|Polishing Up On Water Quality|
C. Devaux, C. Monferran, M. Tarun, E. Riche, D. Darbouret
Laboratory Equipment – Chromatography Techniques (2010) Dec. 2010
Water plays a critical role in many analytical methods—particularly in the preparation of samples, standards, blanks, and eluents. It is crucial that water used for these applications does not introduce any impurities that could interfere with analytical results. As modern analytical instruments become capable of detecting ever increasingly low concentrations of analytes, ensuring the lowest level of background interference has become even more important—and more difficult. To meet this challenge, laboratory water purification systems have evolved accordingly. Current systems such as the Milli-Q Integral use a sophisticated combination of purification technologies to reduce ions, organics and other potentially background-causing contaminants to extremely low levels (i.e., 18.2 MΩ.cm resistivity and <5 µg/mL of TOC).Full Text Article
The VOC-Pak® Polisher is designed to produce water with volatile organic compound (VOC) concentrations below the analytical limit of detection.
VOCs are industrial contaminants that may cause health and safety issues and therefore should be detected in the environment. They are routinely analyzed in water, soil, gas and air. Specifications for VOCs in drinking water have been established by different regulatory agencies in many countries.
VOC-Pak® is designed to be connected to the outlet of ultrapure water equipment, in particular, the Q-POD® dispenser of Milli-Q® systems. It contains a specific type of activated carbon chosen for the efficient removal of numerous VOCs. It is warranted to deliver at least 300 liters of VOC-free water suitable for glassware rinsing, production of standard solutions or dilutions, for instance, in Gas Chromatography analysis. Each VOC-Pak® Polisher is delivered with its Certificate of Quality.
The VOC-Pak® Polisher has been designed to remove the VOCs listed below, provided that their feed water concentration does not exceed 1 ppb* and the TOC is below 5 ppb. To warrant this, the following challenge tests were performed:
|VOC tested||Challenge (ppb) (*)||Quantification limit (ppb) (**)||Concentration after POD pak (ppb) (***)|
|(*) Challenge = VOC concentration in feed water upstream of VOC-Pak® Polisher
(**) Quantification limit: limit of quantification of the VOC measured by GC downstream of the VOC-Pak® Polisher
(***) Concentration of VOC below the VOC-Pak® Polisher for a feed water concentration of 1 ppb
Analysis of the VOCs in ultrapure water were performed according to internal procedure 84214SO, using a Purge & Trap GC-MS system (GC model 6890N and MS model 5975B, both from Agilent Technologies).
A copy of the complete qualification report with description of the analytical procedure is available upon request.