High-performance flow atomic spectrometry permits the fully automated separation of Cr(III)/Cr(VI) species and subsequent flame AAS determination within only 1 min. An HPLC integrator at the output of the flame AA spectrometer renders possible the simultaneous signal processing of both oxidation states. Samples of drinking water, waste water, and extracts of soils were investigated. The relevant detection limits are 0.03 Cr(III) or 0.02 μg/mL Cr(VI) (3σ values, N = 25). The relative standard deviation amounts to ∼1% (N= 10,1 μg/mL). With the same type of chromium speciation column (modified CI8 type), Cr(VI) can be preconcentrated from drinking water and then determined online by flame AAS within 3.5 min. A detection limit of 0.5 μg/L (3σvalue) can be attained when a sample volume of 5 mL is used; the standard deviation is 3.1 (10 μg/L Cr(VI)) or 1.5% (100 μg/L Cr(VI)).
ASJC Scopus subject areas
- Analytical Chemistry