Chapter 1 introduction to analytical chemistry

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1. Lecturer: Dr Sumaiya Zainal Abidin Room: A3-08 Email: 2. 4.00 PM 5.00 PM (Tuesday) 10.00 AM 11.00 AM (Wednesday) 3. Lectures 4.00 PM 6.00 PM (Thursday; W-DK-01; 2hours) 4.00 PM 5.00 PM (Friday; W-DK-01;1 hour) 4. Method of Assessment % DistributionTest 120%Test 220% Presentation 6% Quizzes7% Assignments7% Final Examination40% Total 100% 5. David Harvey Modern Analytical Chemistry(McGraw Hill) Kealy & Haines Analytical Chemistry Skoog et al. Fundamental of AnalyticalChemistry 6. CLASS POLICY 100% attendance PunctualityAsk questions 7. Chemical analysis includes any aspect of thechemical characterization of a samplematerial. Analytical Chemistry? Science of Chemical Measurements 8. Quantitation: How much of substance X is in the sample? Detection: Does the sample contain substance X? Identification: What is the identity of the substance in the sample? Separation: How can the species of interest be separated fromthe sample matrix for better quantitation andidentification? 9. Analytical Chemistry provides the methods andtools needed for insight into our material worldfor answering four basic questions about amaterial sample? What? Where? How much? What arrangement, structure or form?(Fresenius J. Anal. Chem. 343 (1992):812-813) 10. Analytical chemists work to improve the reliability of existingtechniques to meet the demands of for better chemicalmeasurements which arise constantly in our society. They adapt proven methodologies to new kinds of materials or toanswer new questions about their composition. They carry out research to discover completely new principles ofmeasurements and are at the forefront of the utilization of majordiscoveries such as lasers and microchip devices for practicalpurposes. 11. Classical methods: early years (separation of analytes) viaprecipitation, extraction or distillation Qualitative: recognized by color, boiling point, solubility,taste Quantitative: gravimetric or titrimetric measurements Instrumental Methods : newer, faster, more efficient Physical properties of analytes: conductivity, electrodepotential, light emission absorption, mass to charge ratio andfluorescence, many more 12. Qualitative analysis is what.Qualitative analysis is what.Quantitative analysis is how much.Quantitative analysis is how much. Gary Christian, Analytical Chemistry, 6th Ed. (Wiley) 13. Gravimetric Methods determine the mass of the analyte or somecompound chemically related to it.Volumetric Methods measure the volume of a solution containingsufficient reagent to react completely with the analyte Electroanalytical Methods involve the measurement of electricalproperties such as voltage, current, resistance, and quantity ofelectrical charge Spectroscopic Methods are based on the measurement of theinteraction between electromagnetic radiation and analyte atoms ormolecules, or the production of such radiation by analytes Miscellaneous Methods include the measurement of suchquantities as mass-to-charge ratio, rate of radioactive decay, heat ofreaction, rate of reaction, sample thermal conductivity, optical activity,and refractive index 14. An analysis involves several An analysis involves severalsteps and operations which steps and operations whichdepend on: depend on:the particular problem the particular problem your expertiseyour expertise the apparatus orthe apparatus orequipment available.The analyst should be The analyst should beinvolved in every step. involved in every step. Gary Christian, Analytical Chemistry, 6th Ed. (Wiley)Fig. 1.1. Steps in an analysis 15. Different methods provide aarange of precision, sensitivity, selectivity,Different methods provide range of precision, sensitivity, selectivity, and speed capabilities.and speed capabilities.Gary Christian, Analytical Chemistry, 6th Ed. (Wiley) 16. Numbers used in analytical chemistry: Units of measure Significant figuresMeasurable units used in analytical chemistry: Mass Volume solute) (of Concentration (of solvent) (of solution) 17. Units for Expressing Concentration Concentration is a general measurementunit starting the amount of solute presentin a known amount of solution/solventConcentration= amount of soluteamount of solution= amount of solute amount of solvent 18. Other Concentration Units Molarity, M Is the concentration of a particular chemical species insolution Formality is a substances total concentration in solution withoutregard to its specific chemical form Normality, N the amount of one chemical species reactingstoichiometrically with another chemical species EW = FW / n , n = number of equivalents N=nxM Molality used in thermodynamic calculation where a temperatureindependent unit of concentration is needed Weight, volume and weight to volume ratios - %w/w, %v/v and %w/vexpress concentration as units of solute per 100units of sample Parts per million, billion and trillion are the minute concentration unitswhich also use the compatible metric units as follows: ppm = mg/liter = g/mL ppb = g/liter = ng/mL ppt = ng/liter = pg/mL 19. Other Concentration UnitsNameUnits SymbolMolarityMoles solute/liters solutionMFormality No.FWs solute/liters solution FNormality No.EWs solute/liters solution NMolalityMoles solute/kg solvent mWeight %g solute/100g solution%w/wVolume %mL solute/100mL solution%v/vw/v % g solute/100 mL solution%w/vppm g solute/106 solution ppmppb g solute/109 g solution ppbppt g solute/1012 g solutionppt 20. List of Presentation Topics Gravimetric Analysis Titrimetric Analysis UV-Vis Infra-Red Atomic Absorption Spectrometry Flame atomic Emission Spectroscopy Inductively Coupled Plasma Spectrometry Gas ChromatographyGas Chromatography Mass Spectrometry Liquid Chromatography Liquid Chromatography Mass Spectrometry 21. Basic/General Principles and Theory Types/Variation Description of instruments (if any) Mechanism of Analysis/Method/Instruments Examples and Applications