Enrichment and Preservation of Urine Metabolites Using Styrene Divinylbenzene Reversed Phase Sulfonate (SDB-RPS)...

Urine metabolomics plays a crucial role in biomarker discovery and disease monitoring, but challenges in metabolite preservation remain. This study evaluates the use of styrene divinylbenzene reversed phase sulfonate (SDB-RPS) disks for enriching and preserving urine metabolites utilizing ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) for analysis. We compared SDB-RPS-enriched urine samples with untreated urine across three experimental parts: (1) metabolic profiling using C18 and HILIC chromatography under both positive and negative ion modes; (2) degradation kinetics, where SDB-RPS and untreated urine samples were incubated at 55, 65, and 75 °C with constant humidity (75%); and (3) disease classification using hepatitis (n = 72) and cirrhosis (n = 72) samples. The results revealed that metabolite identification was highly consistent between SDB-RPS and urine samples, with an overlapping rate of 88.26%. Additionally, in the disease classification task, the SDB-RPS panel demonstrated consistent performance, with AUC values of 0.867 and 0.828 in training and validation data sets, respectively, outperforming the urine panel (AUC: 0.765 and 0.691, respectively). These findings suggest that SDB-RPS disks significantly enhance the enrichment and long-term preservation of urine metabolites, offering a promising tool for clinical sample analysis and biomarker discovery.