Silicate is monitored in ultra high purity water because it is one of the first ions to break through deionization cartridges used for water purification. AN 170 showed how an ion chromatography system can determine sub-μg/L concentrations of silicate by visible absorbance after a post-column reaction. In these waters, low μg/L and sub-μg/L concentrations of inorganic anions and short chain organic acids are also determined. This Application Update (AU) shows how low concentrations of inorganic anions, organic acids, and silicate can be determined in one injection.

This note describes the use of the eluent generator with the high-volume direct-injection technique to determine trace anions in high-purity waters. The ability to generate high-purity and carbonate-free eluents on-line improves performance for trace-level analysis. Retention time reproducibility is improved, especially for early-eluting species. The baseline shift from the hydroxide gradient is significantly reduced. Two columns are described: the 2-mm IonPac AS11 & 2-mm AS15. Common inorganic anions and low molecular weight organic acids are determined below μg/L levels in less than 35 min.

This note describes the use of an eluent generator with the high-volume direct-injection technique to determine trace anions in high-purity waters. The ability to generate high-purity and carbonate-free eluents on-line improves performance for trace-level analysis. Retention time reproducibility is improved, especially for early-eluting species. The baseline shift from the hydroxide gradient is significantly reduced. Two columns are described: the 2-mm IonPac AS11 & 2-mm AS15. Common inorganic anions and low molecular weight organic acids are determined below μg/L levels in less than 35 min.

Converting IC methods from analytical to capillary scale provides user with advantages. For example, the system can be left on and ready to run samples, the capillary eluent generation cartridge (EGC) lasts much longer. This application demonstrates the measurement of trace levels of ionic impurities in water using capillary ion chromatography with the Dionex IonPac AS15 column. This is critical for the identification and prevention of corrosive conditions in many power plant components.

This document describes the use of the EG40 potassium hydroxide (KOH) eluent generator with the IonPac AS15-5µm column for trace anion analysis. The EG40 generates high-purity and carbonate-free hydroxide eluents on-line to improve the method performance for determination of target analytes at trace levels. The high-volume direct injection technique is used to achieve sensitive detection at sub-µg/L levels. The analytes are detected by suppressed conductivity with a 2-mm ASRS-ULTRA operated in the Gas Assisted Recycle mode. This Update expands on work presented in Dionex Technical Note 48.