Chitosan (CTS) modified magnetic nanoparticles (CTS@Fe3O4 MNPs) offer dual functions for the detection of surfactants using surface enhanced laser desorption/ionization mass spectrometry (SELDI-MS). The characterization of CTS@Fe3O4 MNPs is carried out using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and UV-vis absorption. CTS@Fe3O4 magnetic nanoparticles offer a simple separation method for surfactants. CTS@Fe3O4 MNPs show an absorption band at 337 nm that matches the laser wavelength of the N2 laser. The material provides dual functionalities; as a probe and for surface enhanced LDI-MS. Analysis of surfactants using CTS@Fe3O4 MNPs shows a remarkable limit of detection, offers high throughput analysis and fast separation (<5 min). Compared to a conventional organic matrix (2,5-DHB), the spectra obtained using CTS@Fe3O4 MNPs …