GB/T 35953-2018 (English Version)

Standard No.: GB/T 35953-2018
Language: Chinese, English version preview
Release Date: 2018
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 35953-2018

Scope: This standard specifies the reagents and materials, instruments and equipment, analysis steps, result calculation, recovery rate and precision, and permissions for the headspace gas chromatography determination method for methylene chloride and 1,1,1-trichloroethane in cosmetics. Poor content. This standard is applicable to the determination of methylene chloride and 1,1,1-trichloroethane in creams, lotions, liquids and water cosmetics. The detection limits of this standard for dichloromethane and 1,1,1-trichloroethane are 0.070mg/kg and 0.0010mg/kg respectively, and the quantitation limits are 0.25mg/kg and 0.0050mg/kg respectively.

Introduction

1. Scope and applicability of the standard

This standard is applicable to the determination of dichloromethane and 1,1,1-trichloroethane in creams, lotions and water-based cosmetics.

Compound Name	Detection Limit(mg/kg)	Quantification Limit(mg/kg)	Analysis Method
Dichloromethane	0.070 mg/kg	0.25 mg/kg	Gas Chromatography
1,1,1-Trichloroethane	0.0010 mg/kg	0.005 0 mg/kg	Gas Chromatography

2. Background of Standard Formulation and Analysis of Technology Evolution

With the development of the cosmetics industry, the safety of restricted substances has received increasing attention. Dichloromethane and 1,1,1-trichloroethane are potentially harmful substances, and their residual amounts in cosmetics must be strictly controlled. This standard is based on Gas Chromatography (GC) combined with an Electron Capture Detector (ECD), ensuring high sensitivity and accuracy of the measurement results.

3. Experimental Principles and Methods

3.1 Principle

The sample is placed in a sealed headspace injection bottle. Under a certain temperature and time balance, the target compound reaches a dynamic equilibrium in the gas-liquid phase. By measuring the concentration in the gas phase and combining it with the sample mass, the specific content in the sample is calculated.

3.2 Reagents and Instruments

Gas Chromatograph: Equipped with Electron Capture Detector (ECD)
Headspace Sampler: 20 mL Headspace Sampler Bottle
Analytical Balance: Sensitivity of 0.01 g and 0.1 mg
Volume Flasks: 10 mL, 50 mL and 100 mL

4. Implementation Suggestions

Strictly follow the standard operating procedures for sample pretreatment to ensure weighing accuracy.
Regularly calibrate the instruments, especially the sensitivity of the gas chromatograph and electron capture detector.
Establish a quality control system, including blank test and recovery verification, to ensure data reliability.
For high-risk products (such as cosmetics containing volatile ingredients), it is recommended to increase the frequency of testing.

GB/T 35953-2018 Referenced Document

GB/T 6682 Water for analytical laboratory use.Specification and test methods

GB/T 35953-2018 history

2018 GB/T 35953-2018 Determination of restricted dichloromethane and 1,1,1-trichloroethane in cosmetics—Headspace gas chromatography