Quick Optimization Tips
Wavelength and Bandwidth
- A browser wavelength can be used to detect all peaks. For example use a wavelength of 250 nm with 100 nm bandwidth.
- For increased selectivity select a specific wavelength with a narrower bandwidth for sample and reference wavelengths.
- For samples with high concentrations use a peak or valley in the spectrum to give the optimum linearity.
- A reference wavelength should be in a range where analytes show little or no absorbance.
- A broad bandwidth should be used. Note: Ensure that the reference bandwidth does not obscure and analyte peaks which will affect quantitation.
- Use a narrow peak of interest from the chromatogram and set the peak width close to its width.
- Set the slit width to 4 nm for normal applications.
- Use a narrow slit (1 or 2 nm) for the identification of analytes with fine spectral structures or for high concentrations.
- To detect very low concentration analytes use a wide slit (e.g. 16 nm). The signal used should have a bandwidth at least as wide as the slit width.
Response Time/Data Collection Rate
- Set the response time to 1/3 of the peak width at half height of the narrowest peak of interest i.e. 0.02 min peak, 0.5 s response time.
- Each peak should ideally be defined by at least 20 data points. If peaks co-elute or when there is a low signal to noise ratio 40 data points per peak should be used.
- Lower data collection rates can be used for wide peaks, and conversely, with peaks of interest that are less than a few seconds wide faster data collection rates can be used.