ANALYSIS OF SAMPLES CONTAINING LARGE AMOUNTS OF DISSOLVED SOLIDS USING MICROSAMPLING FLOW-INJECTION INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY

The use of microsampling flow injection inductively coupled plasma mass spectrometry for the multi-elemental analysis of samples containing large amounts of total dissolved solids is described. The flow injection parameters such as sample delivery rate and sample loop volume were optimized with respect to signal peak height and stability. Short- (5 min) and long- (>2 h) term precision of the technique were investigated and detection limits in a 3% m/v NaCl matrix were determined. The detection limits for flow injection were 2-5 times better than those for continuous flow sample aspiration of the same matrix. Standard reference rock material AGV-1 from the United States Geological Survey was analysed after lithium tetraborate fusion (>1.2% m/v salt) to demonstrate the accuracy of the proposed method. Recovery experiments were carried out using spiked (10 mug l-1) 1 and 3% m/v NaCl solutions and were found to be acceptable for such matrices ranging from 83 to 119%.