Frequently Asked Questions
What resistivity level do AMPAC USA high-purity water systems achieve, and which applications require it?
Our Type I systems produce water at 18.2 megohm-cm resistivity at 25 degrees C, which is the theoretical maximum for pure water. Semiconductor fabrication, HPLC mobile phase preparation, and cell culture media all require this grade to avoid ionic interference that would corrupt results. Analytical chemistry and molecular biology labs are the most common users at this specification.
What is the difference between Type I, Type II, and Type III laboratory water grades?
Type III water with resistivity above 1 megohm-cm suits general glassware rinsing and feed water for Type I polishers. Type II reaches 1-15 megohm-cm and covers most analytical instruments, autoclaves, and reagent preparation. Type I at 18.2 megohm-cm is reserved for critical analysis, molecular biology, and any application where trace ions or organics would introduce error.
How do your systems control TOC levels in high-purity water?
Our systems combine UV oxidation at 185 nm with mixed-bed deionization to drive TOC below 5 ppb, meeting ASTM D1193 Type I requirements. UV oxidation breaks organic compounds into carbon dioxide and water, which the DI polisher then removes. This dual-stage approach is more reliable than carbon alone for sustaining low TOC over time.
Are AMPAC USA high-purity water systems capable of producing pyrogen-free water for pharmaceutical applications?
Yes. Our pharmaceutical-grade systems incorporate ultrafiltration membranes with a molecular weight cutoff of 10,000 Daltons, which removes endotoxins and pyrogens to below 0.001 EU/mL. Combined with sanitizable piping and UV disinfection, these systems meet USP Purified Water and Water for Injection specifications when properly validated. Documentation packages support FDA and EMA submissions.
How often do DI resins and filters need replacement in a high-purity system?
Resin life depends heavily on feed water quality, but our systems include inline resistivity monitoring that gives real-time indication of resin exhaustion rather than relying on guesswork or fixed schedules. A facility with moderate-TDS municipal feed water typically replaces cartridge resins every 3-6 months, while systems fed by RO permeate can extend that to 12-18 months. Never rely on elapsed time alone when resistivity monitoring is available.