AU169: Determination of Silicate and Inorganic Anions in High Purity Water Using Sequential Detection and AutoPrep

Instrument Type: IC

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.

AU113: Determination of Dissolved Silica and Common Anions Using Dual Detection

Instrument Type: IC

Dissolved silica can be measured in solution as silicate using ion chromatography. While it cannot be determined by suppressed conductivity detection, silicate can be derivatized post-column with sodium molybdate reagent to form a complex that can be detected with high sensitivity at 410 nm. In this application, silicate and seven common anions, are separated using the IonPac AS22 column. After separation and detection by suppressed conductivity, the output from the suppressor is derivatized with molybdate reagent to detect silicate using visible absorbance.

AN83: Size-Exclusion Chromatography of Polysaccharides with Pulsed Amperometric Detection (PAD).

Instrument Type: IC

Size-exclusion chromatography is used in carbohydrate research to determine molecular weight distributions of polysaccharides. Size-exclusion columns separate biological macromolecules by hydrodynamic size. Pulsed amperometric detection (PAD), provides sensitive and specific detection of carbohydrates. Here, fractionated pullulan standards were used to determine the separation range of linear carbohydrates.This application note shows how SEC can be coupled to PAD.

AN149: Determination of Chlorite, Bromate, Bromide, and Chlorate in Drinking Water by Ion Chromatography with an On-Line-Generated Postcolumn Reagent.

Instrument Type: IC

This application note describes an improved ion chromatography (IC) method to quantify oxyhalide DBP anions and bromide at low concentration levels in reagent water, bottled water, and finished drinking water using an approach that is technically equivalent to U.S. EPA Method 326.0. The oxyhalide anions chlorite, chlorate, bromide, and bromate are separated on a Thermo Scientific Dionex IonPac AS9-HC column and measured by using suppressed conductivity detection (as in EPA Method 300.1), followed by postcolumn reaction (PCR) to enhance detection of bromate.