Between planned maintenance visits

Keep carbon measurement trustworthy.

A practical cross-platform routine for cleaner sampling paths, earlier warning signs and more reliable carbon measurement.

TOCTotal organic carbon analyser housekeeping guide
At low concentration, contamination becomes the result.Controlled sampling, clean flow paths, suitable reagents and disciplined blank and suitability review protect TOC measurement between planned maintenance events.

Take the routine into the laboratory

Choose a practical monthly task sheet for a physical instrument folder or an electronically completed laboratory record.

↓ Print-friendly PDF2-page A4 landscape · Rev 02
Low-ink version for printing
↓ Electronic record PDF2-page A4 landscape · Rev 02
Full-colour · complete and save electronically
Annual servicing is one important control—not a year-round maintenance strategy.
TOC analysers are exposed to sample residues, carbon contamination, reagent change, fluid- or gas-path wear and oxidation-system demand throughout the year. Their condition needs maintaining between service visits through clean handling, status review, performance checks and timely response to rising background or poor recovery.
ISOISO 8245:1999 ↗
Laboratory action

The laboratory’s role

Select the frequency that applies today and complete the checks shown.

⚠

Pause and investigate when you see:

Small changes can become preventable failures when they are allowed to persist.

•
Rising or unstable blankBackground carbon increases, varies or fails to return to its established condition without a sample-related explanation.
•
Poor recovery or suitabilityA standard, check solution or method-required suitability result falls outside its approved limit.
•
CarryoverA high sample influences a following blank, standard or low-level sample beyond the approved criterion.
•
Poor precision or responseReplicates, peak area, conductivity or calculated carbon response become erratic or drift from the established pattern.
•
Flow, pressure or gas warningBubbles, leakage, restriction, abnormal gas use or a fluid- or gas-path warning appears.
•
Abnormal reagent or consumable behaviourReagent use, catalyst condition, lamp status, membrane response or another technology-specific indicator changes unexpectedly.
One care standard · three OEM perspectives

Apply the routine to your instrument

Start with the cross-platform routine, then use the emphasis relevant to your installed system.

Exact commands, parts, intervals and acceptance criteria remain model- and method-specific.

Evidence and source library

Compendial, water-quality and OEM material supporting this cross-platform practical guide.

Primary sources
USP <643> · Total Organic CarbonCompendial framework for TOC as an indirect measure of organic molecules in pharmaceutical waters. Apply the current controlled chapter; no open-access substitute is presented as the chapter itself.
Controlled chapter
ISO 8245:1999 · Water quality — TOC and DOC guidancePublished ISO guidance for TOC and DOC in water, covering terms, interferences, reagents and sample pretreatment; it does not prescribe instrument-specific details.
View ISO record ↗
ISO 20236:2024 · High-temperature catalytic oxidative combustionMethod-specific water-quality standard for TOC, DOC, TNb and DNb by high-temperature catalytic oxidative combustion. Apply only to relevant methods and instruments.
View ISO record ↗
FDA / eCFR · 21 CFR §211.160Laboratory controls, specifications, sampling and testing under US pharmaceutical CGMP where applicable.
View regulation ↗

References are provided for transparency. USP <643> applies to compendial pharmaceutical-water TOC testing; ISO 8245 and ISO 20236 have their own scopes and are not interchangeable with every validated method. Current controlled editions, the validated method and approved acceptance criteria remain authoritative. Technology, gas, reagents, cleaning, consumables and shutdown procedures are model-specific.

Lab Optimise practical laboratory guides

A growing cross-platform collection for laboratory care between planned maintenance visits.

Lab waterPractical care between planned maintenance visits.Cold storagePractical care between planned maintenance visits.UV–VisPractical care between planned maintenance visits.
View all guides ↗Visit Lab Optimise ↗
Routine housekeeping protects condition and makes deterioration visible sooner.This guide supports—not replaces—governing requirements, validated methods, OEM instructions or qualified engineering intervention.