The toxicity and biological activity of an element may vary considerably with its chemical form, for example, variation in oxidation state: chromium VI versus chromium III or variation in molecular or complexation state: methyl mercury versus inorganic mercury. It is important, therefore, to measure individual elemental “forms” or species rather than just the total concentration. These measurements are required to understand the environmental, biomedical, epidemiological, and toxicological impact of these trace elements.
Over the past 20 years, RTI International has conducted speciation studies for various elements, including, but not limited to: arsenic, chromium, mercury, nickel and tin. Some of the analytical methods developed and/or utilized in characterizing the individual species associated which each element, in various sample media, will be discussed. Often, a sample preparation technique is first employed, which isolates and preserves the integrity of individual elemental species. A chromatographic method to separate species is then typically employed, followed by detection of individual species by a spectrometric technique such as inductively coupled plasma - mass spectrometry (ICP-MS). Qualitative and quantitative elemental speciation data will be presented.
Back to Automation in the Chemical Lab-Analytical Methods-Environmental Chemistry (General Session)
Back to The 56th Southeast Regional Meeting 2004 (November 10-13, 2004)