3 • Operation and Maintenance
Doc. 031644-02 9/03
3-23
Example Chromatogram: Selecting the Sample Wavelength,
Reference Wavelength, and Reference Bandwidth
Figure 3-6 shows the spectrum of caffeine. The operating conditions are:
Sample wavelength = 272 nm
Sample bandwidth = 5 nm
Reference wavelength = 325 nm
Reference bandwidth = 51 nm
These settings calculate the absorbance by the following equation:
Figure 3-6. Caffeine Spectrum
AU = log
avg
I
K
300 to 350
(
)
[
]
avg
I
K
210 to 274
(
)
[
]
--------------------------------------------------- offset (at autozero)
–