Determination of barium in marine waters by isotope dilution inductively coupled plasma mass spectrometry

A simple and accurate method is presented for determining barium in marine waters. Equal amounts of an enriched isotope spike and sample are diluted 100-fold with 1% nitric acid. The diluted sample is introduced into an inductively coupled plasma mass spectrometer with a peristaltic pump and the mass region from 135 to 138 is scanned 480 times. The entire procedure takes less than 10 min per sample and is accurate to better than 1% as determined by intercalibration with isotope dilution mass spectrometry.