Determination of titanium at μg g^-1 levels in milligram amounts of silicate materials by isotope dilution high resolution inductively coupled plasma mass spectrometry with flow injection

An accurate method for the determination of Ti at μg g^-1 levels in milligram amounts of silicate materials with isotope dilution high-resolution inductively coupled plasma mass spectrometry equipped with flow injection system (ID-FI-HR-ICP-MS) is presented. The chemical procedure requires HF digestion of the sample with the Ti spike, subsequent evaporation and dissolution of Ti with HF in order to separate from Mg and Ca fluorides formed after the digestion of the sample. A 10 mg silicate sample containing 0.002% TiO₂ was measured with a blank correction of <5%. To demonstrate the applicability of this method, peridotite reference materials, PCC-1 and DTS-1, from the US Geological Survey (USGS) and JP-1 from the Geological Survey of Japan (GSJ) were analyzed (12-33 mg), to determine TiO₂ content. The reproducibility was 3% for these peridotites with TiO₂ contents of 0.003-0.004%. This method also gave TiO₂ contents in BCR-1, BHVO-1 and AGV-1 from USGS and JB-1, -2, -3, JA-1, -2, and -3 from GSJ with reproducibility of 1-5% using test portions of 6-18 mg.