Flow injection thermal lens spectrometric detection of hexavalent chromium
School of Environmental Sciences, University of Nova Gorica, P.O. Box 301, Vipavska 13, Nova Gorica, Slovenia
2 Departamento de Física, Universidade Estadual de Maringá, 87020-900 Maringá, PR, Brazil
Corresponding author: firstname.lastname@example.org
A new highly sensitive flow-injection analysis (FIA) method with thermal lens spectrometric detection (TLS) was developed for determination of hexavalent chromium (Cr(VI)) in water. TLS measurements of Cr(VI) with diphenylcarbazide (DPC) method in a batch mode are subject to lower sensitivity and are less reproducible due to photodegradation of Cr-DPC complex during the measurement. In a FIA mode the decomposition of Cr-DPC induced by an intensive excitation laser source (140 mW at 514.5 nm) can be avoided or significantly reduced. For this purpose a FIA-TLS system was assembled and Cr(VI) determined by on-line generation of Cr(VI)-DPC. Under optimal conditions, a linear calibration graph was obtained for the range of Cr(VI) concentrations 1–20 μg/L. A LOD (limits of detection) value of 0.07 μg/L was achieved for Cr(VI) in water.
© EDP Sciences, Springer-Verlag, 2008