Checklist For Best Results - Agilent Technologies Cary 8454 Installation Manual

3 Good Measurement Practices
General Considerations
In an unstirred cell, it is sometimes possible to observe local photodegradation
of sensitive analytes. Because the actual volume of the sample in the light path
is very small, stirring the sample will reduce the time any given analyte
molecule is in the light path. This minimizes the photodegradation and
increases homogeneity. Using a flow cell with continuous flow can yield
similar results.

Checklist for Best Results

Cell:
Measurements:
42
Cell is made of quartz or glass
Apertured cells have black sides
Apertured cells have an aperture greater than or equal to 3 mm
Cell windows are free of fingerprints and other contamination
Flow cell used instead of an apertured standard cell
Solution in cell is free of floating particles
Both solution in cell, and cell walls are free of bubbles
Solution in cell is mixed homogeneously
Blank measured on same solvent as sample
Blank measurement shows a flat baseline (Figure 10 and Figure 11 show a
good and a poor baseline)
Cell orientation of blank and sample measurements is the same
Ideally, the cell is not removed between the measurement, which means the
cell is filled/rinsed using a pipette or a flow cell is used
Time between blank and sample measurement should be short
Agilent Cary 8454 UV-Visible Spectroscopy System Installation Guide