Titration & electrochemistry
Total Organic Carbon (TOC) Analyser
Oxidises organic compounds in water to carbon dioxide and measures the CO₂ formed to give the total organic carbon content. The standard test for organic contamination in purified water and water for injections.
- Pharmaceutical
- Biotech
- Semiconductors
- Power generation
- Environmental
- Drinking water
TROUBLESHOOTING
Common problems, causes and fixes
High blank values
Likely causes
- • Contaminated reagent water
- • Dirty vials or caps
- • Contaminated reagent
- • Carry-over from a high sample
What to do
- • Use fresh TOC-free reagent water
- • Use certified low-TOC vials
- • Replace reagents
- • Run extra rinses or blanks after high samples
Response efficiency outside 85–115%
Likely causes
- • UV lamp or catalyst losing performance
- • Wrong standard concentration
- • Oxidiser exhausted
What to do
- • Replace the lamp or catalyst
- • Prepare fresh standards and check calculations
- • Replace the oxidiser reagent
Poor repeatability
Likely causes
- • Air bubbles in the sample line
- • Contamination during sampling
- • Detector or membrane problem
What to do
- • Purge lines and check fittings
- • Review sampling technique and gloves
- • Inspect and replace the membrane or call service
Sudden rise in online TOC
Likely causes
- • Real contamination of the water system
- • Sanitisation residues
- • Sensor fault
What to do
- • Take a grab sample and test offline
- • Check recent maintenance or sanitisation activities
- • Verify the sensor with a standard
Results higher than expected after calibration
Likely causes
- • Calibration standards prepared in water with high TOC
- • Blank not subtracted correctly
What to do
- • Prepare standards in fresh reagent water and repeat
- • Review the blank correction settings
In LimsPulse · Calibration Management
Keep every TOC analyser in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.