Liquid-Phase Behavior of Mono and Triligand of Elemental Centers with Bidentate Hydrazide-Containing Ligands and Proteinogenic Derivatives

<p>The distribution of an element among recognized chemical species in a system is known as chemical speciation. The analytical procedure for identifying and measuring each distinct chemical species in a sample is called a speciation study. Without a doubt speciation studies1-4 are important in all areas of chemistry. The significance of this is particularly noticeable in the fields of biological and environmental chemistry since the bioavailability mobility and toxicological impact of a component are largely determined by its speciation. In naturally occurring aquatic habitats the activity of the specific metal species is responsible for the toxicity rather than the total concentration of the metal as is widely recognized. The majority of heavy metals are harmful to life when they enter the human body in various ways while some other metal ions are thought to be necessary but can become hazardous when detected in excess in the body. Most of these toxic effects are highly dependent on the specific form of the element in the biological fluids. These many chemical configurations of an element or its derivatives are frequently referred to as species. In IUPAC Recommendations 2000 the word chemical species was defined 5 as a specific form of an element defined as to isotopic composition electronic or oxidation state and/or complex or molecular structure. Every time a new system is studied a different collection of species may be seen because the composition temperature and ionic strength of natural systems vary widely all of which have an impact on the composition and quantity of formation of the species.</p>