Detection of Anionic Nutrients by SERS of Cationic-Coated Silver Substrates. Effect of Chloride Ion

Earlier it was demonstrated that surface-enhanced Raman spectroscopy (SERS) of cationic-coated silver substrates could successfully detect nitrate and sulfate in the parts-per-billion to parts-permillion concentration range. However, these cationic coatings also interact with chloride ion. In this paper, the magnitude of the chloride ion interference is examined. To eliminate the interference, we explore the use of selective ionophores and solid-phase extraction (SPE).