HPLC Application Note: Ultralow Detection Limits for Inorganic Anions and Cations in Power Station Boiler Water Analysis

Featured Article

HPLC Application Note: Ultralow Detection Limits for Inorganic Anions and Cations in Power Station Boiler Water Analysis

Most basic recommended instrument:

  • IonQuest Ion Chromatography System 2, including CE 4020 two-channel on-line degasser, CE 4601C column heater, and Power- Stream software.
  • CE 4715 continuous anion regenerant suppressor and 4720 01 01 column overpressure valve

Boilers used in power stations hold ultrapure water, and the purity of that water must be determined by highly sensitive techniques. Ion chromatography is a technique that offers high sensitivity. In this case study, Cecil Instruments demonstrates use of the IonQuest Ion Chromatography systems in the detection of ultralow ppb levels of common inorganic ions.

Typical method
Chloride, bromide, sulfate, and mitrate ions were detected under the following analytical conditions:

Analytical column: Allsep™ Anion column (Grace, Deerfield, IL), 7 μm, 150 × 4.6 mm

Mobile phase: Sodium carbonate/sodium bicarbonate buffer, pH 10.5

Mobile phase flow rate: 1.3 mL/min
Column temperature: 35 °C
Detector temperature: 35 °C
Injection volume: 100 μL of untreated sample
Offset: 18 μS/cm
Range: 20 μS/cm
Run time: 10 min

Sodium, ammonium, potassium, calcium, and magnesium ions were detected under the following analytical conditions:

Analytical column: Universal cation column, 7 μm, 100 × 4.6 mm
Mobile phase: 5 mM methane sulfonic acid, pH 4.0
Mobile phase flow rate: 1.0 mL/min
Column temperature: 35 °C
Detector temperature: 35 °C
Injection volume: 100 μL of untreated sample
Offset: 2100 μS/cm
Range: 10 μS/cm
Run time: 7.5 min

Typical chromatograms (left): Chromatogram 1: Inorganic anions in boiler feed water.

Chromatogram 2: Inorganic cations in boiler feed water.

Chromatogram 3: Inorganic anions in steam condensate.

Cecil Instruments Ltd., Milton Technical Centre, Cambridge CB4 6AZ, U.K.; tel.: +44 01223 420821; fax: +44 01223 420475; e-mail: info@ cecilinstruments.com; www.cecilinstruments.com. This note acts purely as a guide to the method. Cecil Instruments Ltd. takes no responsibility for the outcome of any analysis.

Comments