This standard specifies the reagents and materials, instruments and equipment, analysis steps, result calculation, recovery rate and precision, allowable deviation, etc. of the GC-MS determination method for 10 forbidden glycol ethers and esters in cosmetics, namely ethylene glycol dimethyl ether, 2-methoxyethanol, 2-methoxypropanol, 2-ethoxyethanol, 2-methoxypropyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, dimethoxy diglycol, 2-(2-methoxyethoxy) ethanol and triethylene glycol dimethyl ether.
This standard is applicable to the determination of 10 forbidden glycol ethers and esters in cosmetics.
See Table A.1 in Annex A for the limits of detection and quantitation of the method in this standard.
2 Principle
The sample is extracted with ethyl acetate-methanol mixed solvent by ultrasound, determined by gas chromatograph-mass spectrometer, and quantified by external standard method.
3 Reagents and materials
Unless otherwise specified, analytically-pure reagents shall be adopted.
3.1 Ethyl acetate: chromatographically pure.
3.2 Methanol: chromatographically pure.
3.3 Anhydrous sodium sulfate.
3.4 20% ethyl acetate methanol solution (V/V, volume ratio): measure 200mL ethyl acetate (3.1) and mix with 800mL methanol (3.2).
3.5 Standard samples/substances of 10 forbidden glycol ethers and esters: the purity shall not be less than 98%. See Table B.1 in Annex B for the Chinese names, English names, CAS numbers, molecular formulas, relative molecular masses and chemical structural formulas of ethylene glycol dimethyl ether, 2-methoxyethanol, 2-methoxypropanol, 2-ethoxyethanol, 2-methoxypropyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, dimethoxy diglycol, 2-(2-methoxyethoxy) ethanol and triethylene glycol dimethyl ether.
3.6 Standard stock solutions (2,000mg/L respectively): accurately weigh 20mg (accurate to 0.1mg) various standard products (3.5), place them in 10mL brown volumetric flasks respectively, dissolve to the scale with methanol (3.2), and shake well.
3.7 Mixed standard stock solution (100mg/L): accurately pipette 0.5mL each of the standard stock solutions (3.6) respectively, put them into a 10mL brown volumetric flask respectively, dilute to the scale with methanol (3.2), and shake well.
3.8 Mixed standard working solution: accurately pipette an appropriate amount of mixed standard stock solution (3.7) and dilute it step by step with 20% ethyl acetate methanol solution (3.4) to a series of mixed standard working solutions of 0.1mg/L~10.0mg/L for later use.
4 Instruments and equipment
4.1 Gas chromatograph-mass spectrometer (GC-MS): equipped with electron impact ionization source (EI source).
4.2 Vortex oscillator.
4.3 Ultrasonic cleaner.
GB/T 35894-2018 The following standards are cited：
