatant for instrument detection.

12.2.4 Oil-containing food simulants Weigh-take 5 g (accurate to

0.01

g) of the soaking solution into a 50 mL centrifuge tube, add 20 mL of acetonitrile, perform vortex oscillation and extract for 10 min, at 4,000 r/min, centrifuge for 10 min, and take the acetonitrile layer. Repeat the extraction once and combine the extracting solutions in a flask. At 45 °C under reduced pressure, perform rotary evaporation on the combined acetonitrile extracting solution to about 3 mL as the solution to be purified. Add 10 mL of acetonitrile to the solid phase extraction cartridge for activation, and discard the c0

---the mass concentration of a single phthalate ester in the blank soaking solution, expressed in (mg/L); V

---the constant volume, expressed in (mL); N

---the dilution factor, by which, the test solution is diluted to make the determined value within the linear range of the standard curve; V0

---the sampling size, expressed in (mL).

13.1.2 Oil-containing food simulants The content of a single phthalate ester in oil-containing food simulants is calculated in accordance with Formula (3). Where, X1

---the content of a single phthalate ester in food simulants, expressed in (mg/kg); M

---the mass concentration of a single phthalate ester in the specimen soaking solution, expressed in (mg/kg); M0

---the mass concentration of a single phthalate ester in the blank soaking solution, expressed in (mg/kg); N

---the dilution factor, by which, the specimen solution is diluted to make the determined value within the linear range of the standard curve.

13.2 Calculation of Specific Migration of Phthalate Esters in Food Contact Materials and Products

13.2.1 Calculation of specific migration of phthalate esters in food contact materials and products for non-sealed and sealed products (expressed in mg/kg) For food contact materials and products for non-sealed products and sealed products, such as. lids, sealing rings and connectors, etc., the specific migration of a single phthalate ester, when expressed in mg/kg, is calculated in accordance with Formula (4). Where, X2

---the specific migration of a single phthalate ester in food contact materials and products, expressed in (mg/kg); V1