Represented in this paper are the results of investigations aimed at checking up the capabilities of devices based on the surface plasmon resonance (SPR) phenomenon to be applied for studying the properties of water suspensions. As an example, the authors used here the suspensions of tooth pastes Sensodyne and Colgate in distilled water. For measurements, we used the SPR device Plasmon-71 operating in the near infrared spectral range. Results of these measurements were compared to those obtained using the spectrophotometric ones. The measured values of the sedimentation velocity obtained using both the applied methods confirmed availability to efficiently apply SPR devices for studying the opaque multi-component suspensions.