An automated inline solution to remove interfering substances in your sample

Need to remove matrix interferences such as metals and cations, or hydrophobic organic substances and surfactants that interfere with your ion chromatography (IC) applications? Thermo Scientific Dionex Guardcap Vial Caps provide a smart, automated sample preparation and filtration solution for your IC analyses.

ICS-4000 Capillary HPIC System with AS-DV autosampler
ICS-4000 Capillary HPIC System with AS-DV autosampler

How Dionex Guardcap Vial Caps work

The Dionex Guardcap Vial Cap embeds resin that removes specific types of interfering substances from your matrix. The Guardcap Vial Cap is placed on top of 5mL Dionex PolyVials in the Dionex AS-DV autosampler. The Dionex AS-DV holds 50 vials that can be sampled in any order, and programmed to take multiple samples from each vial. The vial design eliminates the need for an external sampling pump. Important parameters that can affect the reproducibility of sample preparation such as timing, flow rate, and delivery volume are easily set and controlled by the autosampler.

Dionex Guardcap Vial Caps are embedded with resin and fit on Dionex PolyVials
Dionex Guardcap Vial Caps are embedded with resin and fit on Dionex PolyVials

Dionex Guardcap Vial Caps

There are three versions of Dionex Guardcap Vial Caps currently available:

Automatically remove alkaline earth and transition metals, neutralize high pH samples, and filter particulates. Dionex Guardcap H vial caps are embedded with Thermo Scientific Dionex OnGuard H resin.

Automatically remove alkaline earth and transition metals and filter particulates without changing the sample pH. Dionex Guardcap Na vial caps are embedded with Dionex OnGuard Na resin. Since sample pH remains unchanged, Dionex Guardcap Na vial caps are ideal for treating samples that contain pH-sensitive analytes (e.g., nitrite).

Automatically remove particulates and hydrophobic organic substances including non-ionic surfactants, hydrocarbons, aromatic dyes, and some carboxylic acids. Dionex Guardcap HRP vial caps are embedded with hydrophilic reversed phase resin.

Thermo Scientific Dionex Guardcap AEX vial caps are embedded with anion-exchange resin in borate form to automatically remove anions, neutralize acidic samples, and filter particulates.

Dionex Guardcap Chemistries and Example Applications

ProductFunctionalityCapacity (meq/cap)SolventspH StabilityExample Application
Dionex Guardcap H Vial CapsCation-exchange hydronium form500-20% HPLC solvents0-14Removal of alkaline earth and transition metals; pH adjustment of basic samples
Dionex Guardcap Na Vial CapsCation-exchange sodium form500-20% HPLC solvents0-14Removal of alkaline earth and transition metals
Dionex Guardcap HRP Vial CapsHydrophilic reversed phase20 mg benzoic acid at pH <40-20% HPLC solvents0-14Removal of hydrophobic organics and surfactants
Dionex Guardcap AEX Vial CapsAnion-exchange borate form500-20% HPLC solvents0-14Removal of anions; pH adjustment of acidic samples
  Dionex Guardcap H Dionex Guardcap Na Dionex Guardcap HRP Dionex Guardcap AEX
Save time and effort vs. offline sample prep
Protect columns and suppressors
Remove particulates
Remove transition metals    
Remove alkaline earth metals    
Remove anions      
Neutralize basic samples      
Leave sample pH unchanged    
Neutralize acidic samples      
Remove some surfactants      
Remove hydrocarbons      
Remove aromatic dyes      
Remove hydrophobic substances      
Remove some carboxylic acids