Speciation of Chromium in Water Samples after Dispersive Liquid-Liquid Microextraction, and Detection by Means of High-Resolution Continuum Source Atomic Absorption Spectrometry

Abstract

A newly analytical method has been developed to determine total chromium and speciation of this element in water samples through dispersive liquid-liquid microextraction combined with a high-resolution continuum source flame atomic absorption spectrometry. The most significant variables affecting complexation and extraction were optimized by using response surface methodology and univariate optimization. The best conditions for both the complexation and extraction elements in this study were: complexing agent ammonium pyrrolidine dithiocarbamate (APDC 6.0 mmol L ) and 19 for total Cr. The method accuracy was carried out by using certified water reference material (NIST CRM 1643e), and the results achieved were in agreement with the certified value (t-test at a confidence interval of 95%). The method developed was applied in samples of mineral water, tap water (the recovery values ranged from 88 to 115%) and seawater.

Green sample preparation strategies for organic/inorganic compounds in environmental samples

“…Ammonium pyrrolidine dithiocarbamate was introduced for Cr (VI) retention at pH 2.0. Reduced volumes of 1-undecanol and ethanol and non-chloride solvents were used for the non-polar phase [61]. As mentioned before TXRF represents advantages for Green Chemistry since no eluents and carrier gases are needed.…”

Combination of Dispersive Liquid–Liquid Microextraction and Emulsion Breaking for the Determination of Cu(II) and Pb(II) in Biodiesel and Oil Samples

“…In spite of some advancements in analytical instrumentation, metals in low concentrations, such as Cu­(II) and Pb­(II), for example, in complex matrixes, such as oil and biodiesel, require separation and preconcentration steps before detection. In this paper we report, for the first time, the use of dispersive liquid–liquid microextraction (DLLME) − combined with emulsion breaking for determining Cu­(II) and Pb­(II) in oil and biodiesel samples. Reverse dispersive liquid–liquid microextraction was used by López-García et al for the determination of Cd and Pb and arsenic species in edible oils.…”