Swetanjali Naik Msc 2nd sem ppt (Gas Chromatography).pptx

Basics of Gas chromatography techniques.

1. GAS CHROMATOGRAPHY SUBMITTED BY:- Swetanjali Naik M.Sc. 3rd Sem SUBMITTED TO:- Dr. Sohini Bhattacharyya Mam Assistant Professor DEPARTMENT OF ZOOLOGY

2. CONTENTS:- INTRODUCTION WORKING PRINCIPLE INSTRUMENTATION APPLICATION ADVANTAGES DISADVANTAGES

3. Technique used for separation of compounds. GAS CHROMATOGRAPHY - Separating technique that separates and identifies components of a sample.  Based on their boiling points and by using gas as a mobile phase. TWO TYPES-GSC,GLC GAS –LIQUID CHROMATOGRAPHY: - MOBILE PHASE-gas, STATIONARY PHASE- liquid - liquid coated on inner support by adsorption or chemical bonding. Partition type of chromatography. GAS –SOLID CHROMATOGRAPHY:- MOBILE PHASE-gas, STATIONARY PHASE-solid Silica gel,alumina,charcole etc.used as solid. Used for separation of low molecular gases. INTRODUCTION:-

4. WORKING PRINCIPLE:- The principle of separation in GC is partition. Components that have a greater affinity with stationary phase spend more time in column and eluted later. They have a larger retention time than the samples that have a higher affinity for mobile phase. Components are separated according to their partition co-efficient. The components are eluted one another with their boiling point and then enter into the detector that attached to the exit end of the column. Here they register a series of signals from rates of elution on the recorder. Read out device study the graph and according to its height, width and area of peaks data can be measured.

5. INSTRUMENTATION:- 1.Carrier Gas reservoir- He,N2,H,Argon(mobile phase) Main purpose is to move the solutes along the column. Carrier gas should be Inert, suitable for detector, easily available ,free from fire explosion hazards. 2.Pressure Regulator- Control the pressure of gas. 3.Sample injection port- Liquid sample is injected by a micro syringe. Injected through a rubber septum. Due to temperature liquid sample is converted to vapors.

6. .Chromatographic column- ​ Made up of stainless still or glass ,2-3 meter long, daimeter is 2-4mm. ​ Packed column- packed with solid as absorbent in GSC. ​ Capillary column- stationary phase coated on the inner wall. ​ -WCOT column, SCOT column ​, PLOT column Solid stationary phase -alumina, silica gel. Liquid stationary phase -paraffin oil, silicone oil etc. ​ 5.Oven- used to heat the sample due to which separation occurs. ​ 6.Detectors:- detect the eluted components and their flow rate. Detectors must have good sensitivity, stability, selectivity etc. ​ TYPES-TCD,FID,ECD 7.RECORDER-   used to record the response obtained from the detectors after amplification .

7. APPLICATION- Used in Food analysis. Helps in the detection of contaminants. quality control. Used in chemical and pesticides producing companies. Majorly used in pharmaceutical field. Used by automobile industry. Uses for analyzing compounds to check for trace contaminants. It is used for research purposes and for analyzing of natural products. Lots uses in forensic field. Used to determining the circumstances of persons death. Measuring air pollution. Used to determine blood-alcohol level.

8. ADVANTAGES:- 1.Versatility 2.Robustness 3.Complementary with other techniques 4.Reliability 5.Diverse sample analysis 6.Sensitive detection 7.High accuracy 8.High resolution power compared to other methods. 9.Non -destructive method 10.Good separation 11.Quantitative analysis and qualitative analysis

9. DISADVANTAGES:- Limited to volatile compounds. Non-volatile compounds don’t vaporize. Analyte can decompose at high temperature and react with stationary phase. It is limited to molecular weight. Thermal stability is required. Not suitable for high boiling compounds.

10. THANK YOU