Environmental applications of liquid-waveguide-capillary cells coupled with spectroscopic detection

Long path-length liquid-waveguide-capillary cells (LWCCs) comprise a capillary with a refractive index (RI) lower than the RI of the liquid core. This enables light introduced into the capillary core to be totally internally reflected down the capillary towards the detector, resulting in an enhancement of sensitivity and improved limits of detection compared with conventional spectroscopic techniques. LWCCs are also versatile and have been used in combination with spectrophotometry, Raman spectroscopy and luminescence detection for quantification of a range of chemical species at nanomolar concentrations.This article describes the properties and the practical aspects of LWCC instrumentation and applications to environmental matrices. We also present summary tables of applications, including figures of merit, LWCC properties and technical details.