High-performance flow flame atomic absorption spectrometry for automated on-line separation and determination of chromium(III)/chromium(VI) and preconcentration of chromium(VI)

Abstract

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 Mg/mL Cr(VI) (3 values, N = 25). The relative standard deviation amounts to ~1% (N= 10,1 Mg/ mL). With the same type of chromium speciation column (modified CIS 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 Mg/L (3 value) can be attained when a sample volume of 5 mL is used; the standard deviation is 3.1 (10 Mg/L Cr(VI)) or 1.5% (100 Mg/L Cr(VI)).

On-line preconcentration using dual mini-columns for the speciation of chromium(III) and chromium(VI) and its application to water samples as studied by inductively coupled plasma-atomic emission spectrometry

“…Liquid chromatography (LC) is a convenient method for the separation and determination of metal ions simultaneously. The LC methods coupled with atomic absorption spectrometry (LC-AAS) [5], inductively coupled plasma atomic emission spectrometry (LC-ICP-AES) [6], and inductively coupled plasma mass spectrometry (LC-ICP-MS) [7] were successfully applied to the speciation of chromium in water samples. Generally, the speciation of chromium is performed after the separation of one species of chromium (III) and (VI) by sorption [8][9][10], solvent extraction [11], and co-precipitation [12,13], followed by the instrumental analysis, and the another species is then determined after reducing or oxidizing the residual chromium contained in the sample solutions.…”

Többcsatornás mikrofluidikai rendszerek fejlesztése kromatográfiás alkalmazásokhoz

“…Az elválasztás/dúsítás során az irodalomból ismert körülményeket alkalmaztuk. 18 20 Az FAAS készülék mikrofluidikai csipekhez való kapcsolása mellett megvizsgáltuk a lézerindukált plazma spektrométer detektorként való használatát, melynek nagy elõnye a mikrocsip és a LIBS készülék közötti kapcsolat kialakításának egyszerûsége. A LIBS mérések során nagyenergiájú lézer sugárral lõttük meg a mikrocsipet.…”

Effect of organic Cr(III) complexes on chromium speciation

“…Coupled methods combining liquid chromatography with AAS detection, atomic emission spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and visible spectrometry have been developed (Posta et al, 1993;Li et al, 1996;Byrdy et al, 1995;Padarauskas et al, 1998). Ion chromatography, reversed-phase liquid chromatography and ion-pairing chromatography are applied as chromatographic methods (Poboz'y et al, 1996;Padarauskas et al, 1998).…”