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NSS Chemistry Elective Analytical Chemistry Chan T.W. Dominic Department of Chemistry, The Chinese University of Hong Kong Importance of Analytical Chemistry in Hong Kong • Chemistry-related jobs in HK 1. Government Laboratory 2. Testing Laboratories – – – – – – Jockey Club Racing Laboratory Hospital Laboratory Enviropace Limited Productivity Council Pharmaceutical companies Private laboratories, such as BV, SGS,…etc. 3. Secondary School Teaching 4. Sales and Marketing 2 Importance of Analytical Chemistry in Hong Kong • Undergraduate Curriculum in Chemistry 1. 2. 3. 4. 5. Physical Chemistry Organic Chemistry Inorganic Chemistry Analytical Chemistry Computational Chemistry ¼ - ⅕ weightings • Postgraduate Programmes in Chemistry 1. MSc in Analytical Chemistry (HKBU) 2. MPhil / PhD in Analytical Chemistry Disciplines 3 Curriculum Comparison between NSS, CE and AL for Analytical Chemistry Detecting the presence of chemical species (Ch 61) 1. Detection of gases (Mostly covered in HKCEE, except the detection of HCl) 2. Detecting the presence of some metal ions by flame tests (Covered in HKCEE) 3. Qualitative analysis of ionic compounds – cations and anions (Mostly covered in HKCEE, except the detection of Mg2+) 4. Chemical tests for some functional groups of carbon compounds (Functional groups include C=C, −OH, −CHO, >C=O and −COOH) (HKAL: only addition-elimination (condensation) reactions with hydrazines) 5. Separation of a mixture of known substances (Covered in HKCEE) 4 Curriculum Comparison between NSS, CE and AL for Analytical Chemistry Separation and purification methods (Ch 62) 1. Separation and purification methods - Crystallization, distillation / fractional distillation, liquid-liquid extraction, column and thin layer chromatography (Mostly covered in HKAL, except column chromatography) - Determine the Rf values of substances in a chromatogram - Justify the choice of an appropriate method used for the separation of substances in a mixture 2. Tests for purity - Determine the melting point or boiling point of a substance - Examine the purity of a substance by measuring its melting or boiling point 5 Curriculum Comparison between NSS, CE and AL for Analytical Chemistry Quantitative methods of analysis (Ch 63) 1. Gravimetric analysis 2. Volumetric analysis - (HKCEE: Simple volumetric work involving acids and alkalis) - (HKAL: Acid-base titration and the choice of indicator plus general knowledge acquired from experiments under TAS scheme) 3. Process of a quantitative analysis 6 Curriculum Comparison between NSS, CE and AL for Analytical Chemistry Instrumental analytical methods (Ch 64) 1. Colorimetry - (HKAL: Treated briefly in “rate of chemical reaction”) - Construct a calibration curve and use it for the determination of the concentration of an unknown solution 2. Infrared (IR) spectroscopy - (HKAL: Structure determination of organic compounds) - Identify C-H, O-H, N-H, C=C, CΞC. C=O & CΞN from an IR spectrum using a correlation table 3. Mass spectrometry - (HKAL: A brief account of the mass spectrometer in determining relative isotopic, atomic and molecular masses) - Identify R+, RCO+ and C6H5CH2+ from a mass spectrum 7 Curriculum Comparison between NSS, CE and AL for Analytical Chemistry The role of analytical chemistry in our daily lives (Ch 66) 1. Analysis of food and drugs 2. Environmental protection 3. The chemistry aspects of forensic science 4. Clinical diagnoses (Not covered in HKCEE & HKAL) 8 Overview of Chemical Analysis Purpose of the analysis Real Samples: Mixture Analysis Separation & Purification Qualitative Target Specific Analysis Non-specific Analysis Quantification • • • Limit of detection Accuracy of the measurement Uncertainties 9 Qualitative Analysis • Chemical tests for gases, O2, H2, HCl, … • Flame test for metal ions • Chemical tests for functional groups of organic compounds • Identification of common cations and anions 10 Introduction of Separation Sciences - Importance of sample purity for chemical analysis - Conventional separation sciences Crystallization Distillation Liquid-liquid extraction - Advanced separation methods Concept (mobile/stationary phases) Illustration (paper chromatography) Chromatography Simple classification (thin-layer & column) Indexing method (Rf-value) 11 Spectroscopic Analysis Colorimetry - quantitative analysis Infrared Spectrometry – functional group analysis Mass Spectrometry - molecular mass measurement and structural analysis 12 Web Resources for IR and MS Information Spectral Database for Organic Compounds SDBS - by National Institute of Advanced Industrial Science and Technology, Japan http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng University of Wisconsin-Madison – Chemistry Library http://chemistry.library.wisc.edu/subject-guides/spectroscopy.html NIST Chemistry WebBook - by National Institute of Standards and Technology http://webbook.nist.gov/chemistry/ 13 The Role of Analytical Chemistry Forensic science Toys Analysis of food and drugs Doping control Textiles Analytical Chemistry Clinical diagnosis Environmental protection Gemstones and Antiques 14 Analysis of Food and Drugs - Residual pesticides in vegetables - Malachite green§1 in eel and other fish products - Harmful additives in food: e.g. Melamine in milk§2 products Hong Kong Standard, 23 Sept 2008 Related Organizations: - Government Laboratory – Forensic Sciences Division - Food and Environmental Authority §1 Rapid §2 Commun Mass Spectrom. 1998;12(21):1625-34 http://www.sielc.com/compound_404.html 15 Environmental Protection - Heavy metal analysis in drinking water - Air pollutants, e.g. formaldehyde, NOx, O3, SOx,.. etc - Dixoin (75 congeners) and polychlorinated biphenyls (209 congeners) analysis§ Related Organizations: - Government Laboratory – Environmental Monitoring Division - Environmental Protection Agency (EPA) - Enviropace Limited - Greenpeace - Water Department §More 16 information: http://www.pacelabs.com The Chemistry Aspects of Forensic Science - Development of latent fingerprints, e.g. Ninhydrin, cyanoacrylate fuming, laser luminescence - Body fluid analysis, e.g. DNA fingerprinting - Analysis of unknown powders/pills Andrzej Tokarski/Dreamstime.com Related Organization: - Government Laboratory – Forensic Sciences Division 17 Clinical Diagnosis - A biomarker is a substance that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. - e.g. Glucose level Creatinine Dopamine Diabetes Kidney malfunction Parkinson’s disease Genomics, Proteomics, Metabolomics Related Organizations: - Hospital Authority - Clinical testing laboratories 18 Thank you for your attention! Who should take Analytical Chemistry? Students with: • good mathematical ability: calculations and plot graphs • good analytical ability: interpreting different spectra (IR and MS), qualitative analysis 20