A filter membrane, also known as a membrane filter, is a thin film of polymer (plastic) with particularly fine micropores, made by solvent casting of certain types of polymers. Driven by external energy or chemical potential difference, the filter membrane allows particles or charged molecules smaller than the pore size to pass through the membrane pores, while the remainder is retained, thereby achieving the fractional separation, purification, and concentration of two- or multi-component mixtures.

A needle filter is a device used in pipelines for conveying media, primarily for filtering particulate contaminants from samples or media, sterilizing them, and protecting instruments and equipment. Its core functions include sample pretreatment before high-performance liquid chromatography (HPLC) and gas chromatography (GC) analysis, preventing particulate matter from clogging the chromatographic column and extending the instrument's lifespan.

Purge-and-trap is a dynamic headspace technique that uses flowing gas to "purge" volatile components from a sample, then uses a trap to adsorb the purged organic matter, followed by thermal desorption before sending the sample to a gas chromatograph for analysis. The purge-and-trap products provided by [Company Name] are widely used in environmental monitoring, food safety, and pharmaceutical fields.

Solid-phase extraction (SPE) is a sample pretreatment technique developed in recent years. It combines liquid-solid extraction columns and liquid chromatography, and is mainly used for sample separation, purification, and concentration. Compared with traditional liquid-liquid extraction methods, it can improve analyte recovery, more effectively separate analytes from interfering components, reduce sample pretreatment processes, and is simple, time-saving, and labor-saving. It is widely used in pharmaceuticals, food, environmental protection, commodity inspection, and chemical industries.