Chemical analysis is being used as the main tool by a large number of businesses and for a wide range of everyday life fields. Those businesses rely their activities on chemical analysis results. Chemical analysis and subsequently quality control applies in different sectors of the environment, nutrition, bioanalysis and synthesis of materials. Aiming at quality control, toxicological studies or research activities. Many laboratories, more of them accredited and equipped with the appropriate and expensive instrumentation, develop and apply protocols adapted to the requirements of each application./p>
Due to the statutory legislation and the promotion of research activities, chemical analysis is an internationally significant sector around which immense financial capitals are channelled for the development and application of techniques and the development of new materials and services. In this framework this project aims at the synthesis of nanomaterials with features that will become fully exploitable in chemical analyses with applications in the environment, food, and bioanalysis.
A basic stage in chemical analysis is the preparation of the sample which basically requires the isolation of the analytes from the matrix and their reliable measurement using the appropriate instrumentation.
For liquid - aqueous samples the most usual preparation techniques are: solid phase extraction, solid phase micro-extraction, stir bar sorptive extraction and liquid - liquid extraction. Among them, the most widely used is the first one, due to the great variety of commercially available sorptive materials that cover a wide range of organic compounds with different physiochemical properties. The sorptive material rarely can be reused, while the presence of suspended solids causes clogging of the holding cartridge, the cost of which is rather high for many of the commercially available materials. Solid phase micro-extraction, even though doesn’t exhibit a variety of suitable materials, has conquered a great share of the market, due to the ease of usage and its smooth operation. It lacks in terms of cost (rather high even though the fibres are reusable), because the fibres are fragile. Regarding stir bar sorptive extraction, during the last few years it has proven to be a promising technique, but it has not conquered a share of the market due to inherent problems of the technique. The only commercially available extraction phase - material is polydimethylsiloxane, a non polar phase proper for extracting non polar to medium polar compounds. Finally, liquid - liquid extraction requires the use of great volumes of solvents, a fact that increases significantly the cost, while it is not friendly to the environment is one of the choice today.
The same techniques can be also applied for the detection of trace quantities to food samples, under certain conditions, with similar or even greater problems due to the matrix's complexity and the lack of liquid character. One of the techniques that are used is matrix solid phase in which the sample (solid) is homogenized with the extraction material and the mixture is applied in a cartridge where the extraction and cleanup of the sample are performed. The process is time-consuming, requires relatively great amounts of sorptive material and, due to the required supplementary extraction, the repeatability isn't always satisfying. Alternatively, for solid samples classical extraction is used with organic solvents, followed by the clean up of the extract with organic solvents of different polarity using sorptive materials with column chromatography.
t's obvious that any new technique that contributes to sample analysis, providing easiness of use, satisfying efficiency and low cost will earn a share in chemical analysis market for quality sensitive laboratories as well as for research centers that wish fast and reliable analyses. A wide range of compounds such as pesticides, steroids, pharmaceuticals, polychlorinated biphenyls, phenolic endocrine disruptors, toxins, xenobiotic compounds in biological systems etc. are some of the categories of compounds in the analysis of which the extraction and micro-extraction techniques apply.
Nano materials in Chemical Analysis
Reducing the size of magnetic materials in nano - scale has brought new prospects in the material science during the last few decades. Nano materials feature unique properties which are located between molecular and micro-scale or bigger materials. Nowadays these properties are applied in many sections of technological applications. Magnetic nano materials uniquely combine hypermagnetic behaviour with dimensions that approach analytes at molecular level.
The combination of magnetic nano particles with analytical techniques and analytical methods has opened new prospects in the fields of sensors, the cleanup of waste and aquifers, as well as in quantitative analytical chemistry. Low intensity magnetic fields can be used for the control of movement and properties of magnetic particles. In analytic chemistry the use of magnetic fields along with magnetic nanomaterials provide important tools for the management and the chemical analysis of chemical particles. A large number of magnetic nano materials is available today, in different forms, like dry powder, modified powder or stabilized aqueous or organic suspensions: Magemite (γ-Fe2Ο3), magnetite, (Fe3Ο4), cobalt ferrite, (CoFe2O4), manganzincferrite (MnZnFe2O4).
Modified magnetic nanomaterials are high-tech materials which, with the proper active chemical groups and improved natural properties, can be synthesized relatively easily and economically offering desirable chemical properties. In this context, for the production of the core - shell nanoparticles the magnetic nanomaterials can be covered surficial, with a few nanometres of an organic or inorganic layer.
Today's chemical analysis practices do not use nanomaterials not to mention the use of the magnetic nano materials.
The use of these materials in the analytical and research field will led to new prospects in chemistry and analysis. In relation to the current situation, it will help in reducing the analysis cost as well as the required time and consumables for the preparation of the samples. It will allow the reduction of the limits of detection and quantitation of substances that are considered dangerous for the human health and/or the environment. It will help in the general financial growth in all industrial sectors, in health services and in research. The faster evaluation of the analysis results will give the industry the opportunity to deal faster with problems in the production, by taking immediate corrective actions in the production line. Thus, waste of raw materials and non conforming products be reduced. Problems with the authorities or with consumers due to the presence of non satisfactory products in the market will also be avoided. The scientific community will have a tool available that will give additional help for the implementation of new scientific accomplishments and the analytical laboratories especially will acquire useful materials for helping into the implementation of all the above.