MONITORING AND LABORATORY DIVISION
STANDARD OPERATING PROCEDURE

S.O.P. No. NLB 023 - Determination of Ammonium and Potassium Using Ion Chromatography

SCOPE

This document describes a procedure for quantifying the atmospheric concentration of ammonium and potassium.  The procedure is based on the analysis of suspended particulate matter collected on a filter media with a size selective inlet (SSI) high-volume sampler.

SUMMARY OF METHOD

Atmospheric suspended particulate matter is collected over a 24-hour period on a (8 x 10 inch) quartz fiber filter.  The filter is aspirated with a size selective inlet high volume sampler.  A quarter of the filter is extracted in deionized water, filtered, and injected into an ion exchange chromatographic column.  After separation, the ammomium and potassium cations pass through an electronic suppressor to eliminate background conductivity and are then detected with a conductivity cell.  The resultant peaks are identified by their characteristic retention times and quantified by reference to external standards.

Appendix 1 is a set of detailed instructions for routine operation of our Dionex 4000 Ion Chromatograph.