GB/T 35771-2017 in English

Background and Significance of the Standardization

GB/T 35771—2017 was proposed and managed by the National Technical Committee for Standardization of Key Product Inspection Methods for Quality Supervision, and is applicable to the qualitative and quantitative determination of dimethyl sulfate and diethyl sulfate in water-based, emulsion, cream and other cosmetics. The formulation of this standard provides a scientific basis for the safety testing of cosmetics and ensures that product quality meets the requirements of national standards.

Technical Methods and Principles

This standard adopts gas chromatography-mass spectrometry (GC-MS) combined with selected ion monitoring mode (SIM), and uses retention time and abundance ratio of characteristic selected ions for qualitative analysis, and external standard method for quantitative analysis. This method has the advantages of high sensitivity and strong specificity.

Reagents and Instruments

The main reagents required for the experiment include: methanol, tetrahydrofuran, ethyl acetate, etc. The standard substances are dimethyl sulfate and diethyl sulfate, with a purity greater than 98%. The main instruments are gas chromatography-mass spectrometer (GC-MS), equipped with an electron impact source (EI), and the injection port temperature is 250℃.

Detailed explanation of test steps

Sample treatment:Different extraction methods are used for different types of cosmetics, such as adding ethyl acetate and anhydrous sodium sulfate to water-based and emulsion cosmetics, vortexing and centrifuging to obtain the clear liquid for determination. For powder cosmetics, methanol is used for extraction.

Qualitative and quantitative analysis:GC-MS is used to determine the selected ion chromatographic peaks of the sample solution and the standard working solution to determine whether they appear at the same retention time, and the maximum deviation is allowed to be within the range specified in Table 1. Quantitative analysis uses the external standard method to establish a calibration curve.

Implementation suggestions and precautions

In actual testing, the standard requirements should be strictly followed to ensure the accuracy of reagents and instruments. For high-concentration samples, appropriate dilution is required before measurement to ensure accurate and reliable results. Blank tests and parallel tests are important means to verify data reliability and should be taken seriously.