Transcript HPLC Detectors

HPLC Bulk Property Detectors
Refractive Index Detector
HPLC Bulk Property Detectors
Refractive Index Detector
Plus:
1) Measures a bulk property
2) Nearly Universal (different RI than mobile phase)
3) Comparable response for different analytes
4) Detects species with no chromophores
Minus:
1) Temperature dependent
2) Poor sensitivity (LOD ≈ 100 ng)
3) No gradient elution
HPLC Bulk Property Detectors
Evaporative Light Scattering Detector
Solid state laser
HPLC Bulk Property Detectors
Evaporative Light Scattering Detector
Plus:
1) Measures a bulk property
2) Nearly Universal (must be non-volatile)
3) Does not detect liquids (gradients are ok)
4) Detects species with no chromophores
Minus:
1) Signal not linear with concentration
2) Fair sensitivity (LOD ≈ 1 ng)
3) No salts or buffers in mobile phase
HPLC Bulk Property Detectors
Conductivity Detector
HPLC Bulk Property Detectors
Conductivity Detector
Plus:
1) Measures a bulk property
2) Nearly Universal (must be ionic)
3) Common for Ion Exchange LC
4) Detects species with no chromophores
5) Simple, robust
Minus:
1) Fair sensitivity (LOD ≈ 1 ng)
2) No salts or buffers in mobile phase
3) Gradients a challenge
HPLC Specific Property Detectors
Conventional UV-Vis Absorption Detector
Photodiode 1
Photodiode 2
Hg Pen
Lamp
254 nm
HPLC Specific Property Detectors
Multi-wavelength UV-Vis Absorption Detector
Deuterium
Lamp
Photodiode
Array
HPLC Specific Property Detectors
Multi-wavelength UV-Vis Absorption Detector
HPLC Specific Property Detectors
Multi-wavelength UV-Vis Absorption Detector
Plus:
1) Measures a specific property
2) Nearly Universal (must have chromophore)
3) Most common of all detectors (~75%)
4) Potential to provide qualitative info.
5) Simple, robust
Minus:
1) Fair sensitivity (LOD ≈ 1 ng)
2) Expensive with PDA, limited with Hg Lamp
3) Misses some important analytes
HPLC Specific Property Detectors
Fluorescence Detector
HPLC Specific Property Detectors
Fluorescence Detector
HPLC Specific Property Detectors
Fluorescence Detector
Plus:
1) Measures a specific property
2) Highly Selective (must fluoresce)
3) Second most common of all detectors (~15%)
4) High sensitivity (LOD ≈ 0.01 ng)
5) Can interrogate very small volumes
Minus:
1) Not Universal
2) Limited Applications
HPLC Specific Property Detectors
Electrochemical Detector
HPLC Specific Property Detectors
Electrochemical Detector
Plus:
1) Measures a specific property
2) Highly Selective (depends on reduction potential)
3) High sensitivity (LOD ≈ 0.01 ng)
Minus:
1) Not Universal
2) Must have electrolyte in mobile phase
3) Mobile phase must be aqueous
4) Gradients not possible
HPLC Element Specific Detectors
ICP Detector Detector
HPLC Element Specific Detectors
ICP Detector Detector
Plus:
1) Can be Highly Selective
2) Can be nearly Universal
3) Can have single sensitivity for all analytes
Minus:
1) $$$
2) Mobile phase must be aqueous
4) Mobile phase must not contain element of interest
UV-Vis detection of sugars in juice
UV-Vis detection of sugars in juice
ICP Carbon detection of sugars in juice
ICP Carbon
detection of sugars
in orange juice
ICP Carbon detection of amino acids
ICP Carbon detection of amino acids
HPLC Derivatization Detectors
Tag analytes with fluorophore
Before or After Separation
HPLC Derivatization Detectors
Tag analytes with fluorophore
Before or After Separation
HPLC Indirect Detectors
Detect the change in a constant signal
as the analyte passes
Recent HPLC Detector
Hollow Cathode Detector
Recent HPLC Detector
Hollow Cathode Detector
Recent HPLC Detector
Hollow Cathode Detector
Recent HPLC Detector
Hollow Cathode Detector
Recent HPLC Detector
Hollow Cathode Detector
Recent HPLC Detector
Hollow Cathode Detector