Nanofiltrace

Nanofiltrace is a term encountered in niche discussions of analytical chemistry and membrane technology to describe a conceptual approach that combines nanofiltration with trace analysis to isolate and quantify minute levels of target compounds. It is not a widely standardized method, and definitions may vary between sources.

In typical implementations, a sample is processed through a nanofiltration membrane with a molecular weight cutoff in the range of about 200 to 1000 Da. The membrane concentrates the analyte while reducing interferents, and the retentate or permeate is then analyzed by a sensitive detector such as LC-MS, ICP-MS, fluorescence, or UV-Vis spectroscopy. The approach can be used online in flow systems or offline with batch processing. Throughput and concentration factors depend on membrane properties, sample matrix, and operating conditions.

Applications include trace-level analysis of pharmaceuticals, pesticides, and metals in water, environmental samples, food and beverages, and some biological fluids.

Advantages include pre-concentration, reduced solvent use, and compatibility with aqueous matrices. Limitations encompass membrane fouling, and variability in selectivity and retention with changes in pH, ionic strength, and matrix composition, as well as potential analyte loss and the need for method validation. Not all analytes are suitable for this approach.

Outlook: as a concept, nanofiltrace may evolve with advances in membrane materials and online detection, but it remains one of several niche approaches to trace analysis rather than a universal standard.