A method was developed for the simultaneous trace analysis of linear alkylbenzene sulfonate(LAS) and their biodegradation intermediates, sulfophenyl carboxylates (SPC), in sewage effluent and river water. Sensitive determination using a liquid chromatograph equipped with a tandem mass spectrometer (LC-MS/MS) following solid-phase extraction was employed. The analytical method was applied to study the behavior of LAS and SPC during sewage treatment. SPC concentration (sum of C₅-C₁₃ SPC: 80μg·l^-1) in secondary effluent was 2.5 times higher than that in raw sewage (30μg·l^-1), whereas very high levels of removal (99.2%) of LAS (sum of C₁₀-C₁₄ LAS) was observed during the secondary treatments. This suggests the formation of SPC by biodegradation of LAS during sewage treatment. Broad-spectrum monitoring of synthetic-detergent-derived compounds including LAS, SPC and fluorescent whitening agents (FWAs; DSBP and DAS1) was conducted for 20 representative Japanese rivers. LAS, SPC, and FWAs were widely distributed in the river water at concentrations in the range of 0.2-63μg·l^-1, 0.02-68μg·l^-1, and 0.013-4.55μg·l^-1, respectively. Higher concentrations of the detergent-derived pollutants were observed in urban rivers which have larger populations in their catchment areas. In many rivers, SPC concentrations were higher than those of LAS, suggesting that SPC should be considered in the risk assessment of LAS.