Abstract
Laser ablation (LA) systems, connected to inductively coupled plasma mass spectrometry (ICP-MS), can be used to ablate solid samples directly for trace and ultra-trace element determination. In this dissertation, we demonstrated the application and development of LA-ICP-MS technique for analysis of multiple elements in whole blood and rare earth elements in water samples. Exquisite ability of LA-ICP-MS technique has been exploited to show its potential in broad range of research area. Firstly, we developed the method for accurate determination of Pb concentrations in blood samples using LA-ICP-MS, with the proposed micro-droplet aqueous standard calibration method. In general, LA-ICP-MS studies are somewhat limited by the lack of matrix-matched standards for calibration purposes. Here we describe aqueous standard calibration and matrix-matched calibration methods. This method was validated by analysis of the reference materials. The lower detection limit was estimated as 0.1 ng mL−1. Subsequently, we describes the method follows the previously statement, and improved the method by applying more elements. The proposed method—using LA-ICP-MS, with calibration using a micro-droplet of an aqueous standards solution—can be applied to accurately determine the concentrations of multi-elements in whole blood samples. With this technique, we simultaneously quantified 13 elements in whole blood: Be, Mn, Co, Ni, Tl, Bi, Sb, Pb, Cu, Zn, Ba, Mg, and Cd. A major advantage of this technique is the small amount of sample required—only 0.5 μL, which is readily obtained from a finger or heel stick. This analytical method requires no sample pretreatment and may be particularly suitable for the rapid screening of large numbers of blood samples. Then, we describe a simple method for simultaneous preconcentration and matrix reduction during the analysis of rare earth elements (REEs) in water samples through LA-ICP-MS. From a systematic investigation of the co-precipitation of REEs using magnesium hydroxide, we optimized the effects of several parameters—the pH, the amount of magnesium, the shaking time, the efficiency of Ba removal, and the sample matrix—to ensure quantitative recoveries. We employed repetitive laser ablation to remove the dried-droplet samples from the filter medium and introduce them into the ICP-MS system for determinations of REEs. The enrichment factors ranged from 8 to 88. The detection limit, at an enrichment factor of 32, ranged from 0.03 to 0.20 pg mL–1. We applied this method to satisfactory determination of REEs in lake water and synthetic seawater samples. Our proposed method for analyzing REEs in real samples is simple and straightforward. The procedure provides excellent preconcentration efficiency, as well as high concentration factors, for analytes in water samples, ensuring the highly sensitive detection of REE analytes.