detect everything you inject with the pl-els 2100 evaporative light scattering detector
TRANSCRIPT
Detect Everything You Inject With the PL-ELS 2100
Evaporative Light Scattering Detector
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First Impressions
• Compact, modern design
• Flat top
• Small footprint, stackable
• Operation via control panel
and simple keypad
• Column connection at front
of detector
• One exhaust tube at rear,
one liquid waste port at front
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PL-ELS 2100 Front Panel Detail
200mm
450mm
200mm
Column Connection
Liquid Waste
Keypad415mm
Display
450mm
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Principle of Operation
The ELSD principle of operation employs three distinct stages :
• Nebulization
• Evaporation
• Detection
Eluent Inlet
Gas
Liquid WasteLight Source
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Nebulization
• Eluent flow mixed with N2/Air
• Concentric nebulizer gives efficient nebulization, stable droplet plume, uniform droplet size
• Narrower cone of spray plume allows a smaller nebulizer chamber, which minimizes band broadening
• Better recovery of semi-volatile solutes compared to cross-flow nebulizer
• Easier to align, reproducible from one detector to another
• Temperature independently controlled
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Evaporation
• Solvent removed by heating
•Temperature independently controlled
• PL-ELS 2100 has an additional gas input that aids evaporation (patent pending)
• Small volume evaporator
• Fast thermal equilibration
• Diffuser reduces turbulence inside evaporator tube which minimizes band broadening (patented)
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Detection
• Blue LED light source (480nm)• Intensity controllable by user
• Photomultiplier detector tuned to same wavelength for increased sensitivity
• Feedback control for light source provides constant output
• Detector mounted directly onto the optics which eliminates stray light loss and increases sensitivity
• Reduced volume in the optics chamber, minimizes band broadening
• Digital gain control to optimize full scale sensitivity
• Digital signal smoothing to optimize S/N ratio
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Advantages of Evaporative Light Scattering Detection
• Universal: responds to all compounds in the mobile phase.
- Detects compounds that do not possess a UV chromophore
e.g. polymers, sugars
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Advantages of Evaporative Light Scattering Detection: Pharmaceutical Mixture
Samples : 1. α-cyclodextrin 2. ß-cyclodextrin
3. Ibuprofen
Column: Aquasil C18 5µm, 150x4.6mm
Eluent A: Water
Eluent B: Acetonitrile
Gradient: 50-95% B in 5 mins
Flow Rate: 1.0 ml/min
Inj Vol: 20µl
Detector: PL-ELS 2100 (neb=30°C , evap=50°C, gas=1.0 L/min)
• Detects all components in a single run
ELSD
UV @ 220nm
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Advantages of Evaporative Light Scattering Detection
• Universal: responds to all compounds in the mobile phase
- Detects compounds that do not possess a UV chromophore
e.g. polymers, sugars
• Not dependent on spectroscopic properties of compound:
- Produces more uniform detection sensitivity for analytes
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Column: PLRP-S 100Å 5µm, 150 x4.6mmEluent A: 50% 0.1% TFA in Water : 50% 0.1% TFA in ACNFlow Rate: 1.0ml/minInj Vol: 10µlDetector: PL-ELS 2100 (neb=30°C, evap=30°C, gas=1.4 L/min) UV-VIS @ 280nm
Comparison of UV and ELS traces show that ELSD allows for a more uniform response than UV detection
Advantages of Evaporative Light Scattering Detection: Uniformity of Response
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Advantages of Evaporative Light Scattering Detection
• Universal: responds to all compounds in the mobile phase
-Detects compounds that do not possess a UV chromophore e.g. polymers, sugars
• Not dependent on spectroscopic properties of analyte:
- Produces more uniform detection sensitivity for analytes
• Not susceptible to baseline drift during gradient elution, temperature or solvent pump fluctuations
• ELSD compatible with a much wider range of solvents compared to RI and UV
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Fast Gradient, Fast Flow Rate Capability
Sample: Indapamide (IND), Dibutyl phthalate (DBP)
Column: PLRP-S 100Å 5µm, 50x4.6mmEluent A: 0.05% TFA in WaterEluent B: 0.05% TFA in ACNGradient: 5-95% B in 1 minFlow Rate: Increased from 2ml/min up to 5ml/minDetector: PL-ELS 2100 (neb=30°C, evap=30°C,
gas=1.6 L/min)
Note : IND is non-volatile, DBP is relatively volatile
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Fast Gradient, Fast Flow Rate Capability
gds 17feb03-0048.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0049.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0050.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0051.cgrm (ELS 2100 #0005 onchannel 4)
Res
pons
e
Minutes
2.0
111.6
221.2
330.8
440.4
550.0
0 1 2 3
2ml/min
3ml/min
4ml/min
5ml/min
IND
DBP
min
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Fast Gradient, Fast Flow Rate Capability
gds 17feb03-0048.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0049.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0050.cgrm (ELS 2100 #0005 onchannel 4)
gds 17feb03-0051.cgrm (ELS 2100 #0005 onchannel 4)
Response
Minutes
4.0
5.8
7.6
9.4
11.2
13.0
0.0 0.6 1.2 1.8 2.4 3.0
2ml/min
3ml/min
4ml/min
5ml/min
• Stable baseline throughout the gradient
• PL-ELS 2100 can operate in 100% up to 5ml/min
min
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Advantages of Evaporative Light Scattering Detection: Ideal Complement to LC-MS
•Similar operating principles to LC-MS - Volatile buffers
- Favors lower flow rates (i.e. 0.2-0.5 ml/min)
•Can develop LC methods on PL-ELS 2100 then transfer to LC-MS
•ELSD can provide supporting information when used in tandem with LC-MS
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Ideal Complement to LC-MS
Sample Mixture of known 1:1 ratio
LC-MS results show ratio to be3:1
UV-Vis result show ratio to be10:1
PL-ELS 2100 results show ratio to be1:1
(Response independent of optical properties)
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PL-ELS 2100 Sensitivity - Limit of Detection
Column: C18 5µm,150x4.6mmEluent A: 99% Water + 0.1 % TFAEluent B: 1% ACN + 0.1% TFAFlow Rate: 0.5ml/minDetector: PL-ELS 2100 (neb=50°C, evap=70°C, gas=1.2 L/min)Sample: DL-Glutamic Acid
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PL-ELS 2100 Sensitivity - Limit of Detection
• LOD improved with lower eluent flow rates and smaller ID column
4.6 ID S/N = 4.4
Caffeine Loading 30ng
2.1 ID S/N = 11.5
Caffeine Loading 100ng
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Operating the PL-ELS 2100: Onboard Instrument Control
Keypad
Interactive menu bar
Current methodMode
Detector output
Status
Actual values of set parameters
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Simple Operation
Two modes of operation :STANDBY
• Power on• LED off• Heaters off • Gas at minimum flow rate (1.2 L/min)
- Gas shuts off after 15 minutes
RUN• Power on• LED on
• Temperatures and gas flow controlled to set values
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• Digital Signal functions are accessed via the down arrow key in main menu screen
• Parameter Screen allows you to change - PMT output or gain (1-250) - Smoothing (1-50) - LED intensity (0-100)
Digital Signal Processing
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PL-ELS 2100 Control Software
Select mode of operation
Control parameters
Evaporator & Nebulizer temp
Gas flow (0-3.25 L/min)
Monitor output
Gain setting (0.1-250)
Signal smoothing (0-5)
• Log instrument conditions over time
• Load / Edit methods
- 10 programmable methods
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PL-ELS 2100 Control Software
• To use the control software simply connect the PL-ELS 2100 to a PC via a serial connection (RS232) on selectable COM port
• Where no serial port is available, a USB serial connector can be used
• Supplied as standard with the PL-ELS 2100
• Select 1 of 10 different temperature programs according to analysis
• Also available as a Software Development Kit for third party system integration
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PL-ELS 2100 Method Manager Software
• Used when the instrument is to be controlled via the onboard instrument control (rather than software control)
• This is a simple software utility designed to set up, edit and log defined methods which can then be downloaded to the
PL-ELS 2100
• Method Manager Software supplied as standard with the
PL-ELS 2100
• To use this software utility, simply connect the PL-ELS 2100 to a PC via a serial connection (RS232)
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PL-ELS 2100 Method Manager
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PL-ELS 2100: Routine Operation
• When running with the “XXX” method, the User has complete flexibility to change parameters via the PL-ELS 2100 keypad and display (e.g. for method development)
• Once standard methods for operation of the PL-ELS 2100 have been established, these can be stored using the PL-ELS 2100 Method Manager software utility and downloaded to the unit
• These downloaded parameters are stored as numbered methods (1-10) and cannot be edited through the keypad, only by running the PL-ELS 2100 Method Manager software
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A New Approach to ELS Detection
• Operating conditions of the PL-ELS 1000 is based on the properties of the eluent (e.g. high boiling point solvents require high evaporator temperatures)
• However, the PL-ELS 2100 operating conditions are determined by the properties of the analyte (e.g. semi-volatile or non-volatile)
•The PL-ELS 2100 can evaporate water at ambient temperature, unlike the PL-ELS 1000.
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Manipulating the PL-ELS 2100 Parameters
FOR NON-VOLATILE SOLUTES
• Nebulizer and evaporator can run hot to increase signal to noise ratio
• Gas flow is set as low as possible to maximize signal
FOR RELATIVELY VOLATILE SOLUTES
• Nebulizer and evaporator run cold to increase signal
• Gas flow is increased to control baseline noise
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Samples: 1. Acetanilide, 2. Indapamide, 3. Ibuprofen,
4. Dibutylphthalate
Column: C18 5µm, 150x4.6mm
Eluent A: 0.1% TFA in Water
Eluent B: 0.1% TFA in ACN
Gradient: 60-90%B in 5 mins
Flow Rate: 1.0mL/min
Detector: PL-ELS 2100 (neb and evap set at the same temperature, gas 1.8 L/min)
Note: peak 2 is non-volatile, peaks 1, 3, 4 are relatively volatile
Volatile Applications: Effect of Changing Evaporator Temperature
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Volatile Applications: Effect of Changing Evaporator Temperature
• At high temperature peak 2 has better S/N but peaks 1,3,4 are not detected
• At 30°C all four peaks are detected
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Environmental Application:Herbicides
Sample: Mixture of 10 Phenylurea herbicides
Column: C18 5µm, 250x4.6mm
Eluent A: Water
Eluent B: Acetonitrile
Gradient: 10-80%B in 40 mins
Flow Rate: 0.7ml/min
Inj Vol: 20µl
Detector: PL-ELS 2100 (neb=25°C, evap & gas flow varied)
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Environmental Application: Herbicides
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Non-Volatile Applications: PEG 400 Separation
Sample: PEG 400
Column: PLRP-S 100Å 5µm, 150x4.6mm
Eluent A: Water
Eluent B: ACN
Gradient: 10-30% B in 12 mins
Flow Rate: 1.0mL/min
Inj Vol: 10µl
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PEG 400: Effect of Changing Temperature
Evap 30°C Neb 30°C Gas 1.6 L/min
Evap 90°C Neb 90°C Gas 1.6 L/min
Higher temperatures increase S/N, no risk of loss due to evaporation
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PEG 400: Effect of Changing Gas Flow
Evap 70°C Neb 50°C Gas 1.2 L/min
Evap 70°C Neb 50°C Gas 2.4 L/min
Sensitivity is improved as gas flow is reduced
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Sample: 2mg/ml Starflower Oil
Column: C18 5µm, 250x4.6mm
Eluent A: ACN
Eluent B: DCM
Gradient: 30-50% B in 40 mins; 50-90% in 2 mins,
hold for 3mins
Flow Rate: 1.0ml/min
Inj Vol: 20µl
Detector: PL-ELS 2100 (neb=40°C, evap=70°C, gas=1.4 L/min)
Non-Volatile Application: Triglycerides in Natural Oils
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Non-Volatile Application: Triglycerides in Natural Oils
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Sample: PEG 1000
Column: Berger SFC Diol Column 60Å 6µm, 250x4.6mm
Eluent: Carbon Dioxide with 5% Methanol
Flow Rate: 2ml/min,
Pressure: Carbon Dioxide was pressure programmed from 100bar to 250bar at 10bar/min.
Inj Vol: 10µl
Detector: PL-ELS 2100 (neb=40°C, evap=30°C, gas=0.9 L/min)
Supercritical Fluid Chromatography: PEG Separation
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Supercritical Fluid Chromatography PEG Separation
Reduced band broadening allows high resolution SFC separations to be performed
PEG 1000
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PL-ELS 2100:DMSO Transparency
Sample: Pharmaceutical Mixture in DMSO
Column: C8 5µm, 50x4.6mm
Eluent A: Water
Eluent B: Acetonitrile
Gradient: 5-100% B in 5 mins
Flow Rate: 1.0ml/min
Inj Vol: 20µl
Detector: PL-ELS 2100 (neb=25°C, evap & gas flow varied)
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PL-ELS 2100 DMSO Transparency:Ideal for High Throughput Screening
Loss of volatile species occurs as temperature is increased
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•The design of the PL-ELS 2100 makes it transparent to DMSO at 25-30°C
• Great potential in the High Throughput Combichem market
• Unique to the PL-ELS 2100 due to its use of evaporation gas
PL-ELS 2100: neb=25°C, evap=30°C
PL-ELS 2100: DMSO Transparency:Ideal for High Throughput Screening
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Benefits of Evaporative Light Scattering Detection
• Universal detector: independent of the optical properties of the solute
• Compatible with gradient elution
• Ideal for fast gradient elution:- no solvent front. Removes the need for derivatization
• Compatible with chromatographic techniques such as MS and SFC
• Wide application area
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Additional Benefits of the PL-ELS 2100
• Operation in 100% water at 25°C
• DMSO transparency at ambient temperature
• Extremely low dispersion for high resolution separations (e.g. SFC)
• High sensitivity to volatile compounds
• Compatible with eluent flow rates, up to 5ml/min
• Rapid thermal equilibration
• Easy to use
• Extremely small footprint, stackable
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