Pretreatment, Analysis, Identification and Preparation of Toxic Compounds Eluted into Body Fluids from Medical and Dental Devices

Selective analysis of toxic compounds in complicated matrix such as body fluids is extremely difficult. This is because unexpected interference admixtures with almost identical retention time in chromatography may co-elute with overlapping. 1t is essential to remove admixtures byappropriate pretreatment procedures. For that purpose there may be several sorts of pretreatment methods such as liquid-liquid extraction or solid phase extraction (SPE) using column, membrane dialysis filtration ultra-filtration super fluid critical extraction SFE or adsorption using charcoal or other appropriate adsorbents. It has been reported several pretreatment methods for acidic, basic and neutral compounds in biological fluids. Body fluids direct injection column is also available in the market, however this column has restriction of concentration of organic solvent in the eluent up to 20% of methanol (18% of acetonitrile), thus resulting in poor or no elution of strongly hydrophobic compounds on reverse phase. The reason of restriction is prevention of coagulation of denaturated protein in the reversed phase column. Artifact formation must also be considered during pretreatment methods. Artifact formation may cause lower recovery of the compound of interest and may also cause misunderstanding to the researcher, which they may extract unexpected highly strong toxic compound. According to the recent advancement of analytical column fabrication technology, several new columns based on innovated technology are now commercially available. Some of them can be resulted in incompletely residual silanol column, so common ion addition is required for strongly basic or acidic compounds analysis or ion-pair method is required. Ion-pair method is so popular but it often causes to shorten column life by retaining and spoiling the column with ion paring reagent. These columns are also described by comparing conventional columns in this paper.