Dnyanasadhana College, Thane Department of Chemistry S.Y.B.Sc. Welcome Dr.G.R.Bhagure

1. Dnyanasadhana College, Thane • Department of Chemistry S.Y.B.Sc. Welcome • Dr.G.R.Bhagure

2. SYBSC ANALYTICAL CHEMISTRYSem.III INTRODUCTION TO ANALYTICAL CHEMISTRY By Dr.Bhagure G.R.

3. Defination of Analytical Chemistry • Analytical Chemistry is branch of chemistry which deals with the study of theory and practice of methods used to determine composition of matter.

13. CLASSICALMETHODS

14. MODERN METHODS

15. MODERN METHODS

16. Steps Involved in the Analysis Of Sample

17. Aim/Purpose of analysis: • The purpose for which analysis is required must be mention specifically. • Ex.i) In forensic science Laboratory analysis of blood sample and food sample is carried out which may be used as evidence in the court of law. • To maintain the quality control of the product.

18. 2) Sampling: • The various steps/ techniques used to get sample is called as sampling. • Sample: A part of bulk material which represents all essential characteristic to that of bulk is called as sample. • Sampling techniques are not same for solids, liquids or gases. • Each type of material has its own sampling techniques/method to obtain sample.

19. Selection of Analytical method: • The success or failure of an analysis is often critically dependent upon the proper selection of method. • While selecting an analytical method following factors have to be considered. • Concentration of the component. • The complexity of the materials/presence of interfering material • The probable concentration of the species of interest • Degree of Accuracy

20. Sensitivity and detection limit • Selectivity • Duration of an analysis • Speed ,time and Cost of analysis • Availability of equipments • Skill person for handling the instrument. • All the above factors should be taken into account combinedly, to select the proper method.

21. Dissolution of the sample/ processing a sample : • Sample obtained cannot taken directly for the analysis because sample may not be in proper physical form and no suitable sample size. • Most analyses are performed on solutions of the sample. • Inorganic sample are dissolve by (1) treatment with hydrochloric acid, nitric acid, mixture of hydrochloric and nitric acids, sulphuric acid or perchloric acid, and • (2) fusion with an acidic or basic flux followed by treatment with water or an acid.

22. (2) fusion with an acidic or basic flux followed by treatment with water or an acid. • Organic solvents are preferentially used to dissolve the samples of organic nature. • After dissolution sample solution is diluted to known volume.

23. v) Separation of Interfering Substances • The interfering substances are the compounds or elements that prevent the direct measurement of the species being determined. • There are two ways to achieve separation (i) by isolating the desired Constituent in a measurable form by precipitation, filteration or by Masking of substance. • Ex.Cycnide ion can be used to mask Cd, Zn when determination of lead is carried out. • (ii) By removing the interfering substances from the desired constituent by filtration/distillation

24. Actual Measurement /analysis: • Instrument or Volumetric glass ware should be standardized or calibrated before measurement. • Replicate measurement with different aliquot of same sample is carried out to avoid error. • Ex. In volumetric determination at least three B. R. are taken to avoid error.

25. Processing data: • Replicate measurements/ readings are subjected for statistical treatment. • Mean, mode, median, range, standard deviation is calculated to know the central tendency and dispersion of the measurement.

26. Interpretation of the Measurement: • The result obtain after analysis and processing is express in common terms such as Normality, Molarity, PPM, percentage etc. Obtain value/result is then correlated with other factors to understand and to achieve proper conclusion.

27. Performance characteristics of analytical Method • Precision: • It is the agreement between Indiudual observations of same set. • Accuracy: • It is defined as closeness of the observed value with the true value. • Limit of detection(LOD): • Minimum amount of concentration of a component that can be detected with a given degree of confidence. • Limit of Quantification (LOQ): • Minimum amount of concentration of a component that can be estimated with a given degree of confidence is termed as LOQ.

28. Limit of Linearity (LOL) : • It is defined as maximum concentration range up to which instrument is produces linear response. • Sensitivity: It is a measure of ability of method to discriminate between two small concentration differences in the analyte • Sensitivity is measured in terms of slope of the calibration curve. If the slope is greater sensitivity of the method is high and vise-versa.

29. Selectivity: It is defined as degree to which the method is free from interferences from other components present in the matrix. • Dynamic range: • It is the concentration range from limit of Quantification (LOQ) to Limit of Linearity (LOL).

30. Quantitive Analysis: • Calibration Curve method: • A calibration curve is used to determine the unknown concentration of an element in a solution. The instrument is calibrated using several solutions of known concentrations. The property to be measured of each known solution is measured and then a calibration curve of property measured v/s concentration is plotted. • The property of a sample solution is measured .The unknown concentration of the element is then calculated from the calibration curve

31. Calibration Curve method: Property is directly proportional to concentration Property

32. Method of Standard Addition: • In this method the property of unknown (X) is first find out against blank. Then a series of standards having definite amount of unknown (X) plus varying amount of standard are prepared and diluted to same volume in each case .Their property is then measured. A graph of measured property against concentrations of standard (S) gives a linear curve. The concentration of the unknown can be determined by extrapolation of line which cuts to X axis.

33. Standard addition method Property .. .. . Absorbance--- X X+S X+2S X+3S X+4S Concentration----- Concentration of Unknown.

34. Internal Standard Method: • A series of standard solution containing the same elements as that present in sample solution is prepared. A fixed quantity of suitable internal standard is then added to each of standard solutions, blank and sample solutions alike. The measurable property of each of above standard solutions and sample solutions are measured. The measurable property for each of above standard solution (Is) & (Ii) and sample solution (Ix&Ii) are measured at different wavelength one corresponds to element and other corresponds to the internal standard. These measurements are made against blank .The ratio of measured property of the standard solutions to that of internal standard (Is/Ii) are plotted against the concentration of standard solutions. This gives a straight line from this curve concentration of sample solution can be read by finding where the ratio (Ix/Ii) falls on concentration scale.

35. Internal Standard addition method Ax ----- At Concentration-----

36. Application of Analytical Methods: • Analytical chemistry is applicable to each and every branch/field. If one tries to prepare the list of application the list will be unending. All industries irrespective of what they produce, all of these depend upon the applications of analytical methods. The application of analytical chemistry is as follows;

37. Research and Development : • In every industry research is carried out to develop new product which are having application. In this area the analytical characterization and its quantification is carried out by various analytical methods. Ex.IR spectroscopy, UV spectroscopy, Mass spectroscopy .Gas chromatography etc. • Quality control unit : • In every industry there is Quality control unit where the quality of raw material as well as finished product is monitored/ checked by analytical methods. • Ex. Gas chromatography, HPLC, Flame emission spectroscopy, AS can be used in • Qualitative and quantitative analysis.

38. UV Spectrometer

39. Mass Spectrometer

40. HPLC Instruments

41. Organic Industry : • The industry which manufacture the organic bulk chemicals can be called as Organic Industry. To determine the composition, purity and quality of both raw material as well as finished product. Analytical methods are also required to improve the process used, percentage yield and waste products are used. • Quantitative information on the purity level and impurity level are obtained by advanced instruments like Gas chromatography, HPLC, Flame emission spectroscopy, Atomic Absorption Spectroscopy.

44. Pharmaceutical industry: • In research and development wing of the company analytical chemistry plays very versatile role. As per patent law no pharmaceutical company can duplicate the product of another company. So every company has to continue the R.D. to develop new product. Analytical techniques like Gas chromatography, HPLC,Mass spectroscopy, GCMS, thin layer chromatography is useful to find out progress of the reaction and quantification of the product .Thermal methods are used to find out thermal stability of the product. • All the mentioned techniques are also used to maintain the quality and quantity of various ingredients present in medicines.

50. Metallurgical Industry : • The property of any alloy depends upon the adequate proportion of element present in it. • Ex.In steel alloy properties of steel depends on carbon content and proportion of other element such as Cr,Mn,Ni etc. • Analytical methods such as Atomic absorption spectroscopy, vacuum emission spectroscopy are used to find out the various elements present in steel alloy, brass alloy, bronze etc.