Laboratory water purification: how can consistently suitable water quality be obtained for analyses?

Water is often the lab’s first “reagent”. To avoid baseline noise, ghost peaks and temperamental cultures, a water purification system delivers Type I/II/III water compliant with ASTM and ISO 3696. From RO (reverse osmosis) to EDI, from ion-exchange cartridges to UV 185/254 nm and ultrafiltration, our solutions — instruments, consumables, distillers and complete packs — make your workflows reproducible and robust. Continuous resistivity and TOC monitoring, volumetric dispensing and eco modes complete the experience.

What types of laboratory water purification systems are there, and how do you choose the right one?

Water purification systems combine pretreatment (sediment, activated carbon), reverse osmosis to reduce salts and organics, then DI or EDI to achieve Type II/III water. Polishing modules with ion exchange cartridges, UV and ultrafiltration (5–10 kDa cut-off) deliver Type I water up to 18.2 M?·cm with very low TOC; a 0.2 µm point-of-use filter secures distribution.

The distiller separates by evaporation–condensation. Robust and straightforward, it provides consistent water for general preparations or as feed water, but it is energy-intensive and less effective for volatiles; it does not replace a Type I polisher for HPLC/LC-MS.

Consumables (mixed-bed cartridges, RO membranes, prefilters, UV lamps, ultrafilters) determine performance. References with RFID tracking and quick-connects reduce errors and simplify traceability. Complete bundles combine the unit, a reservoir with UV recirculation, and local or remote dispensing for plug-and-play integration.

Selection criteria: required grade (ASTM/ISO), flow rate and daily volume, TOC, reduction of endotoxins for cell culture, trace metals for ICP-MS, ergonomics (display, volumetric dispensing), and environmental impact (RO reject ratio, EDI without chemical regeneration, standby modes).

Type	Principle	Applications
RO + DI/EDI (Type II/III)	RO membrane followed by deionisation	Preparations, feeding polishers, washing
Type I polisher	Ion exchange, UV, UF, 0.2 µm filter	HPLC/LC-MS, PCR, ICP-MS, cell culture
Distiller	Evaporation–condensation	Raw materials, general analysis, feed water

In which fields are water purification systems used?

Life sciences: Type I water for PCR/RT-qPCR, cell culture, preparation of RNase-free buffers with reduced endotoxins and DNase/RNase.

Pharma and quality control: dissolution testing, HPLC/UPLC with low TOC, ASTM compliance, traceability and batch tracking.

Environment and chemistry: ICP-OES/MS, AAS, preparation of trace-metal standards and analytical blanks.

Agri-food/cosmetics: microbiology, formulation, final rinse of glassware.

Lab support: feeding autoclaves and laboratory washers, distribution loops, critical rinsing.

Education/R&D: flexibility from Type III to Type I depending on the project.

Available laboratory water purification systems and consumables

Frequently asked questions about laboratory water purification

What’s the difference between Type I, II and III waters?
Type I (ultrapure) is for sensitive analyses; Type II for preparations; Type III for washing and feed water. Choose according to application and standards.

Is a still enough for chromatography?
No. Distillation is useful and robust, but for HPLC/LC-MS you need a Type I polisher (RO + DI/UV/UF) delivering low TOC and 18.2 M?·cm.

When should I replace the consumables?
At the first drop in resistivity, rise in TOC or by time/volume. In practice, every 6–12 months depending on feedwater quality, organic load and usage.

How do I limit endotoxins and RNase?
Use a dedicated UF module and a UV 185/254 nm lamp, purge regularly, work cleanly and replace 0.2 µm point-of-use filters.

Which water for ICP-MS and trace analysis?
Prefer Type I with ultra-low metals and TOC, inert materials and rigorous rinsing to avoid any recontamination at the point of use.

Does reverse osmosis waste water?
Modern systems optimise reject, allow internal reuse and EDI avoids chemical regenerations. Set the recovery rate according to feed quality.

What installation precautions?
Check inlet pressure and quality, provide a tank with UV recirculation, minimise dead legs, plan sanitisation cycles and periodic TOC/resistivity checks.