Technical poster by researchers at AstraZeneca has assessed the capabilities of the Corona Charged Aerosol Detector (Cad), and discovered that it offers numerous advantages over other HPLC detectors
Available from ESA Biosciences, a technical poster prepared by researchers at AstraZeneca's Alderley Park research centre in Macclesfield, UK, has assessed the capabilities of the company's unique Corona Charged Aerosol Detector (Cad), and discovered that it offers numerous advantages over other HPLC detectors commonly used in pharmaceutical research.
There are a large number of different instruments for identifying the compounds separated by an HPLC column, including ultra-violet (UV) detectors, diode array detectors and refractive index monitors, but they all have limitations in terms of the range of compounds that they can detect.
Even so-called universal HPLC detection methods, such as evaporative light scattering detection (ELSD) are known to exhibit problems.
The most serious of which for pharmaceutical researchers is that ELSD often generates very different responses for compounds of the same molecular weight.
This means that it cannot accurately detect the quantities of the separated compounds, which makes it unsuitable for tasks such as detecting the level of impurities in potential drug compounds.
The independent work by the AstraZeneca researchers clearly demonstrated that the ESA Corona Cad could accurately deduce the quantity of compounds separated by both isocratic and gradient HPLC.
Furthermore, they found that this measurement of quantity is less dependent of chemical structure and that different compounds of the same molecular weight generated similar responses.
This feature of CAD should make it ideal for studying protein-ligand binding, because it can precisely measure the quantities of both the protein and each individual ligand.
To test this supposition, the researchers investigated the binding of four different ligands to the protein IGF, and discovered that the levels of binding as revealed by the CAD closely matched binding data previously obtained by other means.
Charged Aerosol Detection is a robust HPLC detection technology that delivers advanced capabilities of interest to every HPLC user laboratory.
Corona Cad's revolutionary technology is applicable for measuring virtually any non- or semi-volatile compound such as drug compounds, carbohydrates, steroids, proteins, lipids, peptides and sugars.
With Charged Aerosol Detection, the HPLC column eluent is nebulised and the resulting droplets dry at ambient temperature producing analyte particles.
A second stream of gas is positively charged as it passes a high-voltage, platinum corona wire.
The charged gas collides with and transfers charges to the opposing stream of analyte particles.
A negatively charged, low-voltage ion trap removes high-mobility particles while analyte particles transfer their charges to a collector.
The charge transferred to the collector is in direct proportion to analyte mass.
ESA is a manufacturer and supplier of analytical instruments for the life science, clinical diagnostic, drug discovery and pharmaceutical industries.
Founded in 1968, ESA offers a complete line of HPLC systems, components, and advanced detectors, along with a broad range of analytical services.
