In-line Matrix Elimination of Cations for Improved Anion Analysis Using Ion Chromatography

Poster Presentation

Presented by W. Liu
Prepared by J. Guajardo, D. Jamieson, T. Wu, R. Slingsby, R. Jack
Thermo Fisher Scientific, 1206-1212 Oakmead Pkwy, Sunnyvale, CA, 94085, United States

Contact Information: [email protected]; 720-648-4759


In ion chromatography (IC), sample preparation is often focused on matrix elimination of interfering non-analyte species including species that interfere with separation and/or detection, or foul the system. One of the examples is to remove the high concentration of calcium and magnesium in hard water before anion analysis to increase the lifespan of column and suppressor. The workhorse technique is that of matrix elimination using offline cartridges such as OnGuard although some inline techniques are useful using multiple-use cartridges such as InGuard. We have recently developed sample vial caps performing as cation-binding resin filters. As the sample is flowed through these caps such as Guardcap H, Na or Hydrophilic Reversed Phase (HRP) using the AS-DV or AS40 autosampler, metals or surfactants in the matrix is easily eliminated from samples with or without changing the pH of the sample and neutralization of bases is also accomplished. In this paper we will report on two new Guardcap chemistries, Na and HRP, show the features of this concept and also key applications for these three chemistries.

In conclusion, the automated inline sample preparation/matrix elimination can improve the reproducibility of an analysis by tightly controlling processes including timing, flow rate, volumes delivered, mixing parameters. It may also offer lower costs compared to offline processes by reducing labor and support items such as disposable syringes, and by allowing the use of instrumentation during extended hours. Since each vial cap is used on one sample there is no concern about contamination or carryover from previous samples. The municipal and state utilities labs, as well as environmental contract labs will definitely find the product useful in their IC workflows.