lecture 1 ; Introduction to Analytical Chemistry, by Dr. Salma Amir

1. Lecture No. 01 Course title: Fundamental Analytical Chemistry Topic: Introduction to Analytical chemistry Course instructor: Dr. Salma Amir GFCW Peshawar

2.  Analytical chemistry is the branch of chemistry that deals with the analysis of different substances.  It involves the separation, identification, and the quantification of matter. It involves the use of classical methods along with modern methods involving the use of scientific instruments. Analytical chemistry involves the following methods:  The process of separation isolates the required chemical species which is to be analysed from a mixture.  The identification of the analyte substance is achieved via the method of qualitative analysis.  The concentration of the analyte (quantification) in a given mixture can be determined with the method of quantitative analysis.

3.  Analytical chemistry is concerned with the chemical characterization of matter and answering for two basic questions about a material sample: 1. What is present in the sample (qualitative) 2. How much is present in the sample (quantitative)

4. Historical Background  Analytical chemistry has been important since the early days of chemistry, providing methods for determining which elements and chemicals are present in the object in question. During this period significant contributions to analytical chemistry include the development of systematic elemental analysis by Justus von Liebig and systematized organic analysis based on the specific reactions of functional groups.  The first instrumental analysis was flame emissive spectrometry developed by Robert Bunsen and Gustav Kirchhoff who discovered rubidium (Rb) and caesium (Cs) in 1860.  Most of the major developments in analytical chemistry take place after 1900. During this period instrumental analysis becomes progressively dominant in the field. In particular many of the basic spectroscopic and spectrometric techniques were discovered in the early 20th century and refined in the late 20th century

5.  The separation sciences follow a similar time line of development and also become increasingly transformed into high performance instruments. In the 1970s many of these techniques began to be used together as hybrid techniques to achieve a complete characterization of samples.  Starting in approximately the 1970s into the present day analytical chemistry has progressively become more inclusive of biological questions (bioanalytical chemistry), whereas it had previously been largely focused on inorganic or small organic molecules. Lasers have been increasingly used in chemistry as probes and even to initiate and influence a wide variety of reactions. The late 20th century also saw an expansion of the application of analytical chemistry from somewhat academic chemical questions to forensic, environmental, industrial and medical questions, such as in histology

6. Types of Analysis The discipline of analytical chemistry consists of qualitative analysis and quantitative analysis and each one of these two types can be either classical or instrumental . 1. Qualitative analysis: Qualitative analysis deals with the identification of elements, ions, or compounds present in a sample (we may be interested in whether only a given substance is present) 2. Quantitative analysis: Quantitative analysis deals with the determination of how much of one or more constituents is present. The sample may be solid, liquid, gas, or a mixture.The presence of gunpowder residue on a hand generally requires only qualitative knowledge, not of how much is there, but the price of coal will be determined by the percent of undesired sulfur impurity present.

7. Qualitative analysis: Qualitative analysis deals with the identification of elements, ions, or compounds present in a sample (we may be interested in whether only a given substance is present)  Classical analysis In this type, the substances can be detected either by a chemical reaction OR physical change. For example, when silver nitrate solution is added to the sample solution a white precipitate formation indicates the presence of chloride ion in the sample. There are also many reagents that give distinctive colors with some of the substances and can be used in the detection of these substances . The flame also can be used for the detection of some common metals  Instrumental analysis Currently there are many instruments that are separate and distinguish substances ( organic or inorganic ) in the sample, such as gas chromatography – mass spectrometry ( GC – MS ) , High performance liquid chromatograophy - mass spectrometry ( HPLC – MS ) , infrared spectra ( IR ) and induced coupled plasma – mass spectrometry ( ICP – MS ) or ICP – AES ( Atomic Emission Spectrometry )

8. 2. Quantitative Analysis Quantitative analysis deals with the determination of how much of one or more constituents is present. and uses two types of analysis depending on the concentration of the substance in the sample, namely classical chemical analysis and instrumental analysis.  Classical chemical analysis: Which depends on the chemical reaction, such as volumetric analysis and gravimetric analysis And it uses simple equipment such as burettes , balances , flame , furnace . And is used to estimate high concentrations ( more than 0.001 M)  Instrumental Analysis : This type of analysis uses instruments and depends on the physical and physico-chemical properties of the substance being analyzed ( analyte ) such as absorption or emission of electromagnetic radiation (spectroscopic methods of analysis ) or electrical properties of the substance being analyzed such as voltage or current intensity or electrical conductivity ...... etc. (electrochemical methods of analysis) and finally the methods of separation such as chromatography All these methods are used to estimate low concentrations of the analyte (less than 0.001 M ) , but most of the instrumental analysis methods require expensive instruments 

9. Aim/Purpose of Analytical chemistry  Analytical chemistry is a scientific discipline used to study the chemical composition, structure and behavior of matter.  The purpose of chemical analysis is to gather and interpret chemical information that will be of value to society in a wide range of contexts.  The gathering and interpretation of qualitative, quantitative and structural information is essential to many aspects of human endeavor, both terrestrial and extra-terrestrial. The maintenance of, and improvement in, the quality of life throughout the world, and the management of resources rely heavily on the information provided by chemical analysis. Manufacturing industries use analytical data to monitor the quality of raw materials, intermediates and products.

10. Scope/Applications of Analytical Chemistry Analytical data are required in a wide range of disciplines and situations that include not just chemistry and most other sciences, from biology to zoology, but the arts, such as painting and sculpture, and archaeology. Space exploration and clinical diagnosis are two quite disparate areas in which analytical data is vital. Important areas of application include the following.  In medicine, analytical chemistry is the basis for clinical laboratory tests which help physicians diagnosis disease and chart progress in recovery.  In quality control, In many manufacturing industries, the chemical composition of raw materials, intermediates and finished products needs to be monitored to ensure satisfactory quality and consistency. Analytical chemistry provides the means of testing raw materials and for assuring the quality of finished products whose chemical composition is critical. Many household products, fuels, paints, pharmaceuticals, etc. are analysed by the procedures developed by analytical chemists before being sold to the consumer.

11.  Monitoring and control of pollutants. The presence of toxic heavy metals (e.g., lead, cadmium and mercury), organic chemicals (e.g., polychlorinated biphenyls and detergents) and vehicle exhaust gases (oxides of carbon, nitrogen and sulfur, and hydrocarbons) in the environment are health hazards that need to be monitored by sensitive and accurate methods of analysis, and remedial action taken. These are often evaluated by testing for suspected contaminants using the techniques of analytical chemistry.  The nutritional value of food is determined by chemical analysis for major components such as protein and carbohydrates and trace components such as vitamins and minerals. Indeed, even the calories in a food are often calculated from the chemical analysis.  Forensic analysis Analysis related to criminology; DNA finger printing, finger print detection; blood analysis. · Bioanalytical chemistry and analysis - detection and/or analysis of biological components (i.e., proteins, DNA, RNA, carbohydrates, metabolites, etc.).

12.  Geological assays. The commercial value of ores and minerals is determined by the levels of particular metals, which must be accurately established. Highly accurate and reliable analytical procedures must be used for this purpose, and referee laboratories are sometimes employed where disputes arise.  Fundamental and applied research. The chemical composition and structure of materials used in or developed during research programs in numerous disciplines can be of significance. Where new drugs or materials with potential commercial value are synthesized, a complete chemical characterization may be required involving considerable analytical work. Combinatorial chemistry is an approach used in pharmaceutical research that generates very large numbers of new compounds requiring confirmation of identity and structure.  Clinical and biological studies. The levels of important nutrients, including trace metals (e.g., sodium, potassium, calcium and zinc), naturally produced chemicals, such as cholesterol, sugars and urea, and administered drugs in the body fluids of patients undergoing hospital treatment require monitoring.