Determination of Barium in Seawater by a Standard Addition Method Adapted to the Direct Current Echelle Optical Emission Spectrometer

摘要

A technique for determining trace concentrations of barium in seawater is described. Analyses are performed using an optical emission spectrometer/spectrograph equipped with an echelle monochromator and a dc argon plasma excitation source. Calibration is done by the addition method. Three portions of each sample are used for each determination. Each of these is mixed in a 9:1 volumetric ratio with a solution containing 2% (w/v) lithium and either 0, 200, or 400 mu g of barium per liter. The instrumental response to 0 mu g of barium per liter is estimated using a 0.2% (w/v) solution of lithium in deionized distilled water as a blank. The accuracy of results obtained in this study is assessed by comparing them with replicate data previously obtained by another investigator using isotope dilution mass spectrometry. The detection limit of the present method is approx. 2 mu g/L. Near this limit, the RSD ranged from 13 to 27%. (ERA citation 07:011370)