DETERMINATION OF BARIUM IN SEAWATER USING VANADIUM SILICON MODIFIER AND DIRECT INJECTION GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

Barium is determined in seawater by direct injection Zeeman modulated graphite furnace atomic absorption spectrometry. The V2O5/Si modifier added to undiluted seawater samples promotes injection, sample drying, graphite tube life, and the elimination of most seawater components In a slow char at 1150–1200 °C. Atomlzation Is at 2600 °C. Detection is at 553.6 nm, and calibration Is by peak area. Sensitivity is 0.8 absorbance s/ng (M0= 5.6 pg/0.0044 absorbance s) at an Internal argon flow of 60 mL/min. Detection limit is 2.5 pg (1 standard deviation) Ba In a 25-μL sample. Precision is 1–2% and accuracy is 2–3% for natural seawater (5.6–28 μg L−1). The method works well In organic-rich seawater matrices and sediment porewaters. © 1990, American Chemical Society. All rights reserved.