Lab Water Purification Adapted for Users

Wed, 03/06/2013 - 4:54pm
Tim Studt, Editorial Director

Pure lab water systems continue to evolve with new conveniences and capabilities, along with pre- and post-configurations.

Sartorius Stedim's Sartoguard NF prefilter introduces nanofleece materials to maintain high-quality liquid prefiltration while reducing overall filtration costs. Reliable, convenient, flexible, innovative and confidence are all words used by manufacturers of lab water purification products to describe their current systems. The specifications for the three types of lab water have not changed (and according to researchers, don't need to be changed). But manufacturers nonetheless continue to enhance their products to entice users with systems that are more reliable, easier to operate and boast increasing cost-effectiveness.

Sartorius Stedim Biotech GmbH, Gottingen, Germany, has a broad line of pure lab water products, including the arium pro Type 1 ultrapure water system, the arium advance pure water system and the arium comfort combination system. These product lines generate Type 1 to Type 3 ultrapure and pure lab water, delivering the desired water quality for any laboratory application. The arium comfort series, for example, is designed to deliver ASTM Type 1 ultrapure water, but it also produces Type 2 and Type 3 pure lab water in an efficient space-saving combination configuration. These systems feature innovative reverse osmosis (comfort I) and EDI technology (comfort II) with unique deionization cartridges to produce Type 1/2 water for critical and routine applications.

The arium pro is designed for the high-end user where reagent-grade water is required. It comes in four different models—a DI (deionization) version containing a cartridge set and sterile filter; a UV (ultraviolet) model that adds a 185/254 nm dual wavelength UV lamp to remove organic substances (TOC—total organic carbon); a UF (ultrafiltration) model containing an ultrafilter for removing endotoxins, pyrogens, DNA and RNA; and a VF model that combines the UV lamp and the ultrafilter in one device for producing water to particularly critical standards, including cell cultivation and chromatography applications.

Biopharm applications

Of course, once a particularly critical application has been resolved in the research lab, the resulting developed product has to be produced in a manufacturing environment to the same lab quality—as is the case with biopharmaceuticals. For this challenge, Sartorius researchers recently developed and introduced Sartoguard NF prefilters, featuring a combination of high-performance polyethersulfone (PES) membranes and innovative nanofleece technology. This is the first implementation of PES nanofleece material in liquid prefilters for biopharmaceutical manufacturing/research applications. The newly developed nanofleece technology provides an ultrafine fleece structure based on a nanofiber diameter of 120 to 150 nm compared with fiber diameters in conventional fleece materials of more than 500 nm. The resulting nanofleece structure offers enhanced clarification capabilities, even for extremely fine contaminates, along with high dirt-holding capacities, fast flow rates and high total throughput performance.

These filters are preferred for the expensive sterilizing-grade and Mycoplasma-retentive filters in challenging prefiltration situations for biopharmaceutical applications. All active filter materials—membranes and nanofleece—in the new prefilter series are made of PES, ensuring a minimum extractable footprint. 

Sartorius also recently introduced a new generation of ultrafiltration devices. The disposable Vivaspin Turbo 15 is optimally suited for protein, virus or nanoscale concentration, as well as desalting, dialysis and buffer exchanges. This device is available in a range of volumes from 4 to 15 mL and permits easy and complete recovery of the concentrate, yet is the fastest ultrafiltration device on the market.

Dispensing proficiency

Thermo Scientific's Barnstead GenPure xCAD provides ultrapure lab water with remote dispensing flexibility and control. Thermo Fisher Scientific, Waltham, Mass., offers a broad line of lab water purification and pretreatment products. The company recently introduced its new Barnstead GenPure xCAD water purification systems, which provide up to 200 L/day of Type 1 ultrapure (18.2 Mohm-cm) water from pre-treated feed water. All of the GenPure xCAD systems (short for Extended Control and Dispenser) include measuring cells for monitoring feed water conductivity to protect users' consumables, quick disconnects to easily change consumables, all core consumables and tubing, an RS232 port and full control of a remote dispenser and volumetric dispensing capabilities. The conductivity cells are calibrated prior to each measurement via a built-in reference resistance with 0.01/cm cell constraints. Temperature measurements are made with a platinum chip sensor with +/-0.1 C accuracy.

The GenPure system has an ultrapure water dispensing radius of 32", allowing the main system to be placed under the bench, freeing up valuable bench space. An ergonomic dispensing arm can be mounted on a wall or on the benchtop to provide precise volume dosing at the push of a button. Electronic dosing is also available for fully automatic volume control of 0.01 to 65 L with <0.5% accuracies. 

The GenPure systems also have optional real-time monitoring of TOCs for continual measurement of organic substances in the water. Continuous monitoring by the system of UV intensity also removes the risk of false TOC values due to diminished UV intensity. GenPure xCAD systems are available in UV, UF and combined UV/UF versions for the appropriate research applications. The UV and UV/UF models can be ordered with an optional TOC monitor for monitoring and removal. Both models with TOC monitors include UV intensity monitoring to ensure that the TOC readings are accurate.

For Type 2 applications, Thermo Fisher Scientific offers its Barnstead Pacific TII water purification systems and Barnstead Water Stills. The water stills are available in Mega-Pure Glass, Classic (copper, bronze and tin coating) and Cabinetized versions. Type 2 pure water is considered an essential part of creating consistently pure chemical reagents, microbiological buffers and media. It is also recommended as a pretreatment for Type 1 ultrapure water systems.

User flexibility

The article on pages 28 to 31 by researchers at EMD Millipore in Billerica, Mass., in this month's Laboratory Equipment provides insights into how differences in lab water quality can affect the experimental results of life science investigations. EMD Millipore offers a broad range of Type 1, 2, 3 and clinical lab water systems.

EMD Millipore's Milli-Q system can deliver ultrapure lab water to three independent point-of-delivery units. Its ultrapure Type 1 Milli-Q systems can operate directly from tap (potable) feed water systems or from Type 2 pure feed water (such as that from the Millipore Elix), from Type 3 reverse osmosis (Millipore RiOs), or from distilled or deionized feed water systems. For users who have access to a reliable pure water feed source, or those who need both large volumes of Type 2 pure water and small to large volumes of Type 1 ultrapure water, the Milli-Q Advantage A10 provides up to 300 L/day of Type 1 water for applications such as spectrophotometry, chromatography, cell culture and molecular biology. It also offers the convenience of providing up to three different Type 1 delivery points with water quality specifically tailored to the application. The company's Q-POD (Quality-Point-of-Delivery) unit—up to three Q-POD units are available in each A10—provides final polishing at the specific point of use.

Resistivity and TOC meters are also available in the A10 to provide control over both ionic and organic contaminants that can impact lab experimental results. The A10's resistivity meter includes features—such as a flow-through design, low cell constant and precise temperature measurements—that ensure the value displayed on the screen is meaningful. The A10's integrated TOC meter accurately monitors from 1 to 999 ppb and takes into account USP and EP suitability requirements.

Water polishing

Labconco's WaterPro PS Polishing Stations deliver Type 1, 18.2 Mohm-cm water from the dispensing valve or optional dispensing gun at a typical rate of 1.8 L/min depending on feed water flow rate and pressure and installed purification modules. The control panel on the device includes an LED display with a timed dispense feature that allows unattended dispensing of pure water for a set period of time from 1 to 99 min. The dispenser shuts off automatically once a user-set time has elapsed.

The WaterPro PS system has unpigmented virgin natural polypropylene bowls without any impurities to contaminate the process water, thereby maintaining low TOC levels. The bowls accommodate various combinations of deionization, carbon and organic adsorption filter cartridges based on the user's application requirements. Cartridges are large to minimize the number of filter changes required by the user. Specific systems for general chemistry, analytical instruments and the life sciences are offered in this system. Each model includes a built-in water quality alarm that flashes the actual water quality level in Mohm-cm to alert the user when the water quality falls below a set point.

Dispensers and sterilizers

Aqua Solutions, Jasper, Ga., offers Type 1 and Type 2 lab water systems that can operate on both ordinary tap (potable) water or pre-treated water to produce Type 1 water. The company recently introduced its Programmable Remote Dispenser 2700PRD, which provides easy and quick delivery of a measured volume of DI water. While designed for use on Aqua Solutions' water purification systems, it can be customized for operation on other systems as well. The dispenser has a volume range of 0.1 to 100 L in increments of 0.01 L. It accurately measures volumes over a flow range of 0.6 to 5 L/min.

Aquionics, Erlanger, Ky., also recently introduced a UV-C LED-based water disinfection system that can be integrated into ultrapure water systems, medical sterilization equipment and process water loops. The system uses UV LED lamps emitting light in the deep-UV range (UV-C) that destroy microorganisms on a cellular level. The LEDs can be tuned from 240 to 280 nm, allowing the targeting of specific pathogens. It can produce a UV dose of 60 mJ/cm2 at a flow of 1.9 L/min with only 50 mW of optical power required. The system is not affected by water temperature and can continue to operate with no flow. 





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