GB/T 35946-2018 in English

GB/T 35946—2018 Standard Interpretation

GB/T 35946—2018 "High Performance Liquid Chromatography Method for the Determination of Thimerosal in Eye Cosmetics" is an important national standard for the detection of thimerosal in eye cosmetics in China, and is applicable to a variety of eye products including makeup removers, eye shadows, eye creams, etc.

Background of Standard Formulation

With the development of the cosmetics industry, consumers are increasingly concerned about the safety and ingredients of products. Thimerosal, as a commonly used preservative, is widely used in various cosmetics, but due to its potential toxicity, it is crucial to strictly control its content. The formulation of this standard aims to ensure the safety of eye cosmetics and protect the health of consumers.

Technology Evolution Analysis

High Performance Liquid Chromatography (HPLC) is currently one of the most accurate and sensitive detection methods. Compared with traditional spectrophotometry, HPLC has significant advantages in separation efficiency and detection limit, and is particularly suitable for quantitative analysis of trace components.

Instrument and equipment requirements

According to the standard, the main instruments used include:>High Performance Liquid Chromatography (HPLC), Ultrasonic Cleaner, Solid Phase Extraction Device, etc. Among them, the configuration of HPLC must meet the requirements of the diode array detector.

Sample Preparation and Cleanup Steps

1. Extraction:Solid or semi-solid samples are dissolved in 50% methanol solution, and liquid samples are directly diluted.
2. Centrifugation:High-speed centrifugation (6000 r/min) is used to separate the supernatant.
3. Purification:Use a solid phase extraction column of specific specifications for elution and washing to remove impurities and collect effective components.

HPLC determination steps

• Mobile phase configuration:0.05 mol/L ammonium acetate and methanol in a volume ratio of 60:40.
• Column temperature and flow rate:Maintain the column temperature at 35°C and set the flow rate to 1.0 mL/min.
• Detection wavelength:Select 240 nm for detection.

Result calculation and allowable difference

Calculate the thimerosal content according to the formula and retain two decimal places. The absolute difference between two independent determinations shall not exceed 10% of the arithmetic mean.

Standard implementation recommendations

1. Training:Provide professional training on HPLC operation and data analysis to relevant personnel to ensure accurate detection.
2. Equipment maintenance: Regularly calibrate the instrument to ensure its stable performance.
3. Quality control: Establish a complete quality control system, including blank test and standard curve drawing.