Elemental & Composition

TOC

Total Organic Carbon

TOC measures the total amount of carbon bound in organic compounds in water and aqueous samples. It is a fast, non-specific indicator of organic contamination in water, effluents and cleaning-validation rinses.

1 test optionWater, effluent & rinse samplesFrom sub-mg/L carbon levelsTypical turnaround 3–5 working days
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TOC measurement principleIllustrative
SampleCarrier gasFurnace, ~680 °CDehumidifierNDIR cellCO₂ peak
Organic carbon, burned and countedIllustrative
01 / Overview

What is TOC?

A TOC analyser oxidises the organic carbon in a sample to CO₂, either by catalytic combustion at around 680 °C or by UV–persulfate oxidation. A non-dispersive infrared (NDIR) detector measures the CO₂; inorganic carbon is purged off first or measured and subtracted.

TOC gives one number for all organic matter, with no need to know which compounds are present. It is quicker and more reproducible than COD or BOD, but it does not identify individual organics; chromatography is needed for that.

02 / How it works

How it works

  1. 01

    Inorganic carbon removed

    For NPOC, the sample is acidified and sparged to drive off carbonate as CO₂.

  2. 02

    Sample is oxidised

    An aliquot is injected into a hot catalytic furnace, turning organic carbon into CO₂.

  3. 03

    CO₂ is detected

    Carrier gas sweeps the CO₂ through an NDIR cell that measures its infrared absorption.

  4. 04

    Peak gives carbon

    The CO₂ peak area is compared with standards to give TOC in mg/L carbon.

03 / What it measures

What it measures

Total organic carbon (TOC)

Organic carbon content, reported as mg/L C.

Useful forDrinking, process and purified water

NPOC

Non-purgeable organic carbon, measured after acid sparging.

Useful forWaters rich in carbonate

Total & inorganic carbon

TC and IC measured separately, with TOC by difference.

Useful forEffluents, groundwater, process streams

Cleaning validation

Residual organics in rinse water and swab extracts.

Useful forPharma equipment cleaning

Water purity monitoring

Organic load in purified and high-purity water.

Useful forPurified water, WFI, ultrapure systems
04 / Test options

Choose the TOC options you need

1 option · none added yet

TOC test options
05 / Sample requirements

Sample requirements

Accepted forms
Water, effluents, aqueous extracts, rinse and swab samples
Quantity
40–100 mL of liquid per sample
Container
Clean glass vials or bottles with PTFE-lined caps
Storage
Keep cool (around 4 °C) and send promptly; acidify only if advised
Solids
Soils and other solids only after discussing with us first
  • Fill bottles to the top with no air bubbles
  • Keep samples chilled during transit
  • Mention the expected TOC level and any high salt content
  • No plastic bottles or caps that can leach carbon
  • No oils or heavy suspended solids without discussing first

Hazardous or air-sensitive samples: mention it in your request, and attach the MSDS if you have one.

06 / Results & turnaround

Results & turnaround

What you receive

  • TOC (or NPOC) in mg/L carbon
  • TC and IC values, where measured
  • Replicate injections and mean
  • Calibration and check-standard details
  • Report PDF

Turnaround & pricing

Typically 3–5 working days after samples reach the lab.

Price confirmed in your quotation, depending on user type, options and number of samples.

Sample report · IllustrativeExample TOC2.35 mg/L CIllustrative — not measured sample data
07 / Limitations

When TOC isn't the right fit

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