**2. Separation and enrichment methods**

Separation of a substance between two phases in contact with varying proportions of distribution basis. In all separation methods solid-liquid, liquid-liquid, liquid-gas and solid-gas, there are two phases in the form. Trace element analysis generally has three separate applications of separation methods. These;


The first application is not used in the work analysis. Because the main component can be dragged along with trace elements. The other two applications are used more in work analysis. The trace elements are separated from the disturbing media components by enrichment methods. It is taken into smaller volume and concentrated. Two important criteria are used in the evaluation of enrichment methods.

*Trace Metals in the Environment - New Approaches and Recent Advances*

metal oxides, activated carbon, hydrogel polymers, ion exchange resins, and polymeric fibers, microspheres and natural polymers have been used in the literature as adsorbents to remove heavy metals from the aqueous environment. But, the adsorption capacity of some of these adsorbents is very low or a long time is necessary for the adsorption equilibrium. Some adsorbents are also difficult to revive and cannot be reused. Polymer resins with different functional groups and large surface area are broadly used for the separation of metal ions and enrichment of trace elements [3, 4]. Recently, the importance of removing heavy metal ions from aqueous media has been increasing for the purpose of control environmental pollution. Heavy metals in waste water may be removed by adsorption on solid materials. Different adsorbents such as metal oxides, activated carbon, peanut and rice shell, cotton, wool, chitosan, starch, sporopollen and wood shavings [5–14] are used as adsorbents in the removal of heavy metals from the aqueous environment. But, the adsorption capacity of some of these adsorbents is very low or they are broadly used in complexing with them. Recently, copolymer resin with functional groups have been used to remove heavy metal ions from waste waters. In the removal of heavy metal ions from aqueous media and enrichment of trace elements, the use of polymeric adsorbents with high adsorption rates and large surface area is increasing [15–20]. In a very short time, it is cited that the polymers of amidoxime group will find broad usage area as adsorbent in the recovery of uranium from ground water and sea [21–27]. The characteristics of the adsorbent, such as sorption capacity, selectivity to analyte, resistance to physical/chemical conditions, pH range, ease of availability, reusability and cost, are thought. In order to, new sorbents are continuously being examined and these features are expected to be advanced except in the

In the removal of heavy metal ions from aqueous media, functional groups such as ester, pyridine, amide, carboxylic acid, amidoxime and hydroxyl at the surface of the adsorbent are substantially effective. Adsorption of heavy metals from aqueous environmental can generally be controlled by functional groups on the adsorbent surface. Polymeric adsorbents containing N-methyl hydroxamic acid groups and amidoxime groups have been selectively used against some trivalent lanthanide metal ions [Nd(III), La(III), Gd(III), Sm(III), Tb(III)] and especially

The concentration range cited as edil "work concentration" it has changed over time in parallel with the improvements in artifact analysis techniques. Before 1940s,

in the 1965s work is cited as skin. Kaiser suggested the systematic approach and first naming. Kaiser gave the explanation of ppm and ppb. According to today's general

Recently, the most important parts of analytical chemistry, trace element analysis, soil, water and air pollution, such as pollution effects on the environment, such as the increasing importance of environmental issues, the elements of the human body and metabolism effects, the study of the chemical forms of the heavy metals in natural waters and determination of it has gained importance as the functions in many different areas are. The phrase trace element analysis is used for the determination of very small quantities of elements in the medium formed of large quantities of components. These environments can be minerals, metals, water, compounds, aqueous solutions, biological and organic substances. Often, the environment in which the trace element is available has a reverse effect on the determination. In such environments, accuracy and sufficient precision can not be obtained. The matter starts at the sampling phase in the study analysis. Especially, there may be a non-homogeneous trace element

% concentration range, and concentrations below10<sup>−</sup><sup>6</sup>

–10<sup>−</sup><sup>5</sup>

% in the 1950s and 10<sup>−</sup><sup>6</sup>

–10<sup>−</sup><sup>8</sup> %

are known

% of work sheets, 10<sup>−</sup><sup>3</sup>

**66**

literature [28, 29].

uranium ions.

–10<sup>−</sup><sup>2</sup>

usage, 10<sup>−</sup><sup>2</sup>

as ultra works.

%, rarely 10<sup>−</sup><sup>3</sup>

–10<sup>−</sup><sup>6</sup>

10<sup>−</sup><sup>1</sup>

The first one is the recovery efficiency. However, it is not always possible to achieve a large recovery value. At low concentrations, 90 or 95% recovery efficiencies are sufficient. The second term is the enrichment coefficient.

The enrichment methods in the work analysis undertake important functions. With enrichment techniques;


The following criteria should be taken into account when selecting trace element enrichment methods;

