งานนำเสนอกำลังจะดาวน์โหลด โปรดรอ

งานนำเสนอกำลังจะดาวน์โหลด โปรดรอ

1 INTRODUCTION TO GAS CHROMATOGRAPHY. 2 GC is a technique used to separate, identify and quantify compounds in a sample mixture. Compounds are separated.

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งานนำเสนอเรื่อง: "1 INTRODUCTION TO GAS CHROMATOGRAPHY. 2 GC is a technique used to separate, identify and quantify compounds in a sample mixture. Compounds are separated."— ใบสำเนางานนำเสนอ:

1 1 INTRODUCTION TO GAS CHROMATOGRAPHY

2 2 GC is a technique used to separate, identify and quantify compounds in a sample mixture. Compounds are separated primarily by differences in their volatilities and structures. Compounds must vaporize into the gas phase below C and thermally stable. GAS CHROMATOGRAPHY (GC)

3 How the GC Operating? InjectionMigration Elution Peak Signal Flow Controller Injection Port Column Oven Detector Column Recorder/Data System Carrier Gas Chromatogram Column Operating

4 GC ? ● GC : Gas Chromatography ● Is an Analytical Instruments Technique used for Separating Chemical Mixtures ● Column coated with non-Volatile is a Stationary Phase ● Solutes are Carried through GC dissolved in Carrier gas is a Mobile Phase ● Solutes must be in vapor state at GC Operating Temperature

5 GAS CHROMATOGRAPHY เหมาะกับตัวอย่างที่กลายเป็นไอได้ง่าย (volatility) และมีความเสถียรทางความร้อน (thermal stability) สารผสมถูกแยกออกจากกันเนื่องจากความ แตกต่างทางคุณสมบัติทางฟิสิกส์หรือทาง เคมี ใช้ก๊าซเฉื่อย (inert gas) เป็นก๊าซพา (carrier gas)

6 หลักการของ Chromatography เป็นเทคนิคการวิเคราะห์ที่ใช้สำหรับการแยกสาร ผสม  การแบ่งส่วน (partitioning) ระหว่าง mobile phase และ stationary phase นำไปสู่การแยก  GC ใช้ก๊าซเฉื่อยเป็น mobile phase และใช้ของเหลวซึ่ง กลายเป็นไอได้ยาก มีน้ำหนักโมเลกุลสูง เป็น stationary phase Chromatogram ถูกนำไปใช้เพื่อช่วยในการพิสูจน์ เอกลักษณ์ของสารและการวิเคราะห์หาปริมาณ องค์ประกอบต่างๆในตัวอย่าง

7 7 time (A) (B) (D) (C) SEPARATION OF SAMPLE IN THE COLUMN

8 8 Chromatography is a separation method achieved by the distribution of substances between two phases: a mobile phase and a stationary phase. Mobile Phase Stationary Phase Gas Solid Chromatography Gas Solid (GSC) Gas Liquid Chromatography Gas Liquid (GLC) HOW SEPARATION OCCURS

9 SAMPLE INTRODUCTION COLUMN OVEN DETECTOR TEMPERATURE CONTROL DATA SYSTEM GAS SUPPLY DATA OUTPUT CHROMATOGRAM GAS CHROMATOGRAPH

10 10 chosen with the consideration of the type of detector used Carrier Gas: He, N 2, H 2  Inert  Dry  Pure CARRIER AND DETECTOR GASES

11 Gas for GC Non Flammable Detector ECD,TCD Flammable Detector FID,FPD,TSD Carrier Gas is He,N2,H2,Argon purity UHP > Fuel = H2 purity UHP > Oxidation = Air purity UHP > Carrier2.Fuel& 3.Oxidation

12 การเลือกก๊าซพา (Carrier Gas) มีคุณสมบัติเฉื่อย (inert) ปราศจากความชื้น และ บริสุทธิ์ ( มีสิ่งปนเปื้อน <1 ppm) H 2 เร็วที่สุดมีความหนืดต่ำที่สุด แต่ไม่เหมาะกับ GC/MS เนื่องจาก ยากต่อกับขับออกด้วย vacuum pumping system N 2 ดีกว่า H 2 และ He เล็กน้อยที่ optimum carrier gas flow rate สำหรับ fast analysis: H 2 ดีกว่า He และ He ดีกว่า N 2 คำนึงถึงเครื่องตรวจวัดที่ใช้ ใช้ He เป็นก๊าซพาใน GC/MS

13 Gas Filters Gas Filters & Accessories

14 Gas-Clean Filters Using high-grade gases in analytical labs is considered critical for modern high-resolution gas chromatography Leaks in the gas lines connecting the gas cylinders to the GC are sometimes inevitable. Oxygen, water moistures, hydrocarbons may enter into your GC system may result in  damage to column  loss of sensitivity  damage to detector High sensitivity indicators Fast and simple replacement  No instrument down time  No tools required Will fit the filter base of Agilent, SGE and Alltech

15 15 Purpose: To introduce the sample on to the column in the vapor state. Syringe Injection Manual injection Auto-sampler injection Valve Injection Gas sampling valves Liquid sampling valves Auxiliary Sampling Devices Purge and Trap Headspace Sample Introduction

16 16 Packed column inlet Septum - purged packed column inlet Split/splitless capillary inlet Split - only capillary inlet Dedicated on - column capillary inlet TYPES OF INLET SYSTEMS

17 17 carrier gas line liner o-ring liner septum nut septum column column nut and ferrule split vent flow controller or pressure regulator 1 mL/min 98 mL/min 2 mL/min 97 mL/min 100 mL/min flow controller or needle valve pressure regulator or needle valve SPLIT INJECTOR BASIC VAPORIZATION INJECTOR

18 18 1 mL/min 28 mL/min 2 mL/min 27 mL/min 30 mL/min septum purge vent 1 mL/min 1 mL/min 2 mL/min 0 mL/min 3 mL/min flow controller or needle valve split vent solenoil-open solenoil-closed PURGE OFF PURGE ON flow controller or pressure regulator or needle valve

19 19 Ratio of amount of sample in the column and total sample split ratio = F column + F split vent / F column Ratio of amount of sample in the column and the amount leaving via the split line split ratio = F split vent / F column F split vent = Flow from split vent (mL/min) F column = Column flow (mL/min)

20 Wall Coated Open Tube Porous Layer Open Tube Bead Column Porous Layer Bead 0pen (Capillary) Packed Regular Conventional Packed and Micro Packed COLUMN TYPES

21 Pack Column

22 Capillary Column GC Column

23

24 Type of Column FSOT WCOT SCOT Packed Length, m Inside diameter,mm Efficiency, plates/m Sample size,ng Relative pressure Low Low Low High Relative speed Fast Fast Fast Slow Chemical inertnessBest Poorest Flexible Yes No No No FSOT : Fused-silica, open tubular column. WCOT : Wall-coated, open tubular column. SCOT : Support-coated, open tubular column. Properties and Characteristics of Typical GC Columns

25 25 Efficiency : Ability of the column to produce sharp peaks. Resolution : Ability of the column to separate two peaks from each other. Selectivity : Ability of the column to determine chemical and/ or physical difference in two peaks. COLUMN SEPARATION CHARACTERISTICS

26 26 Efficiency Resolution Selectivity Efficiency Resolution Selectivity COLUMN SEPARATION CHARACTERISTICS

27 27 ISOTHERMAL TEMPERATURE PROGRAMMED COLUMN SEPARATION CHARACTERISTICS

28 28 COLUMN TEMPERATURE OPERATION ISOTHERMAL TEMPERATUREPROGRAMMED

29 29 Definition : A GC Detector is a device which senses the presence of a component different from the carrier gas, and converts that information to an electrical signal. GC DETECTOR

30 30 Sensitivity: The response per amount of sample, that is, the slope of the response / amount curve. The minimum amount on the curve is defined as the minimum detectable level (MDL). Selectivity: A measure of which categories of compounds will give a detector response. Dynamic Range : The range of sample concentrations for which the detector can provide accurate quantitation. DETECTOR RESPONSE CHARACTERISTICS

31 31 Thermal Conductivity Detector (TCD) Flame lonization Detector (FID) Electron Capture Detector (ECD) Nitrogen Phosphorus Detector (NPD) Flame Photometric Detector (FPD) Photo-ionization Detector (PID) Electrolytic Conductivity Detector (ELCD,HALL) Mass Selective Detector (MSD) Infrared Detector (IRD) GC DETECTOR

32 Types of DetectorsBrief Description TCDFilament temperature increases as analytes present in the carrier gas pass over it. Causing the resistance to increase. FID Components burn in a flame producing ions which are collected and converted into a current ECD As electronegative species pass through the detector, they capture low energy thermal electrons causing a decrease in cell current. Detectors

33 Types of DetectorsBrief Description NPDNitrogen and phosphorous compounds produce increased currents in a flame enriched with vaporized alkali metal salt. FPD Sulfur and phosphorous compounds burn in a flame producing chemiluminescent species which are monitored at selective wave lengths.. Detectors

34 Types of DetectorsBrief Description ELCDHalogens, sulfur, or nitrogen compounds are mixed with a reaction gas in a reaction tube. The products are mixed with a suitable liquid which produces a conductive solution PIDMolecule are ionized by excitation with photons from a UV lamp. The charged particles are then collected, producing a current. Detectors

35 Types of DetectorsBrief Description MSDMolecules are bombarded with electrons producing ion fragments which pass into the spectrometers mass filter. The ions are filtered based on their mass / charge ratio. IRDMolecules absorb infrared energy, the frequencies of which are characteristic of the bonds within that molecule. Detectors

36 Types of DetectorsBrief Description AEDMolecules are energized by a plasma source and separated into excited atoms. As electrons return to their stable state, they emit light,which is element specific. Detectors

37 TypeTypicalSensitivity Carrier+ SamplesRange Makeup H 2 Air FIDHydrocarbons1 - 5 pgC/s ppb - 99 % TCDGeneral ng n.a. n.a. 10ppm - 100% ECDOrganohalogens pg n.a. n.a. Chlorinated 50ppt-1ppm solvents & pesticides DETECTORS COMMONLY USED IN CAPILLARY GC

38 TypeTypicalSensitivity Carrier+ SamplesRange Makeup H 2 Air NPDOrganonitrogen pg &organo 100ppt-0.1% phosphorus compounds FPDSulfur pg (393 nm) compounds 10ppb-00ppm FPDPhosphorus1-10 pg (526nm )compounds1ppb-0.1% DETECTORS COMMONLY USED IN CAPILLARY GC

39 TypeTypicalSensitivity Carrier+ SamplesRange Makeup H 2 Air PIDCompounds 2pg C/sec * n.a. ionized by UV ELCDHalogens,N,S0.5pg CI/sec n.a. 2pg S/sec 4pg N/ sec FTIRMolecular 1000pg of 3-10 n.a. n.a. vibrations Strong absorber DETECTORS COMMONLY USED IN CAPILLARY GC

40 TypeTypical Sensitivity Carrier+ Samples RangeMakeup H 2 Air MSDTunable for any10pg to 10 ng ** n.a. n.a. species(depending on SIM vs.Scan) AEDTunable for any0.1-20pg/sec PRESET PRESET Element(depending on element) * Refer to Detector Manual ** Dependent upon the type of interface DETECTORS COMMONLY USED IN CAPILLARY GC

41 APPLICATION Qualitative Analysis Quantitative Analysis

42 Qualitative Analysis Comparision of retention data  relative retention  retention indices

43 Quantitative Analysis Area % Normolization % External standard Internal standard

44 Area % of A = Area(A)/S Area Area % of A=280/1070=26.17 AREA %

45 RF=amount/area NORM%=(RF*area)*100/S(RF* area) NORMALIZATION %

46 Calibration External standard

47 Calibration External standard

48 Calibration curve : compound A Concentration( m g /ml) area concentration area

49 Calibration curve : compound B Concentration( m g /ml) area concentration area

50 Calibration curve : compound C Concentration( m g /ml) area concentration area

51 Sample External standard

52 Calibration Internal standard

53 Calibration Internal standard

54 Concentration Area ratio m g/mlA B C COMPOUND A Area ratio Concentration Calibration curve

55 Internal standard COMPOUND C Area ratio Concentration Calibration curve Concentration Area ratio m g/mlA B C

56 Sample Internal standard

57 Summary Of Methods ADVANTAGES DISADVANTAGES AREA %No calibration required Must have uniform Injection size not critical detector response All components must elute All components must be detected

58 Summary Of Methods ADVANTAGES DISADVANTAGES NORM % Injection size not critical All peaks must elute All peaks must be measured Must calibrate all peaks

59 Summary Of Methods ADVANTAGES DISADVANTAGES ESTDCorrect for detector response Injection size is critical Calibrate peaks of interest Instrument stability required Not all peaks need elute Frequent recalibrations Not all peaks need detect Results reported in units of choice

60 Summary Of Methods ADVANTAGES DISADVANTAGES ISTD Known component addaded Must add a component to both sample and standard to the sample Injection size not criticalMore complex sample Calibrate peaks of interest and standard preparation Correct for detector response steps Results reported in units of choice

61 61 Column type, stationary phase Condition: temperature, flow rate Carrier gas Detector Injection volume Sample CHROMATOGRAM


ดาวน์โหลด ppt 1 INTRODUCTION TO GAS CHROMATOGRAPHY. 2 GC is a technique used to separate, identify and quantify compounds in a sample mixture. Compounds are separated.

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