Chromatography
description
Transcript of Chromatography
Created by Nick Buker 12/18/08
Chromatography
Created by Nick Buker 12/18/08
Chromatography
Merupakan teknik yg digunakan untuk memisahkan dan mengidentifikasi komponen dari suatu campuran .
Molekul yg ada dalam campuran didistribusikan masing-masing diantara medium stasioner dan mobile.
Molekul yg paling lama di fase gerak lebih cepat mengalir
Created by Nick Buker 12/18/08
• Metode pemisahan campuran molekul tergantung pada distribusinya diantara fase gerak dan fase diam
• Fase gerak (juga disebut sebagai pelarut ) bisa berupa cairan atau gas.
• Fase diam (juga disebut sebagai sorbent) dapat berupa padatan atau cairan, fase diam is held stationary oleh suatu padatan.
• Padatan yg mempertahankan fase diam cair merupakan matrik support.
• Molekul-molekul dalam kondisi tercampur yg dapat dipisahkan disebut solut.
Created by Nick Buker 12/18/08
Apa itu Chromatography?
Fase diam
Fase gerak
Chromatography: metode pemisahan yg kuat yg biasanya terdiri dari fase gerak dan fase diam
Elusi
Sampel
Sampel dipisahkan pada kolom berdasar perbedaan dalam interaksi molekuler dari jenis molekul analit yg berbeda dengan fase gerak dan fase diam
Kolom
Created by Nick Buker 12/18/08
Bagaimana Chromatography Bekerja
• Fase Diam/stasioner – Padatan tidak bergerak • Fase Gerak – Larutan yg bergerak
Created by Nick Buker 12/18/08
Chromatography dan sungai
• Dua kelompok orang yg terbawa arus sungai :– Kelompok kuat akan berpegangan di batu – Kelompok lemah akan terbawa arus sungai lebih
cepat
Created by Nick Buker 12/18/08
Perenang dan molekul
• Kemampuan berpegangan ke batu akan mengontrol kecepatan perenang terbawa arus sungai
• Kemampuan berinteraksi ke padatan di fase stasioner akan mengontrol kecepatan molekul terbawa pelarut
Chromatography Kolom
Chromatogram
Dilution &Peak broadening!
Chromatography: Pemisahan puncak
Chromatography: Resolusi puncak
Resolution jelek
More separation
Lass band spread
Chromatography Resolusi
Created by Nick Buker 12/18/08
RESOLUSI
Created by Nick Buker 12/18/08
Created by Nick Buker 12/18/08
Retention Time
Waktu yg diperlukan bagi sampel untuk bergerak dari bagian injeksi melewati kolom menuju detektor .
Response
Retention Time5 10 15 20 25
A
B
C
D
Chromatography Retention Times
tM = retention time fase gerak (dead time)
tR = retention time analit (solute)L = panjang kolom
Created by Nick Buker 12/18/08
Ekpresi hasil
• Istilah "Rf" (relative flow) digunakan untuk mengekspresikan performance suatu solute dalam suatu solvent system /support medium. Istilah nilai Rf didefinisikan sbg jarak komponen mengalami migrasi dengan jarak migrasi pelarut. Nilai Rf konstan untuk komponen tertentu, sistem pelarut dan matrik tidak terlarut.
Rf= Jarak migrasi solute
Jarak pergerakan solvent
Created by Nick Buker 12/18/08
Definition:
Different affinity of these 2 components to stationary phase causes the separation.
Concentration of component A in stationary phase
Concentration of component A in mobile phase
Distribution Coefficient (Equilibrium Distribution )
Created by Nick Buker 12/18/08
Pemisahan senyawa dg chromatography tergantung pada beberapa faktor :
• Partisi suatu solute diantara pergerakan fase pelarut dan fase cair stasioner.
• Solute bergerak sesuai aliran pelarut pada kecepatan yg ditentukan oleh kelarutan solute dalam fase bergerak.
• Jadi, komponen dg mobilitas tinggi lebih terikat ke fase organik bergerak daripada fase diam.
Created by Nick Buker 12/18/08
Cont..
• Pengaruh Ion exchange : Banyak impuritas terion dalam support medium akan cenderung mengikat atau tertarik ion yg bermuatan berbalikan (solutes) dan oleh karena itu akan mengurangi mobilitas solut tersebut.
• Suhu : Juga merupakan faktor penting,• Karena suhu dapat mempengaruhi
kelarutan solut dalam suhu.
Created by Nick Buker 12/18/08
Cont..
• Berat molekul solute juga mempengaruhi kelarutan sehingga mempengaruhi performance chromatographic .
• Adsorpsi komponen (solute) ke support medium: Jika solut cenderung mengikat support medium, hal ini akan memperlambat mobilitasnya dalam solvent system.
Created by Nick Buker 12/18/08
Cont..
• Komposisi solvent: karena banyak komponen yg lebih larut dalam suatu pelarut daripada pelarut lainnya, campuran pelarut yg digunakan akan mempengaruhi pemisahan komponen.
Created by Nick Buker 12/18/08
Structur molekuler dan Polaritas
• Struktur Molekular mempengaruhi kecepatan• Polaritas bertanggung jawab thd interaksi • Polaritas Molekular dibangkitkan oleh area muatan
C
CC
C
CC C
O
O
O
COH3C
H
H
H
H
H
Aspirin (acetylsalicylic acid)
C
CC
C
CC
CH2
CH
CH3
H3C
CH
H
C
O
OH
H
H
H
H
Advil (ibuprofen)
Created by Nick Buker 12/18/08
PELARUT
Pelarut Polar
Water > Methanol > Acetonitrile > Ethanol > Oxydipropionitrile
Pelarut Non-polar
N-Decane > N-Hexane > N-Pentane > Cyclohexane
Created by Nick Buker 12/18/08
Jenis chromatography
• Chromatography Partisi• Chromatography Adsorbsi• Gel filtrasi• Ion exchange chromatography
Created by Nick Buker 12/18/08
MOBILE PHASE LIQUID
Liquid-LiquidChromatography (Partition)
Liquid-SolidChromatography (Adsorption)
Liquid Solid
Normal Phase Reverse Phase Normal Phase Reverse Phase
Mobile Phase - NonpolarStationary phase - Polar
Mobile Phase - PolarStationary phase - Nonpolar
FORMAT
STATIONARYPHASE
Jenis Chromatography
Chromatography
Created by Nick Buker 12/18/08
Chromatography Partisi
• Distribusi terlarut diantara 2 fase yg berbeda polaritasnya.
• Solute akan diditribusi dg sendirinya diantara 2 fase berdasarkan kelarutannya dalam masing-masing fase, hal ini disebut partisi.
Created by Nick Buker 12/18/08
Contoh chromatography partisi
• Dua jenis chromatography partisi yg paling umum adalah thin layer chromatography/TLC dan chromatography kertas.
• Fase stasioner kedua jenis tersebut merupakan cairan yang terikat ke suatu matrik.
• Pada chromatography kertas, fase stationary merupakan molekul air yang terikat ke matrik selulosa.
Created by Nick Buker 12/18/08
• Pada TLC, Fase diamnya berupa pelarut yg ditambahkan ke support untuk membentuk lapisan tipis sehingga pelarut dapat terikat ke matrik (support).
• Chromatography partisi utamanya digunakan untuk pemisahan molekul dengan berat molekul kecil .
Created by Nick Buker 12/18/08
Chromatography kertas
• Support sellulosa mengandung air terikat dalam jumlah banyak.
• Partitioning terjadi diantara air terikat yg berfungsi sbg fase diamnya dan pelarut merupakan fase geraknya.
Created by Nick Buker 12/18/08
Deteksi spot
• Spots pada kertas kromatogram dapat dideteksi dengan 4 cara:
1.Melalui warna alaminya 2.Melalui fluorescencenya3.Melalui reaksi kimia yg terjadi setelah kertas
dapat dispray dg berbagai reagent sbg contoh: selama paper chromatography amino acids, kromatogram dispray dg ninhydrin.
4.Melalui radioaktifitas
Created by Nick Buker 12/18/08
Identifikasi spot
• Spots biasanya diidentifikasi melalui perbandingan standart yg diketahui sbg nilai Rf .
Created by Nick Buker 12/18/08
Thin layer chromatography
• Dalam TLC, beberapa senyawa yg dapat dipisah dengan baik dan dibentuk menjadi lapisan seragam .
• Baik senyawa organik maupun anorganik dapat digunakan untuk membentuk lapisan seragam untuk TLC.
• Senyawa organik meliputi: cellulose, polyamide, polyethylene
• Anorganik : silica gel, aluminum oxide and magnesium silicate
Created by Nick Buker 12/18/08
TLC
• Fase diamnya berupa pelarut yg digunakan untuk membentuk lapisan sorbent disebar seragam diatas permukaan plate plastik atau kaca
Created by Nick Buker 12/18/08
TLC
Fase gerak berupa cairan
Aliran sampel terjadi pada thin layer pada solid support.
Substansi yg kurang tertarik ke padatan atau lebih larut dalam cairan bergerak lebih cepat
Created by Nick Buker 12/18/08
Created by Nick Buker 12/18/08
TLC
Fase diam ---------> Silica Gel
Fase gerak -------------> pelarut
Created by Nick Buker 12/18/08
SOLVENT
SPOT
DEVELOPINGCHAMBER
Origin
SolventFront
1.1 cm
5.5 cm
Rf =Distance from starting origin to center of zone
Distance from starting origin to solvent front
= 5.5
11= 0.5
TLC
Created by Nick Buker 12/18/08
Kelebihan TLC dibanding paper chromatography
• Resolving power lebih besar karena adanya difusi spot yg lebih rendah.
• Kecepatan pemisahan lebih tinggi • Pilihan bahan sbg sorbents lebih banyak
Created by Nick Buker 12/18/08
LIQUID COLUMN CHROMATOGRAPHY
Campuran sampel melewati suatu kolom yang dilapisi dengan partikel padat yang dapat atau tidak dapat di coating dengan cairan lainnya .
Dengan pelarut yg sesuai, kondisi pengemasan, beberapa komponen dalam sampel akan bergerak menuju kolom lebih lambat daripada lainnya yang menghasilkan pemisahan sesuai dengan keinginan.
Created by Nick Buker 12/18/08
Schematic Diagram of Liquid Chromatography
Created by Nick Buker 12/18/08
A + B + C O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
Sampl e (A+ B+ C)
Col umn
Sol i d Part i cl es(packi ng mater i al - st at i onary phase)
El uant ( el uate)
D I A G R A M O F SIMPLE LI Q U ID CO LU MN CH R O MATO G R A PH Y
A
B
C
Sol vent ( mobi l e or movi ng phase)
Diagram of Simple Liquid Column Chromatography
Created by Nick Buker 12/18/08
4 dasar model liquid chromatography dinamakan sesuai dengan mekanisme yg digunakan :
1. Liquid/Solid Chromatography ( chromatography adsorpsi)
A. Normal Phase LSC
B. Reverse Phase LSC
2. Liquid/Liquid Chromatography ( chromatography partisi)
A. Normal Phase LLC
B. Reverse Phase LLC
3. Ion Exchange Chromatography
4. Gel Permeation Chromatography ( chromatography exclusi)
EMPAT DASAR LIQUID CHROMATOGRAPHY
Created by Nick Buker 12/18/08
LIQUID SOLID CHROMATOGRAPHY
Si - O - H
Normal phase LS Reverse phase LS
Silica Gel
Mekanisme pemisahan dalam LSC didasarkan pada kompetisi komponen dari campuran sampel bagi sisi aktif pada absorbent seperti Silica Gel.
Created by Nick Buker 12/18/08
LIQUID SOLID CHROMATOGRAPHY
Si - OH
HEXANE
OH
C-CH3
CH3
CH3- CCH3
CH3
OH
OH
CH3
CH3
Created by Nick Buker 12/18/08
VITAMINS LARUT AIR
1. Niacinamide 2. Pyridoxine
N
CONH2
N
CH2OHCH2OH
HO
H3C
3. Riboflavin
N
NNH
NCH2
HOCHHOCHHOCH
CH2OH
O
OH3C
H3C
ClN
S
N
NH3C
CH2
NH2
CH3
CH2CH2OH
4. Thiamin
Created by Nick Buker 12/18/08
VITAMINS LARUT AIR
0 5 10 15 20
Column: u Bondapak C18 Solvent: MeOH Sample: Water-Soluble Vitamins
Inject1
2
3
4
Created by Nick Buker 12/18/08
LIQUID-LIQUID CHROMATOGRAPHY
ODPN(oxydipropionylnitrile)
Normal Phase LLC Reverse Phase LLC
NCCH3CH2OCH2CH2CN(Normal)CH3(CH2)16 CH3 (Reverse)
Permukaan padatan diam dilapisi dengan pelarut kedua (fase diam) yg immiscible dalam pelarut (fase gerak). Partisi sampel diantara 2 fase menunda atau mempertahankan beberapa komponen daripada komponen lainnya untuk mempengaruhi pemisahan.
Created by Nick Buker 12/18/08
Pembuat Gradient
Created by Nick Buker 12/18/08
Bahan Reversed phase
Created by Nick Buker 12/18/08
Prinsip RP
Created by Nick Buker 12/18/08
ION-EXCHANGE CHROMATOGRAPHY SO3
- Na+
Pemisahan Ion-exchange Chromatography didasarkan pada kompetisi komponen ionik yg berbeda dari suatu sampel bagi sisi aktif di ion-exchange resin (column-packing).
Created by Nick Buker 12/18/08
MEKANISME ION-EXCHANGE CHROMATOGRAPHY DARI ASAM AMINO
SO3-
SO3-
Na+
COO-
H3N+
Na+
COOHH3N
+
pH2
pH4.5
Ion-exchange Resin
Created by Nick Buker 12/18/08
H3N+
S O3-
S O3-
S O3-
S O3-
S O3-
S O3-
H3N+
COOH
OH
COOH
COOHH3N+
H3N+OH
COO-Na+
H3N+
COO-
Na+
Na+
H+ OH- = H2O
H+ OH- = H2O
Na+
Na+
pH3.5
M obile Phas eStationary Phas e
Exc hange Res in
pH4.5
Chromatography Asam Amino
Created by Nick Buker 12/18/08
Ion exchange
Created by Nick Buker 12/18/08
CM and DEAE
Created by Nick Buker 12/18/08
Jenis ion exchange
Created by Nick Buker 12/18/08
Stepwise elution for ion exchange
Created by Nick Buker 12/18/08
GEL-PERMEATION CHROMATOGRAPHY
Gel-Permeation Chromatography merupakan suatu mekanisme sorting molekul-molekul berdasarkan ukuran molekul dalam larutan . Molekul kecil dapat melewati/ permeate lebih more pores , oleh karena itu, dipertahankan lebih lama daripada molekul besar.
Created by Nick Buker 12/18/08
Gel filtration
Created by Nick Buker 12/18/08
Gel filtration
Created by Nick Buker 12/18/08
Gel filtration
Created by Nick Buker 12/18/08
350 min on 60 cm 75 micron ID 3.5 beads 100 nl/min
Created by Nick Buker 12/18/08
SPPVGPAL
TIC
MS
MS/MS
Created by Nick Buker 12/18/08
LC-MS display of differently expressed proteins
Differently expressed peptide
TimeTime
M/Z
Created by Nick Buker 12/18/08
Gas Liquid Chromatography
Fase geraknya berupa gas yang tdk reaktif (seperti Nitrogen) yg mengalir melalui suatu tabung
Dan fase diamnya berupa liquid tidak volatil held on particles of a solid support.
Prinsip
Partisi molekul diantara gas (fase gerak) dan cairan (fase diam ).
Created by Nick Buker 12/18/08
Fase Diam yg paling umum
1. Pemisahan campuran komponen polar Carbowax 20M (polyethylene glycol)
2. Pemisahan campuran komponen non polarOV101 or SE-30 (polymer of methylsilicone)
3. Methylester dari asam lemak DEGS (diethylene glycol succinate)
Created by Nick Buker 12/18/08
Pada animasi dibawah ini molekul yg berwarna merah lebih mudah larut dalam cairan (atau kurang volatil) daripada molekul yg berwarna hijau.
Created by Nick Buker 12/18/08
In practice the Column is contained in a thermostatic oven. (Why ?)
About 1μL of liquid is injected into one end of the column.
As each component reaches the other end it is detected and registered on a chart recorder.
The Retention Time is characteristic of a particular substance. (for the same column, temperature, gas flow etc.)
The area under each peak indicates the relative quantities.
Created by Nick Buker 12/18/08
Oven
Detector
Injection port
Nitrogen cylinder
Column
Recorder
Created by Nick Buker 12/18/08
Created by Nick Buker 12/18/08
Chromatogram of petrol
Suggest identities of some of the unlabelled peaks.
Created by Nick Buker 12/18/08
Filters/Traps
Air
Hydrogen
Gas C
arrier
Column
Gas Chromatography
• gas system
• inlet• column• detector• data
system
Data system
Syringe/Sampler
Inlets
Detectors
Regulators
H
RESET
Created by Nick Buker 12/18/08
Skema Diagram Gas Chromatography
Created by Nick Buker 12/18/08
Skema Diagram Gas Chromatography
Created by Nick Buker 12/18/08
DETEKTOR
Flame Ionization Detector (Nanogram - ng)
High temperature of hydrogen flame (H2 +O2 + N2) ionizes compounds eluted from column into flame. The ions collected on collector or electrode and were recorded on recorder due to electric current.
Created by Nick Buker 12/18/08
Exhaust
ChimneyIgniter
Hydrogen Inlet
Column Effluent
Polarizing ElectrodeCollector Electrode
Skema Diagram Flame Ionization Detector
Created by Nick Buker 12/18/08
Skema Diagram Flame Ionization Detector
Collector
Jet
Flame
Detector electronics
- 220 volts
Column
Chassis ground
Signal output
Created by Nick Buker 12/18/08
Thermal Conductivity Detector
Mengukur perubahan konduktifitas thermal berkaitan dengan sampel (g). Sampel dapat direcovery.
Created by Nick Buker 12/18/08
Detektor Konduktifitas Thermal
Principal: The thermal balance of a heated filament
Electrical power is converted to heat in a resistant filament and the temperature will climb until heat power loss form the filament equals the electrical power input.
The filament may loose heat by radiation to a cooler surface and by conduction to the molecules coming into contact with it.
Created by Nick Buker 12/18/08
Dasar Konduktifitas Thermal
When the carrier gas is contaminated by sample , the cooling effect of the gas changes. The difference in cooling is used to generate the detector signal.
The TCD is a nondestructive, concentration sensing detector. A heated filament is cooled by the flow of carrier gas .
Flow
Flow
Created by Nick Buker 12/18/08
When a compound elutes, the thermal conductivity of the gaseous mixture of carrier gas and compound gas is lowered, and the filament in the sample column becomes hotter than the other control column.
Its resistance increased, and this imbalance between control and sample filament resistances is measured by a simple gadget and a signal is recorded
Detektor Konduktifitas Thermal
Created by Nick Buker 12/18/08
Konduktifitas Thermal Relative
Compound Relative Thermal Conductivity
Carbon Tetrachloride 0.05Benzene 0.11Hexane 0.12Argon 0.12Methanol 0.13Nitrogen 0.17Helium 1.00Hydrogen 1.28
Created by Nick Buker 12/18/08
• Responds to all compounds• Adequate sensitivity for many compounds • Good linear range of signal• Simple construction• Signal quite stable provided carrier gas glow rate,
block temperature, and filament power are controlled• Nondestructive detection
Detektor Konduktifitas Thermal
Created by Nick Buker 12/18/08
Detektor Electron Capture
For pesticide analysis (picogram).
Accept electrons of carrier gas.
Created by Nick Buker 12/18/08
Detektor Electron CaptureECD detects ions in the exiting from the gas chromatographic
column by the anode electrode.3H or 63Ni which emits particles.
Ionization : N2 (Nitrogen carrier gas) + (e) = N2+ + 2e
These N2+ establish a “base line”
X (F, Cl and Br) containing sample + (e) X-
Ion recombination : X- + N2+ = X + N2
The “base line” will decrease and this decrease constitutes the signal.
Insecticides, pesticides, vinyl chloride, and fluorocarbons
Created by Nick Buker 12/18/08
Detektor Electron Capture
Created by Nick Buker 12/18/08
Detektor Electron Capture
Created by Nick Buker 12/18/08
Gas Chromatography Application
Created by Nick Buker 12/18/08
ANALYSIS ASAM LEMAK SEMI- QUANTITATIVE
C
C
CDetector Response
Retention Time
14
16
18Peak Area (cm )
Sample Concentration (mg/ml)
2
4
6
8
10
0.5 1.0 1.5 2.0 2.5 3.0
2
The content % of C fatty acids =C
C + C + C
= the content % of C fatty acids14
14
Created by Nick Buker 12/18/08
IDENTIFIKASI KOMPNEN YG TDK DIKETAHUI TENTATIVE
Response
GC Retention Time on Carbowax-20 (min)
Mixture of known compounds
Hexane
Octane Decane1.6 min = RT
Response
Unknown compound may be Hexane
1.6 min = RT
Retention Time on Carbowax-20 (min)
Created by Nick Buker 12/18/08
Response
GC Retention Time on SE-30
Unknown compound
RT= 4 min on SE-30
Response
GC Retention Time on SE-30
Hexane
RT= 4.0 min on SE-30
Retention Times
Created by Nick Buker 12/18/08
KELEBIHAN GLC
1. Pemisahan sangat baik
2. Waktu (analysis singkat )
3. Membutuhkan sampel sedikit - l
4. Sistem deteksi bagus
5. Analisis Quantitativ
Created by Nick Buker 12/18/08
KEKURANGAN GAS CHROMATOGRAPHY
Bahan harus dibuat volatil pada suhu 250C tanpa terjadi dekomposisi .
R C OH CH3OH H2S O4
O
R C O CH3
O
CH2 O C R
CH O C R
CH2 O C R
O
O
O
CH3OH
O
R C O CH3
CH3ONa
Fatty Ac ids M ethyles ter
Reflux
+ 3
Volatile in Gas Chromatography
Volatile in Gas Chromatography
+ +
Created by Nick Buker 12/18/08
Gas Chromatogram of Methyl Esters of Fatty Acids
Created by Nick Buker 12/18/08
The Effects of OH groups of Carbohydrates
OH
O
OH
OHHO
CH2OH
1
23
45
6
OH
O
OH
OHHO
CH2OH
1
23
45
6
Created by Nick Buker 12/18/08
OH
O
OH
OHHO
CH2OH
1
23
45
6
+ Si
CH3
CH3
CH35Cl
O-Si(CH3)3
O
O-Si(CH3)3
O-Si(CH3)3(CH3)3-Si-O
CH2O-Si(CH3)3
1
23
45
6
5HCl+
Derivation of Glucose with Trimethylchlorosilane
Glucose Trimethylchlorosilane
Created by Nick Buker 12/18/08
Pengaruh Derivatisasi
1. Butuh waktu
2. Reaksi samping
3. Kehilangan sampel
Created by Nick Buker 12/18/08
The detector contains two filaments: one exposed only to carrier gas, while the other is exposed to the carrier gas for sample analysis.
When the gas for the sample analysis is only carrier gas , the two filaments can be balanced.
Instead of a direct measurement of filament temperature, the filament resistant, which is a function of temperature, is measured.
Detektor Thermal Conductivity
Created by Nick Buker 12/18/08
The ability of a colliding molecule to carry off heat depending on its thermal conductivity. Hydrogen and helium have high thermal conductivity and therefore will be more efficient at “cooling” a heated filament than other gases will
Detektor Thermal Conductivity
Created by Nick Buker 12/18/08
Detektor Thermal Conductivity
The TCD will respond to any substance different from the carrier gas as long as its concentration is sufficiently high enough.
Created by Nick Buker 12/18/08
Detektor Thermal Conductivity
Created by Nick Buker 12/18/08
Detektor Thermal Conductivity
Created by Nick Buker 12/18/08
Electron capture compound, X (highly electonegative element), tends to capture free electrons and increase the amount to ion recombination
X (F, Cl and Br) + e X-
Ion recombination : X- + N2+ = X + N2
The current will decrease and this decrease constitutes the signal.
Halogens, lead, phosphorous, nitro groups, silicone and polynuclear aromatics.
Insecticides, pesticides, vinyl chloride, and fluorocarbons
Detektor Electron Capture
Created by Nick Buker 12/18/08
Protein’s properties used in purification
Created by Nick Buker 12/18/08
Salting in and out
Created by Nick Buker 12/18/08
Solubility in ammonium sulfate