Long pathlength absorbance spectroscopy: trace copper analysis using a 4.4 m liquid core waveguide

Procedures are described for measurement of dissolved copper with long pathlength Teflon AF-2400 liquid core waveguides. Using a 4.4 in waveguide, absorbance versus concentration is linear for copper concentrations between 1 and 160 nM. The molar absorbance of copper complexed with bathocuproine disulfonate is nearly identical for pathlengths between 1 cm and 4.4 m. Our 4.4 in waveguide system provided a 0.4 nM detection limit with no sample preconcentration. The methods developed in this study have been used to determine copper concentrations in natural seawater, river water, and commercial drinking water. (C) 2002 Elsevier Science B.V. All rights reserved.