INSTRUMENTAL ANALYSIS

1. TOPIC INSTRUMENTAL ANALYSIS PRESENTER SYED MUHAMMAD ALI APPRENTICE CHEMIST

2. INTRODUCTION The purpose of LABORATORY is to assist in QUALITY CONTROL of theRaw Material, intermediates and productsin a manufacturing unit:

3. Following samples are tested in FFBL Laboratory: • Raw materials (Natural Gas, Phos Acid, Liquid Ammonia, Water etc.) • Different Samples from Ammonia, DAP, Urea and Utilities plants at different stages of processing. • Packaging materials. • Environmental Control Analysis. • Special samples like metals & Alloys, scales & Deposits, Lube Oils, Plant Chemicals e.g. Potassium Carbonate, Tri Sodium Phosphate, Hydrazine, H2SO4, NaOH Solution etc.) • Above samples may be in solid, liquid, or gaseous form. • Different analytical methods are used for these analysis.

4. Methods of analysis • Quantitative methods of chemical analysis can be categorized into following types: • Classical (or wet) methods include: • Titrimetric, Gravimetric and Volumetric analysis • Instrumental methods • Chromatography, spectroscopy ,electrochemistry, Karl fisher • titration, potentiometry, ion selective analysis.

5. Advantages of instrumental analysis over classical methods • Accuracy: Because of repeatable results and fine calibration we can achieve more accurate results. For example: Automatic pH titrator is more accurate than manual indicator titration. • Precision: Results obtained from instruments are more precise than manual system. With the help of instruments we can achieve analysis results upto PPB level. • Time saving: Automatic analyzers can perform hundreds of samples by using automated samplers. Thus saving many man-hours.

6. DIFFERENT TYPES OF INSTRUMENTS BEING USED IN OUR LABORATORY: • GAS CHROMATOGRAPH • ATOMIC ABSORPTION SPECTROPHOTOMETER • UV-VISIBLE SPECTROPHOTOMETER • KARL FISHER TITRATOR • AUTOMATED KJELDHAL DIGESTOR AND DISTILLATOR • CONDUCTIVITY METER • pH METER

7. Gas Chromatograph (GC) This instrument is used to analyze various gas samples from Ammonia, Urea and Utilities plants.

8. Principles of Gas Chromatography: This method is based on adsorption of gaseous substances on solid surfaces in presence of gaseous mobile phase. This results in separation of the mixture of gases into individual components. Degree of separation depends on molecular weight, boiling point and affinity of adhesion with the solid phase. Permanent gases (N2, Ar, CO & CO2) and components of Natural gas (Hydrocarbons) are separated and analyzed.

9. H RESET Air Hydrogen Gas Carrier Gas Chromatograph • Gas inlet system • Column • Detector • Data system

10. Schematic Diagram of Gas Chromatograph

11. Commonly Used Detectors for GC: • Thermal conductivity (TCD): • Change in resistance of heated wire based on variation in thermal conductivity of the gases evolving from the column (wheat stone bridge principle) • Flame ionization (FID): • Destruction of combustible sample results in production of ions in flame • produces measurable current.

12. AA Spectrophotometer Atomic Absorption spectrophotometer is being used in our laboratory for various metal & non-metal analysis.

13. BASIC PRINCIPLES: ATOMIC ABSORPTION SPECTROSCOPY (AAS) is an analytical technique that uses absorption of light by the atoms of elements in order to measure their concentration. ATOMIC EMISSION SPECTROSCOPY is also an analytical technique that usesemission of light from excited atoms to determine analyte concentration

14. Schematic Diagram of an Atomic Absorption Spectrometer Light source atomizer monochromator Detector and hollow cathode Lamp readout device

15. Atomic absorption spectrometers have 4 major components 1 - A light source ( usually a hollow cathode lamp ) 2 - An atomizer 3 - A monochromator 4 - A detector , and read out device. 1- Light Source: The light source is usually a hollow cathode lamp of the element that is being measured. It contains a tungsten anode and a hollow cylindrical cathode made of the element to be determined.

16. Quartz window Pyrex body Cathode Anode Cathode Anode Hollow Cathode Lamp

17. 2 – Atomizer: Elements to be analyzed need to be in atomic state. Atomization is conversion of particles into individual molecules and breaking molecules into atoms .This is done by exposing the analyte to high temperatures in a flame or a flameless graphite furnace.

18. Flame: Flame AA can only analyze solutions , where it uses a slot type burner to increase the path length, resulting in increase in the total absorbance . Sample solutions are usually introduced into a nebuliser by a capillary tube. In the nebuliser the sample is dispersed into tiny droplets , which can be readily broken down in the flame to atoms. Air / Acetylene and N2O / Acetylene type flames are generally used depending on nature of analyte.

19. Nebuliser Capillary Solution Sample Introduction System

20. 4- Detector and Read out Device The light selected by the monochromator is directed on to a detector that is typically a photomultiplier tube , whose function is to convert the light signal into an electrical signal.

21. UV Spectrophotometer

22. PRINCIPLE OF UV/VIS SPECTROPHOTOMETER: When a monochromatic light is passed through a solution of any colour, it is absorbed Somewhat the magnitude of absorption depends on concentration of colour. Lambert-Beer's Law: Solution absorbance α concentration (at a certain limit)

23. Standard Curve, Calibration curve:

24. Different types of spectrophotometer are available depending on according and range. A simple photometer works in visible range. More sophisticated instruments have wide range and better precision. Components of UV/Visible Spectrophotometer:

25. Application: We use spectrophotometer to measure the concentration of different elements and compound in PPM and PPB level like Phosphate, Silica, Vanadium, DEA, Iron, Hydrazine etc. in various samples.

26. Karl Fisher Titration Karl Fisher titration is based on reaction between iodine and sulfur dioxide in an aqueous medium.

27. WORKING: Water and iodine are consumed in a 1:1 ratio in the above reaction. Once all of the water present is consumed, the presence of excess iodine is detected by double pin platinum electrode. . USES: Karl fisher titrator is used for the determination of water content in urea granules and lube oil samples . It can also be used for other materials like solvents, raw chemicals etc.

28. Conductivity Meter • Principle: • When two electrodes are immersed in a solution • and a potential is applied across them, a current • will be produced in the external circuit that • connects the two electrodes in the presence of • Ions. • Non.-ionic solutions cannot conduct electricity. • Conductivity is directly proportional to ionic Concentration. • Conductivity measures in mμ/cm

29. pH Meter pH meter is used to measure the acidity or alkalinity of aqueous samples pH meter can also be used as mV Meter electrometric titrations. It can be used as end point titrator as a substitute of pH indicator titration.

30. PARTS OF pH METER: Measuring device To Accurately measures and transforms the voltage into a pH value Sensing probe Generally called pH electrode to sense all the H+ions and to produce a potential.

31. Applications: Demin water, boiler’s water, Condensates , waste water effluents etc. are regularly checked for pH at our plant to maintain the quality of these waters. Generally combination pH electrode is used for its simplicity and ease of handling

32. Ion Selective Electrode ISE consist of the ion-selective membrane, an internal reference electrode, an external reference electrode, and a measuring device which is same as a pH meter.

33. Applications: • Ion-selective electrodes are used in a wide variety of applications for determining the concentrations of various ions in aqueous solutions. • Pollution Monitoring: CN, F, S, Cl, NO3 etc., in effluents, and natural waters. • In our laboratory we have different ion selective electrode for example • Fluoride ISE for measuring F in phosphoric acid • Chloride for measuring CL- contents in condensates, cooling water, CBD’s etc • Sodium for measuring Na+ contents in steam condensates etc.

34. Questions If Any ? THANK YOU