Long pathlength absorbance spectroscopy: trace analysis of Fe(II) using a 4.5 m liquid core waveguide

A Liquid Core Waveguide (LCW) can be used to extend the sensitivity of conventional absorbance spectroscopy by two or more orders of magnitude. Analysis of dissolved iron concentrations with a 4.47 m pathlength LCW made of Teflon AF-2400 provides a 0.2 nmol dm−3 detection limit and a linear response between 0.5 and 10 nmol dm−3. No preconcentration is required in this analysis. The analytical procedures employed in long pathlength absorbance spectroscopy are amenable to miniaturization and autonomous operation.