1. GB/T 44998-2024 "Determination of Nitrate and Nitrite in Surfactants by Ion Chromatography":
- Scope of Application and Importance: This standard specifies a method for determining the residual amounts of nitrate and nitrite in surfactants using ion chromatography. Nitrate and nitrite may be present as impurities or by-products in surfactant raw materials or finished products, and excessive residues may affect product safety or stability. This method provides a unified and standardized technical basis for monitoring and improving the purity of surfactants.
- Principle of the method: Ion chromatography is a highly efficient technique for separating and detecting ions. After appropriate pretreatment, the sample is injected into the chromatograph, where the mobile phase carries the target nitrate and nitrite ions into the separation column for isolation. These ions are then qualitatively and quantitatively analyzed using a detector, such as a conductivity detector. This method offers advantages such as high sensitivity, excellent selectivity, and the ability to simultaneously analyze multiple ions.
2. GB/T 45000-2024 "Surfactant Composition Analysis of Sucrose Fatty Acid Esters by Liquid Chromatography":
- Scope of Application and Importance: Sucrose fatty acid esters (sucrose esters) are safe, non-toxic, and biodegradable nonionic surfactants widely used in the food, cosmetics, and pharmaceutical industries. Their performance is closely related to their composition (the proportions of monoesters, diesters, triesters, and polyesters). This standard employs liquid chromatography for the precise analysis of the various components of sucrose esters.
- Principle of the method: High Performance Liquid Chromatography (HPLC) separation is achieved by exploiting the differences in the distribution coefficients of various components between the stationary and mobile phases. For sucrose esters, by selecting appropriate chromatographic columns and detection conditions, components with different degrees of esterification can be effectively separated, and their relative contents can be calculated. This provides critical data for product quality control and application research.
The issuance and implementation of these national standards mark a further improvement in China's surfactant analysis and testing system. They provide authoritative and unified testing methods for manufacturers, quality inspection agencies, and R&D personnel, playing a crucial supporting role in ensuring the quality and safety of surfactants and their downstream products, promoting technical exchanges and fair trade, and guiding the industry toward high-quality and refined development.