Spectroscopy
Fluorescence Spectrophotometer (Spectrofluorometer)
Shines light of one wavelength on a sample and measures the longer-wavelength light the molecules give back (fluorescence). Very sensitive and selective for fluorescent compounds.
- Pharmaceutical
- Biotech
- Clinical
- Environmental
- Food & beverage
- Research
TROUBLESHOOTING
Common problems, causes and fixes
Weak or no signal
Likely causes
- • Lamp failed or near end of life
- • Wrong wavelengths or slits
- • Shutter closed
- • PMT voltage too low
What to do
- • Check lamp and replace
- • Check method settings
- • Check shutter status
- • Increase PMT voltage within the linear range
Signal saturating
Likely causes
- • Concentration too high
- • PMT voltage too high
- • Slits too wide
What to do
- • Dilute the sample
- • Lower PMT voltage
- • Narrow the slits
Calibration curve bends at high concentration
Likely causes
- • Inner-filter effect
- • Self-quenching
What to do
- • Work at lower concentrations
- • Keep absorbance at λex low
Unexpected peak in blank
Likely causes
- • Solvent Raman band
- • Fluorescent impurity in solvent or cuvette
- • Second-order scatter
What to do
- • Change λex to move the Raman band
- • Use fluorescence-grade solvent and clean cuvettes
- • Use an emission cut-off filter
Readings drift
Likely causes
- • Lamp not warmed up
- • Sample temperature changing
- • Photobleaching
What to do
- • Allow full warm-up
- • Use a thermostatted holder
- • Reduce slit width or exposure time
In LimsPulse · Calibration Management
Keep every Fluorimeter in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.