Presentation on theme: "Chapter 5: Organic Analysis A common dose estimate for acute toxicity is the LD50 (Lethal Dose 50%). This is a statistically derived dose at which 50%"— Presentation transcript:
Chapter 5: Organic Analysis A common dose estimate for acute toxicity is the LD50 (Lethal Dose 50%). This is a statistically derived dose at which 50% of the individuals will be expected to die.
Acute toxicity (LD50 mg/kg) of acetaminophen Species Oral Rat Mouse338 Hamster Rabbit Dog mg/Kg
Acetaminophen metabolites found in urine
Figure 2.19 A molecular mimic
Objective: You will be able to explain the basic properties and functions of carbohydrates
Organic vs. Inorganic CarbohydratesCarbohydrates LipidsLipids ProteinsProteins Nucleic AcidsNucleic Acids Water Water Carbon dioxide Carbon dioxide Oxygen Oxygen Methane Methane
Carbohydrates Readily available source of energy Readily available source of energy Serve as raw material for synthesis of other molecules Serve as raw material for synthesis of other molecules Used as a structural component Used as a structural component Three major types is called: monosaccharide, Three major types is called: monosaccharide, disaccharides disaccharides polysaccharides polysaccharides
What do all Monosaccharide's have in common?
Paired Activity Create a unique monosaccharide based on the criteria discussed.Create a unique monosaccharide based on the criteria discussed. After you have built your molecule, write down what YOU think makes it unique.After you have built your molecule, write down what YOU think makes it unique.
Figure 5.4 Linear and ring forms of glucose
Figure 5.7b,c Starch and cellulose structures Figure 5.7b,c Starch and cellulose structures
(a) O CH 2 O H OH H H H NH C CH 3 O H H OH Figure 5.10 A–C The structure of the chitin monomer.
What popular drug is created from carbohydrates?
Objective: You will be able to state the properties of lipids and proteins
Lipids Fats, oils and waxes Fats, oils and waxes All are hydrophobic All are hydrophobic Three types: Three types: Triacylglycerols Triacylglycerols Phospholipids Phospholipids Steroids Steroids
FATS Triacylglycerol or fat is made up of 3 fatty acids and one glycerol Triacylglycerol or fat is made up of 3 fatty acids and one glycerol Are significant to forensics because many substances are stored in fats Are significant to forensics because many substances are stored in fats PCBs PCBs Marijuana, Cocaine, etc… Marijuana, Cocaine, etc… Because they are stored, there affect may be long lasting Because they are stored, there affect may be long lasting
Proteins Made up of a specific sequence of amino acids –Each protein has its own specific number of amino acids and in its own unique order This sequence will lead to a specific shape that will give the protein its function –Ex. Enzymes, hormones
Proteins Proteins have many functions in the body A key function is that they act as chemical messengers –Many of the illegal drugs cause their affect because they act as messengers
EXTRACELLULAR FLUID Receptor Signal molecule Relay molecules in a signal transduction pathway Plasma membrane CYTOPLASM Activation of cellular response Figure 11.5 Overview of cell signaling Reception 1 Transduction 2 Response 3
Drugs that act as messengers Opiates –Morphine –Heroin These chemicals help reduce pain
Opiate Receptors Three neurons engage in opiate action. When opiates bind to opiate receptors, a signal goes to the dopamine terminal (shown here as part of another neuron) to release dopamine. Dopamine binds to dopamine receptors, stimulating the post-synaptic cell and a positive emotional feeling
Nucleic Acids DNA Stores genetic information Stores genetic information Double stranded Double stranded Is transcribed to synthesize proteins Is transcribed to synthesize proteins__________________________________________RNA Translates DNA and carries out protein synthesis Translates DNA and carries out protein synthesis Single stranded Single stranded
Objective: You will be able to describe the theory of chromatography.
Analyzing Organic Compounds Quality versus quantity –Quality identifies exactly what it is –Quantity may be important because larger amounts of illegal substances may carry longer jail time Many times substances are in fact mixtures –Drug dealers may cut the drugs –This requires a different technique to identify the substance
Chromatography This technique has the ability to purify substances –It rips each component from mixture and separates it single components Theory of chromatography –Chemical substances partially escape into surroundings when: Dissolved in a liquid Absorbed into a solid
Dissolved in liquid Dissolved on a solid Gas chromatography TLC
Thin Layer Chromatography (TLC) Separation of mixture is done by using a stationary solid phase (paper) and moving liquid phase Still based on solubility of each substance in the liquid Substances that are highly soluble move faster
Analyzing the TLC sample A measurement of how far each component of a substance would then be taken –This will determine the R F value of a substance –A substances RF value can be used to HELP determine what it is –Not unique and other substances may have same R F value A direct comparison can also be made by running a known sample versus and unknown
Activity: We need to find out who wrote that note!!! Work with your group to develop a method to determine whose pen was used.Work with your group to develop a method to determine whose pen was used. You need to:You need to: –Give the names of the suspects –State which method you are going to use –Describe the science behind the method –Provide an outline of steps you are going to use
Gas Chromatography Can separate substances because of differences in solubility in a liquid –Force air to continuously move in one direction –Gas phase is moving phase, liquid phase is stationary phase The chemical race –High solubility means it wants to stay in liquid –This makes the highly soluble substance move slower
Objective: You will be able to explain how GC can be used for the quantitative and qualitative analysis of compounds. Do Now: Read Gas Chromatography on p. 123 and only first paragraph on 124Read Gas Chromatography on p. 123 and only first paragraph on 124 Differentiate between the two types of columns used in GCDifferentiate between the two types of columns used in GC
Activity Work in pairs to create a parts list for the gas chromatography machineWork in pairs to create a parts list for the gas chromatography machine Make sure you draw each part and give its functionMake sure you draw each part and give its function Use the diagram on p. 136 to help youUse the diagram on p. 136 to help you
Gas Chromatography Uses a stationary liquid phase and a moving gas phase Can separate substances because of differences in solubility in a liquid –High solubility means it wants to stay in liquid The chemical race –Force air to continuously move in one direction –Gas phase is moving phase, liquid phase is stationary phase Need large enough area so that the molecules can be fully separated
The GC Machine Sample is placed into the injector and travels through the column Carrier gas is typically nitrogen or helium Column is heated to keep substance being tested in a gaseous state As each substance in the sample emerges from the column, it enters a detector Here it is ionized by a flame that creates an electric signal This signal creates a chart called a chromatogram
Components of a Gas Chromatograph Inert gas Sample injected here This is heated to keep sample in gas state Creates a chromatogram
Chromatograms Chromatograms are plotted based on retention time Usually has a series of peaks which represents each substance from a mixture Qualitative analysis done by comparing retention time with known samples –Not 100% reliable because two substances may have same retention time Quantitative analysis is done by viewing how high the peak is
Each peak represents a different substance from the mixture Which substance had the highest solubility? A B C D E
Mixture of material in marijuana
chromatograms may also be able to identify substances by comparing to known standards.
Material must be a gas to enter GC Some material like paint, fibers and plastics cannot be readily dissolved into a liquid to go into the GC machine A technique called pyrolysis heats these materials so they decompose into gaseous materials –These materials are then injected into the GC machine
Objective: You will be able to explain how the mass spectrometer can be used to specifically identify a substance. Do Now: Read the chapter summary on p Read the chapter summary on p Give three things that you learned the best in this chapterGive three things that you learned the best in this chapter
Mass Spectrometer As the gas leaves the GC, it enters the MSAs the gas leaves the GC, it enters the MS Within the MS, a beam of electrons is shot at the substance breaking it down into fragmentsWithin the MS, a beam of electrons is shot at the substance breaking it down into fragments These fragments pass through an electric field which separates them by their massesThese fragments pass through an electric field which separates them by their masses The fragment masses are then recorded on a graphThe fragment masses are then recorded on a graph Each substance breaks down into its own characteristic patternEach substance breaks down into its own characteristic pattern
MS of Caffeine
Objective: You will be able to discuss the various properties of light Do Now: Read Electrophoresis on p Read Electrophoresis on p How are the processes of electrophoresis and TLC similar? Different?How are the processes of electrophoresis and TLC similar? Different? What is electrophoresis used for?What is electrophoresis used for?
Pair Work Read page (The Spectrophotometer) Explain how a spectrophotometer works by giving the function of the: Radiation source Monochromator Sample cell Detector and Recorder Explain how samples are prepared
Objective: You will be able to explain how the ultraviolet, visible and infrared spectrophotometer can be used in qualitative analysis. Do Now: Read Absorption of electromagnetic radiation on p Read Absorption of electromagnetic radiation on p How does spectrophotometry work?How does spectrophotometry work? Relate energy requirement to absorptionRelate energy requirement to absorption