Analytical and biological laboratory workflows require water with strictly controlled purity levels. Raw municipal tap water contains dissolved inorganic salts, organic carbon, dissolved gases, colloids, and microorganisms that interfere with reagent stability, analytical baselines, and enzymatic reactions. A laboratory water still provides thermal distillation to reliably eliminate these impurities.
Laboratory Water Purity Grades
Laboratory standards (such as ASTM D1193 and ISO 3696) categorize purified water into three primary grades based on resistivity, conductivity, and contaminant levels:
- Type I (Ultrapure Water, 18.2 MΩ·cm): Required for critical analytical applications including HPLC, ICP-MS, cell culture media preparation, and molecular biology (PCR, sequencing).
- Type II (Analytical Grade Water, 1–15 MΩ·cm): Suitable for standard clinical chemistry, microbiological culture media, buffer preparation, and feed water for Type I polishing systems.
- Type III (Primary Grade / RO Water, >0.05 MΩ·cm): Used for glassware washing, heating baths, autoclave reservoirs, and general rinsing.
How a Laboratory Water Still Operates
Thermal distillation works by boiling feed water into steam, separating volatile water vapor from non-volatile dissolved solids, heavy metals, and particulate matter. The steam travels into a condenser where cooling fluid brings it back to liquid distillate:
- Heating and Vaporization: Heating elements boil water in an evaporator boiler chamber. Non-volatile salts and minerals remain in the liquid phase as boiler residue.
- Steam Separation: Water vapor rises through a baffled column designed to prevent unvaporized water droplets from carrying contaminants into the condensing stream.
- Condensation: High-efficiency borosilicate glass or stainless steel condenser coils condense steam into high-purity distillate.
- Collection and Storage: Distillate drains into inert reservoirs protected against ambient airborne CO2 and particulate reabsorption.
Maintenance and Descaling
Mineral scale (calcium and magnesium carbonate) naturally accumulates on boiler walls and heating elements over time, reducing thermal efficiency and potentially damaging elements. Regular chemical descaling using mild food-grade acid solutions, coupled with low-water protection sensors, ensures sustained distillation output and water quality compliance.
View our water purification and distillation equipment on the IBS Catalogue.
