ANALYSIS OF MAJOR CATION SPECIES IN GREAT BAY ESTUARY WATER

Six cation species, lithium, sodium, ammonium, potassium, magnesium, and calcium ions, in the Great Bay estuary waters were analyzed using ion exchange chromatography the in cation mode. An existing method for six cation determination was modified and used for analysis. Estuary sample collection sites were carefully selected based on expected maximum range in salinity. These sites include the Little Egg Harbor Inlet, the mouth of the Mullica River, the Wading River, and further up the estuary at the fresh water marine water interface. Seven samples were analyzed using an ICS(5000) fitted with a cation analytical column( Dionex CS16), guard column (Dionex CG 16 guard column) and attached auto sampler. A 30mM methanesulfonic acid (MSA) mobile phase combined with a conduction suppressor at 88 mA, and a sample injection volume of 25μl yielded satisfactory separations. The results were consistent with the expected salinity variations in the samples. This method establishes the protocol for IC analysis for future samples. This method will have prolonged use in the Marine Science Course where further testing will be done to link salinity to trace elements.