Advantages And Disadvantages Of Co-Precipitation

Advantages And Disadvantages Of Co-Precipitation

Co–precipitation Co–precipitation is an important technique widely used for separation and pre–concentration of analytes from various samples [examples]. It is adopted when direct precipitation cannot separate the desired metal ions due to their low concentrations in the sample (Bulut VN et al. 2008). Various mechanisms including surface adsorption, ion exchange, surface precipitation and occlusion are involved in co–precipitation technique [ ]. Metals, at trace levels, react with an organic or inorganic compound forming a solid phase. The major precipitate then reacts with other metals to form chelates. Finally, solid particles are separated from the aqueous media and re–dissolved in acid or in an organic solvent (Komjarova I 2 et al. 2006; ... Show more content on Helpwriting.net ...By use of partitioning between an organic and an aqueous phase, an analyte can be separated from an interfering matrix. Liquid–liquid extraction involves two steps; complex formation with the dissolved extractant in the aqueous phase and the transfer o f the complex from the aqueous into the organic phase. LLE has some advantages such as simplicity and ease of operation. However, this approach presents several drawbacks and limitations like consumption of large amounts of hazardous organic solvents and sample volumes, limited enrichment factors, time consumption and the formation of stable emulsion at the interface of the two phases. In addition, the generation of large amounts of pollutants makes this procedure tedious, expensive and environmentally unfriendly. Therefore, alternative unconventional LLE methodologies such as: dispersive liquid–liquid microextraction (DLLME), dispersive liquid–liquid microextraction based on solidification of a floating organic drop (DLLME–SFO), homogeneous liquid–liquid extraction (HLLE) single drop microextraction (SDME) and cloud point extraction (CPE) have been introduced and developed to address the limitations in the LLE .( Recent development and applications of dispersive liquid–liquid microextraction, Recent developments in homogeneous and dispersive liquid–liquid extraction for inorganic elements determination. A

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