This review provides an overview and discusses different analytical strategies that minimize or eliminate the preparation of samples for speciation of organic and inorganic species of As, Cr and Se in samples of biological interest. These metals are important for the human body and the presence of various chemical forms of metals determines its essentiality and toxicity, thus speciation comes as an important tool for the study of biological samples. However, speciation requires a reduction in the steps of sample preparation, allowing a sample investigation in its most native form in order to reduce the changes in chemical species. The strategies proposed for speciation of these metals include: solid phase extraction, point cloud extraction, suspension and direct analysis. Selected methods proposed for the speciation of organic and inorganic species of As, Cr and Se were reviewed including their main figures of merit, advantages and disadvantages
The paper presents the principles and advantages of a technique combining high performance liquid chromatography and hydride generation atomic absorption spectrometry (HPLC-HGAAS) applied to speciation analysis of inorganic species of arsenic As(III) and As(V) in ground water samples. With separation of the arsenic species on an ion-exchange column in the chromatographic system and their detection by the hydride generation atomic absorption spectrometry, the separation of the analytical signals of the arsenic species was excellent at the limits of determination of 1.5 ng/ml As(III) and 2.2 ng/ml As(V) and RSD of 4.3% and 7.8% for the concentration of 25 ng/ml. The hyphenated technique has been applied for determination of arsenic in polluted ground water in the course of the study on migration of micropollutants. For total arsenic concentration two independent methods: HGICP-OES and HGAAS were used for comparison of results of real samples analysis.