Optional optical filters are available for the Alliance iS PDA detector to reduce photodegradation of UV-sensitive analytes by selectively blocking or transmitting specific UV wavelength ranges, enhancing analytical performance and sample integrity.
The Alliance iS PDA detector supports an optional optical filter module designed to minimize oxidation and hydrolysis of UV-sensitive analytes caused by light during analysis. These filters selectively attenuate or block specific UV wavelength ranges before the light reaches the sample, helping preserve sample integrity and improve analytical performance. The UV filters require an optional PDA flow cell that is specifically designed to be compatible with either a cuvette or the optional filters. For more information, see Replacing the PDA detector's flow cell and Installing the optional UV filters.
Caution: To avoid a Wavelength Verification Failure message, do not install the optional UV filter until after the PDA detector completes its startup sequence. The system verifies the PDA detector's calibration using two spectral peaks from the deuterium lamp and three absorbance peaks from its integrated erbium filter. Upon startup, the system verifies detector calibration by comparing the locations of these peaks with expected wavelengths based on calibration data stored in the detector's memory. If the results of this verification differ from the stored calibration by more than 1.0 nm, the detector displays a Wavelength Verification Failure message. If you install a UV filter before the system verifies the PDA detector's calibration, the verify calibration workflow fails. See
Calibrating the PDA detector and
Verifying the PDA detector's calibration for more information.
Available filter options:
- 214 nm long pass filter: The 214 nm long pass filter allows wavelengths from 214 nm to 800 nm to pass through the flow cell, effectively blocking shorter wavelengths that are more likely to cause photodegradation of sensitive analytes. It minimizes photodegradation by filtering out high-energy UV light below 214 nm while retaining full 3D spectral capability above the cutoff wavelength.
- 220 nm band pass filter: The 220 nm band pass filter allows wavelengths from 215 nm to 225 nm to pass through the flow cell and is optimized for peptide mapping and protein analysis, targeting peptide backbone absorbance.
- 260 nm band pass filter: The 260 nm band pass filter allows wavelengths from 255 nm to 265 nm to pass through the flow cell. It is suitable for nucleic acid analysis, aligning with DNA/RNA absorbance peaks.
- 280 nm band pass filter: The 280 nm band pass filter allows wavelengths from 275 nm to 285 nm to pass through the flow cell and is designed for protein and amino acid detection.
Benefits of using the optional UV filters include:
- Reduced UV-induced degradation
- Flexibility to tailor light exposure based on application needs
PDA detector features
