Analytical Inorganic Chemist

Department of Biochemistry
Medical Sciences Campus
University of Puerto Rico

Research Interest:Environmental Inorganic Chemistry:

Working with the Center for Environmental and Toxicological Research in the area of inorganic chemistry particularly with trace elements and their effects in the environment. Interested in the effects of metal speciation in living organism.

Living organisms require trace amounts of certain heavy metals, but excessive levels can be detrimental to the welfare of organisms. Some heavy metals have no known vital or beneficial effect in organisms, and their accumulation over time can cause serious problems and illnesses. Determining the total concentration of specific heavy metals gives no information on the particular form it accumulates in organisms. One of the most crucial properties of these heavy metals, which differentiate them from other toxic pollutants, is that they are not biodegradable in the environment. The determination and monitoring of specific chemical forms of the heavy metals in environmental samples such as airborne particulates, waters, biological materials, soils or sediments are extremely important in order to understand the pathways, cycle and hence its possible toxicity. The development of analytical techniques to reliably measure the concentrations of the various chemical forms (speciation) of trace metals in an environmental sample is one of the most challenging problems that face environmental chemists.

Our research group uses established techniques for determining heavy metals in various matrices such as; crustacean, fish, fresh, sea water and sediments. Some of the techniques used are graphite furnace atomic absorption, capillary electrophoresis and high performance liquid chromatography. Of particular interest for our group is the speciation of arsenic compounds in the environment. These compounds have received considerable attention due to As toxicity. It is know that organic arsenic compounds are less toxic that their inorganic counterparts and that living organism change inorganic arsenics compounds to organic form by their metabolism. Of particular interest are, arsenous acid, As(OH)3, arsenic acid, H3AsO4, monomethylarsonic acid, CH3As(OH)2 dimethylarsinic acid, (CH3)2AsO(OH), arsenobetaine, (CH3)3As+CH2COO-, and arsenocholine, (CH3)3As+CH2CH2O-. What is the relative importance and prevalence of these compounds in the Puerto Rican environment yet needs to be determined.