Dionex Corporation Home

Dionex IonPac AS18-4µm Hydroxide-Selective Anion-Exchange Column

Fast, High-Resolution Determination of Inorganic Anions and Low-Molecular-Weight Organic Acids

Attain the optimal combination of chromatographic speed and resolution using the new Thermo Scientific Dionex IonPac AS18-4µm anion-exchange column. This high-capacity, high-efficiency column provides excellent resolution of inorganic anions in diverse sample matrices. Compared to the previous Dionex IonPac AS18-Fast column, the new ion-exchange column uses smaller resin particles for more efficient separations resulting in faster run times, more accurate peak integration and more reliable results.The Dionex IonPac AS18-4µm anion-exchange column is the hydroxide-selective column of choice for compliance monitoring of inorganic anions in drinking water and wastewater samples in accordance with US EPA Methods 300.0 (A) and 300.1. 

The new Dionex IonPac AS18-4µm column offers the same selectivity as the Dionex IonPac AS18-Fast column, but with the reduced particle size, this column can separate the common inorganic anions in significantly less time without loss of resolution. Applications run on the Dionex IonPac AS18-Fast column can be easily transferred to the Dionex IonPac AS18-4µm column with the benefit of reduced run time with no loss in resolution. The Dionex IonPac AS18-4µm column is available in capillary format (0.4 × 150 mm), microbore format (2 × 150 mm) and standard bore format (4 × 150 mm). The capillary format offers the advantage of reduced eluent consumption, thereby lowering operating costs.  

  • Decrease run times, increase sample throughput without loss of resolution
  • Super fast isocratic separation of the common inorganic anions (less than 3 min) 
  • Recommended hydroxide-selective column for inorganic anions in diverse sample matrices
  • Inorganic anion and low-molecular weight organic acids in complex sample matrices
  • Meets performance requirements specified in US EPA Method 300.0 (A)

The smaller resin particles used in the Dionex IonPac AS18-4µm column produce increased back pressure. When operating the Dionex IonPac AS18-4µm capillary column at the standard flow rate of 0.010 mL/min, an IC system capable of operating up to 3000 psi is sufficient. However, to take advantage of the fast runs, using elevated flow rates, a high pressure capillary IC system, such as the Thermo Scientific Dionex ICS-5000+ HPIC or the Thermo Scientific Dionex ICS-4000 HPIC is required. The Dionex ICS-5000+ HPIC systems is required for standard operation of the Dionex IonPac AS18-4µm microbore and standard bore columns.