UV detection is the most widely used, but fails to see many compounds of interest. Other, so-called universal detectors have fallen short of the promise of combining application versatility with real performance.
What is HPLC Detection?
Now there is an alternative unlike any other - the Corona™ Charged Aerosol Detector. Based on a unique, innovative detection method, the Corona detector offers all-in-one performance benefits that refractive index (RI), low wavelength UV, evaporative light scattering (ELS) and chemiluminescence’s nitrogen (CLN) detectors simply can't match:
ChromaChem®- EVAPORATIVE LIGHT SCATTERING DETECTOR
Evaporative Light Scattering Detection with the ChromaChem Detector
- Universal detection of non-volatile compounds
- Sensitive detection of weak chromophores (e.g., lipids, phosholipids, triglygerides, carbohydrates, polymers and pharmaceuticals)
- More sensitive than RI and low wavelength UV detection
- Compatible with gradient elution HPLC
- Low temperature evaporation for semi-volatile and thermosensitive analytes
- Compatible with aqueous mobile phases, even at high flow rates
- Response factors are less variable than RI, UV and MS
- High baseline stability- insensitive to temperature and flow variations
Detection from Evaporative Light Scattering is based on the universal ability of particles to cause photon scattering when they traverse the path of a polychromatic beam of light. The liquid effluent from an HPLC is first nebulized and the resultant aerosol mist, containing the analyte particles, is directed through a light beam.
Presence or Absence of Chromophores, Fluorophores or Electroactive Groups
A signal is generated that is proportional to the mass present, and independent of the. Since essentially every compound can be separated by HPLC or micro-HPLC and detected by ELS, the ESA ChromaChem is the detector every chromatography laboratory should have.
The Chromachem Evaporative Light Scattering detector is a mass sensitive device, which provides a response directly proportional to an analyte’s mass in the sample. The presence of functional groups or chromophores are not necessary for detection. Relative amounts of compounds can be easily assessed by evaporative light scattering technology. Any non-volatile analyte can be detected and gradient elution can be employed to optimize the separation, aqueous as well as solvent based mobile phases can be used to detect compounds that are not generally "seen" by other detection techniques. This detector can be used in conjunction with mass spectrometers to provide a complete analysis of the sample.
The Chromachem's unique nebulization system and temperature controlled drift tube provides sensitivity, reliable and reproducible analysis. The unit's small footprint requires a minimum of bench space, allowing use in space limited conditions.
MODEL 526 / 528 VARIABLE WAVELENGTH UV/VIS DETECTORS
ESA’s Model 526 UV and Model 528 Variable Wavelength UV/VIS absorbance detectors are designed as modular HPLC detectors.
- Double-beam, variable wavelength capability
- Programmable wavelengths: 190 - 900 nm
- Easy-to-use Control Pad
- Available with a wide range of flow cells
- Automatic lamp startup/shutdown
- Pre-aligned lamps for easy changeover
- Remote autozero capability
- Optimized for use with ESA Coulometric electrochemical detection
The Model 526/528 detectors provide extremely low operating noise levels to 0.6 x 10-5 AU. This performance can meet severe analytical requirements for higher sensitivity. The improved stability also ensures reliable analyses not dependent on the ambient conditions. High response and low noise for ultra-high-speed analyses is ensured at a response of 0.1 sec. This provides sharpness of chromatographic peaks for allowing ultra-high-speed analyses with high sensitivity.
Automatic Wavelength Calibration for UV Range
The detector unit has a built-in mercury lamp for checking wavelength accuracy. Using its 254nm emission line, an ultraviolet wavelength frequently selected in liquid chromatography can be checked. A total of three wavelengths are checked at a time for enhancing reliability in wide-wavelength-range analyses.
Automatic lamp shutdown during inactive periods increases overall lamp life. Lamp usage is easily monitored through the front panel keypad and display. Simple programming is provided for wavelength scanning and range changes during an analytical run.
Optional flowcells are available for other many applications. Long-life replacement lamps and accessories are also available
ESA MODEL 530 HIGH SENSITIVITY FLUORESCENCE DETECTOR
ESA’s Model 530 Fluorescence detector is designed as modular HPLC detectors
Programmable Emission & Excitation Wavelengths
- Easy-to-use Control Pad
- Automatic lamp startup/shutdown
- Pre-aligned lamps for easy changeover Optional flowcells,
- Internal self-diagnostics
- Optimized for use with ESA Coulometric electrochemical detection
The Unique Three-Dimensional Optical Alignment Technologies
It is used in the Model 530 significantly reduces loss of light and provides high sensitivity in fluorescence measurement. Compounds that exhibit strong fluorescence are likely to be detected at concentrations nearly two orders of magnitude lower than UV-Vis absorbance. With this "bright" optical system, the Model 530 detector can provide a signal-to-noise ratio of over 600.
The detector can be operated as stand-alone module via the supplied control pad or through integration into the EZChrom™ Elite for ESA Chromatography Data System. Automatic wavelength calibration and documentation within EZChrom™ Elite for ESA software make it easy to comply with government regulations. And, control of external device functions is provided through programmable contacts.
The beam from the Xenon lamp converges on the excitation monochromator and disperses over a concave diffraction grating structured for minimal light loss. The programmed wavelength then passes through the variable exit slit. The sample in the flow cell is excited and the resulting fluorescence (emitted radiation) enters an emission monochromator. The selected emission wavelength strikes a measuring photomultiplier where the intensity of the excitation beam is measured as a function of time.
Automatic lamp shutdown during inactive periods increases overall lamp life. Lamp usage is easily monitored through the front panel keypad and display. Simple programming is provided for wavelength scanning and range changes during an analytical run. Long-life replacement lamps and accessories are also available.
