Extraction Method

EXTRACTION METHOD

Extraction

  • Toxicants to be detected are usually found embedded in difficult matrices such as blood, tissues,feed, fodder etc. Toxicants in liquid media are usually easier to extract than those in solid media. It is usually difficult to generalize the method of extraction to be adopted since every medium or every toxicant may require different extraction protocols. Extraction helps in mixing or dissolving the toxicant in the solvent for further analysis. Some of the extraction procedures commonly adopted are discussed .

Blending

  • Electrically operated blender and sonicator can be used to separate samples from cell and subcellular organelles respectively. Differential centrifugation can be done after blending for extraction of fraction of interest.

Washing and shaking

  • Washing or shaking of samples will release surface contaminants in the solvent used for washing.

Continuous Extraction

  • Soxhlet continuous extraction apparatus can be used for an exhaustive extraction of the toxicants from the sample of interest.

Homogenization

  • Homogenization is intensive blending of mutually related substances or groups of mutually related substances to form a constant different insoluble phases (sometimes with addition of surfactants) to obtain a suspension or emulsion.

Liquid -liquid extraction

  • Liquid-liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. It is an extraction of a substance from one liquid phase into another liquid phase.

Solid extraction

  • It is a separation process by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue

Cold extraction

  • Cold extraction is  a process whereby a substance is extracted from a mixture via cold water . It is a type of fractional crystallization.  
Last modified: Sunday, 25 September 2011, 9:53 AM