2Outline Extraction. Substance distribution between two liquids. The main quantitative characteristics of extraction.Types of extraction systems.The main organic reagents which use in extraction method.Usage of extraction in the drug analysis.
31. Extraction. Substance distribution between two liquids. Extraction – is the process by which a solute is transferred from one phase to a new phase.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.Аaq Аor
4Separatory funnel for use in a liquid–liquid extraction. Process of dissolved substance transferring from one phase to another phase, which are immiscible or restrictedly miscible, is named liquid-liquid –partition or partition between two phase of liquids.Separatory funnel for use in a liquid–liquid extraction.
5Two phase system, hydrophobic (top) and hydrophilic (bottom) for measuring the partition coefficient of compounds.
6Solid-phase extraction cartridges: (a) disk cartridge; (b) column cartridge.
7Partition law of Nernst – Shilov: The relationship of dissolved substance concentration in both phases at constant temperature is constant and does not depend on concentration of the dissolved substance:D = CAorg CAaquD – the distribution ratio remains constant if there are no processes:dissociation or associationpolymerisation or other transformations of the dissolved substance
8The ratio of substance activity in one certain form in organic solvent phase to its activity in a water phase is named a distribution constantThe distribution ratio and constant are connected with substance solubility
9Main concepts:Extraction is process of transferring substance of a water phase in organicExtraction reagent is reagent which with investigated substance forms compound which then is extractedExtragent is organic solvent which is used for extractionLatent solventExtract - is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol or water. Extracts may be sold as tinctures or in powder formRe-extraction is process of transferring substance of organic phase in waterRe-extragent
10Conditions of a choice of solvent which is used as extragent: 1. Should not mix up with water.2. Should be selective.3. Should have the big capacity in relation to extractive.4. The density of extragent should be difference from water density.5. Should have the minimum viscosity.6. Should be inexpensive.7. Cannot be explosive.
11Classification extraction processes: Periodical extraction - is the process in which separatory funnel (which contain substance which extragent) is shakedContinuous extractionCountercurrent extraction
12Schematic diagram of a Soxhlet extractor. 1: Stirrer bar/anti-bumping granules2: Still pot (extraction pot) - still pot should not be overfilled and the volume of solvent in the still pot should be 3 to 4 times the volume of the soxhlet chamber.3: Distillation path4: Soxhlet Thimble5: Extraction solid (residue solid)6: Syphon arm inlet7: Syphon arm outlet8: Expansion adapter9: Condenser10: Cooling water in11: Cooling water out
142. The main quantitative characteristics of extraction. Factor or extraction efficiencyR = ν (A) / ν (A)owhere ν (A) – moles of solute in organic phaseν (A)o – moles of solute initially present in water phaseExtraction efficiency for single extraction
15Extraction efficiency: for multiple (m) extractionSeparation coefficient (factor) of A, B ions equal relationship the distribution ratio this ions
17Mn++n(HL)O=(MLn)o+nH+ Extraction constant for process:Mn++n(HL)O=(MLn)o+nH+
18Extraction constant is function from: formation constant of complex, which is extracted ()Acid dissociation constant of extraction reagent if it forms extraction compound ()Distribution ratios of extraction reagent ()Distribution ratios of extraction complex ()рН of medium (optimum)
193. Types of extraction systems 1. Halogenides with covalent linkage: HgCl2, HgJ2, SbJ3, AsBr3, GeCl4, element iodine etc.2. Intracomplex salts: dithizonate, dithiocarbamates, oxyquinolines, oxyns, β-diketonate, and also di-(2-ethylhexyl)-phosphates actinoids, rare-earth and some other elements, etc.3. Complex metal acids: HFeCl4, HІnBr4, HSbCl6, etc.
204. coordinatively not solvated (a) and coordinatively solvated (b) salts: a) Salts tetraphenyl arsonium, tetraphenyl phosphonium etc.b) The compounds which is formed at extraction uranyl nitrate and nitrate of thorium by tributyl phosphate from nitrate solutions.5. heteropoly compounds of phosphorus, arsenic, silicon, vanadium, molybdenum, tungsten etc.!!!! Most widely is used in extraction process intracomplex salts, complex metalo halogenide acids and coordinatively solvated (b) salts
214. The main organic reagents which use in extraction method. 8-oxyquinoline reacts with more than 50 elementsAcetylacetonate forms compound with more than 60 elementsThionyl trifluoride acetone is used for excretion and separation actinoids.dithizon is used for determination of Pd, Au, Hg, Ag, Cu, Bi, Pt, In, Zn, Cd, Co, etc.!!! It is of great importance in the toxicological analysis.Sodium diethyl dithiocarbamate reacts with several tens of elements
22For increase of selectivity extraction: Create optimum рН mediumUse masking (reactions of complexation, oxidation-reduction, precipitation)
235. Usage of extraction in the drug analysis Extraction is used for:Separation of elementsConcentrating impuritiesClearings of the basic component from impurities in the process of synthesis of substances of drugsDefinition of the basic component from impurities in the process of synthesis of substances of drugs
24For identification and quantitative definition of chemical agent or substances-markers in the process of the analysis of phytogenesis drugsIncrease of sensitivity and selectivity of reactionsStudying of formation constant of complexsStudying of substance condition in a solution (a charge, polymerisation degree)Reception of extracts, tinctures, fermental preparations, antibiotics, preparations from a different biological material.
25Usage of extraction as method of concentrating and definition Absolute concentrating is reached at usage of smaller volume of an organic phase in relation to initial volume of a water solution.Relative concentrating is an increase in impurity concentration in relation to the main component.Especially important role extraction is by connection with physical and physical-chemical methods of the analysis - hybrid methods of the analysis which have such advantages:High sensitivitySelectivitySpecificityrapid analysis method
26Extraction of medicinal herbs includes stages: Drying (sometimes it is not necessary)Crumbling upSiftingSelection of optimum extragentChoice of an optimum technique extractionExtraction (moisten, passage extragent through pores, dissolution of substances in the middle of cell, diffusion of substance molecules through cellular covers, mass-carrying extraction substances from a surface of particles in extragent).
27Analytical techniques of reception of an extract for the purpose of medicinal herbs analysis on high quality:Extraction to a full attrition (percolation with 1 g medicinal herbs through burret)Single extraction of raw material shot (by boiling 1 g raw materials with extragent)Equilibrium extraction (for 4-5 hour balance between internal extrageny in medicinal herbs and the external extract, analyzes an extract part)!!! In the biochemical and toxicological analysis extraction is used for excretion of substances from animal and herb tissues, as fresh and dried up.