Organic Analysis Basic concepts

Elements and Atoms Fundamental building block of all substances is the element. Fundamental building block of all substances is the element. Atom smallest particle of an element that can exist but retain identity as that element. Atom smallest particle of an element that can exist but retain identity as that element.

The Periodic Table All elements are listed systematically. All elements are listed systematically. - elements are arranged according to similar properties. groups contain elements with similar properties in vertical columns. groups contain elements with similar properties in vertical columns. periods are horizontal rows of elements. periods are horizontal rows of elements.

Periodic table GROUPSGROUPS P E R I O D S

What are Compounds? A compound is combination of at least 2 elements. A compound is combination of at least 2 elements. Compounds have different physical and chemical properties than either element alone. Eg. Ag 2 S, CO 2 Compounds have different physical and chemical properties than either element alone. Eg. Ag 2 S, CO 2

Physical States of Matter Matter is classified into three physical states Matter is classified into three physical states SOLID LIQUID GAS (VAPOR) Substances can change from one state to another eg. sublimation, freezing, evaporation, condensation. Substances can change from one state to another eg. sublimation, freezing, evaporation, condensation.

Phases of matter Different phases are formed when two substances will not mix. Different phases are formed when two substances will not mix. Eg. oil and water.

Chemical Bonds Attractive forces that hold the atoms or molecules of a substance together. Solids have strong attractive forces but gases have weak bonds allowing the molecules to move in any and all directions.

Organic and Inorganic Analysis Organic substances always contain the element carbon. Everything else is inorganic! Properties of organic and inorganic materials are very distinct therefore they require different types of tests. Properties of organic and inorganic materials are very distinct therefore they require different types of tests.

Qualitative versus Quantitative testing. Qualitative (think “quality”) tests state the identity only eg. Heroin and quinine. Qualitative (think “quality”) tests state the identity only eg. Heroin and quinine. Quantitative (think “quantity”) also determines how much there is, either % or weight. Eg. Heroin sample- 90% heroin and 10% quinine. Quantitative (think “quantity”) also determines how much there is, either % or weight. Eg. Heroin sample- 90% heroin and 10% quinine.

Analysis of Organic Materials. Common analytical techniques: Common analytical techniques: 1. Spectrophotometry 2. Chromatography

Chromatography Useful for analyzing samples with many different components eg. Drug mixtures. Useful for analyzing samples with many different components eg. Drug mixtures. Theory: chemical substances tend to partially escape into the surrounding environment when dissolved in liquid OR absorbed on a solid surface. Theory: chemical substances tend to partially escape into the surrounding environment when dissolved in liquid OR absorbed on a solid surface.

Equilibrium : point where the number of molecules leaving the liquid phase = number of molecules entering the liquid phase i.e. no further change Equilibrium : point where the number of molecules leaving the liquid phase = number of molecules entering the liquid phase i.e. no further change Partitioning : movement/dissociation to liquid or gas phase is determined by the solubility of the gas in the liquid. Partitioning : movement/dissociation to liquid or gas phase is determined by the solubility of the gas in the liquid. Terminology

Moving and Stationary phases : Moving and Stationary phases : In chromatography one phase is always moving (“moving phase”) over another (“stationary phase”). SOLIDLIQUIDGAS Different types of chromatography vary in both their stationary and moving phases. Different types of chromatography vary in both their stationary and moving phases. Terminology

H.P.L.C. and G.C. H.P.L.C. H.P.L.C. High Performance Liquid Chromatography G.C. G.C. Gas Chromatography Gas Chromatography

Thin layer Chromatography (T.L.C.)

Main chromatographic processes ProcessAbbreviation Moving Phase Stationary Phase High Performance Liquid Chromatography H.P.L.C.liquid Column filled with fine particles Gas Chromatography G.C. Inert “carrier gas”, usually nitrogen or helium Thin film of liquid contained in a column. Thin layer chromatography T.L.C. Liquid, usually a solvent Solid (plate coated with silica gel or aluminium oxide

Gas Chromatograph.

Gas Chromatography (G.C.) The component with the greatest affinity for the moving phase (i.e. gas) will travel through the column faster  separation of the mixture’s components.

Chromatograms The detector records the separation of the different components of the mixture as a function of time. The detector records the separation of the different components of the mixture as a function of time. Each peak is one component of the mixture. Each peak is one component of the mixture. Time required for the peak to emerge is called the retention time Time required for the peak to emerge is called the retention time

Pyrolysis Gas Chromatography High temps ( o C) will decompose solid materials to gaseous products that can be analyzed by the G.C. High temps ( o C) will decompose solid materials to gaseous products that can be analyzed by the G.C. Chart of different components of the mixture is called a pyrogram. Chart of different components of the mixture is called a pyrogram.

Pyrograms

High Performance Chromatography (H.P.L.C.) takes place at room temperature. takes place at room temperature. Sample components are retarded to different degrees depending on their interaction with the stationary phase. Sample components are retarded to different degrees depending on their interaction with the stationary phase. Useful for analysis of organic explosives and heat sensitive drugs. Useful for analysis of organic explosives and heat sensitive drugs.

Thin Layer Chromatography Solid samples are dissolved in a solvent prior to analysis, then “spotted” onto the solid support. Solid samples are dissolved in a solvent prior to analysis, then “spotted” onto the solid support. Components with the greatest affinity for the moving phase (liquid solvent) will move farthest. Components with the greatest affinity for the moving phase (liquid solvent) will move farthest. Visualize spots with fluorescent dye or other chemicals. Visualize spots with fluorescent dye or other chemicals.

Calculation of R f value Identification involves running a known/authentic sample on the same T.L.C. plate. R f = distance traveled by the component distance traveled by the moving phase

Thin Layer Chromatography Advantages: Advantages: 1. Used for mixtures eg. drugs which are not pure. 2. Small amount of sample….approx. 100ug. 3. Can run multiple samples simultaneously.

Gel Electrophoresis Separates mixtures according to their size and charge as determined by migration within an agarose gel which has an electrical current running through it. Separates mixtures according to their size and charge as determined by migration within an agarose gel which has an electrical current running through it. Used to separate complex biochemical mixtures eg. proteins and DNA. Used to separate complex biochemical mixtures eg. proteins and DNA. Separate components appear as “bands” on the gel. Separate components appear as “bands” on the gel.