GB/T 45235-2025Determination of bisphenol A in electrical and electronic products - High performance liquid chromatography (English PDF)

3.1 Bisphenol A; BPA

5.9 Centrifuge tube. 10 mL, with cap.

5.10 Glass vial. 50 mL, with sealing cap.

5.11 Syringe. 2 mL.

5.12 Liquid chromatography sample bottle. About

1.5 mL, with cap.

5.13 Sealing film.

6.2 Electronic balance. With sensitivity of

0.1 mg.

6.3 Grinder. With 1 mm pore size filter screen.

6.4 Water bath ultrasonic generator, power per unit area >=

0.3 W/cm2.

6.5 Pipettor or pipette tube. 10 mL, 30 mL.

6.6 Rotary oscillator.

6.7 Centrifuge. Speed >= 5,000 r/min.

8.1 Ultrasonic extraction Weigh 1 g (accurate to

0.1 mg) of the crushed specimen in Clause 7 and carefully put it into the bottom of the glass vial (5.10). Use a pipettor or pipette tube (6.5) to accurately transfer 10 mL of tetrahydrofuran (5.2) and slowly add it along the inner wall of the glass vial containing the specimen. Cover the bottle cap tightly and seal it with a sealing film (5.13). Place it in a water bath ultrasonic generator (6.4) for ultrasonic oscillation for 60 min. After the ultrasonic oscillation is completed, place it at room temperature to cool to room temperature.

8.2 Dilution Open the cap of the glass vial in 8.1; use a pipettor or pipette tube (6.5) to accurately transfer 30 mL of methanol-water mixture (5.4); slowly titrate it into the opened glass vial; close the cap. Place the glass vial in a rotary oscillator (6.6) and shake for about

0.5 min to fully mix the extract in the glass vial.

8.3 Centrifugal separation Open the cap of the glass vial in 8.2; use a pipettor or pipette tube (6.5) to transfer about 10 mL of extract into a centrifuge tube (5.9); cover the cap and place it in a centrifuge (6.7); centrifuge at 5,000 r/min for 5 min. Use a syringe (5.11) to take out about 2 mL of the supernatant in the centrifuge tube; filter it through a membrane filter (5.8); and inject it into a liquid chromatography sample bottle (5.12) for testing.

8.4 High-performance liquid chromatography determination

8.4.1 Instrument conditions The test results depend on the used instrument, and it is impossible to give general parameters for high-performance liquid chromatography (with fluorescence detector). The following parameters have been proven to be feasible.

a) Liquid chromatography column. C18, 250 mm×

4.6 mm (i.d.), particle size 5µm, or equivalent performance.

b) Column temperature. 30 °C.

c) Mobile phase. methanol-water (70+30, volume ratio).

d) Flow rate. 1 mL/min.

e) Injection volume. 10.0 µL.

f) Detector wavelength. Excitation wavelength, 275 nm; emission wavelength, 313 nm.

g) Run time. 15 min.