120th General Meeting of the KCS

Type Symposium
Area [Analytical Chemistry Division - JASIS (Japan) Joint Symposium] Elemental Analysis Using Plasma Spectroscopy and Mass Spectrometry
Room No. Room C308+C309
Time FRI 15:10-:
Code ANAL-3
Subject Surface-Enhanced Laser-Induced Breakdown Spectroscopy for Liquid Analysis
Authors Yonghoon Lee
Department of Chemistry, Mokpo National University, Korea
Abstract For liquid samples in small amounts, it is very important to obtain repeated measurements with high precision enough to be accepted for a specific application. Usually, bio-fluid or forensic samples such as blood, urine, etc. are provided for analysis in limited amounts. We devised a laser-patterned silicon wafer (LPSW) substrate to spread a water (or aqueous solution) droplet in the pre-defined region. This makes it possible to get several reproducible measurements for a single droplet sample. By spreading the droplet on the laser-patterned area and drying it, the residues can be distributed very homogeneously. This capability of the LPSW substrate is very useful for the elemental analysis techniques for water droplets using laser-ablation sampling such as laser-induced breakdown spectroscopy (LIBS) and laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS). The relatively more homogeneous distribution of dry residues on the LPSW substrate in comparison with that on the bare silicon wafer substrate was found to be due to enhanced hydrophilic attraction between the water droplet and the substrate surface. The capillary interaction using the laser-produced trenches can be suggested as the underlying mechanism of the enhanced surface hydrophilicity. Also, the higher density of laser-produced trenches on the substrate leads to the larger accumulated emission intensities observed in LIBS spectra. This can be attributed to the higher laser sampling efficiency due to the more homogenous distribution of dry residues that decreases the possibility of missing spots where the residues are concentrated. Performances and applications of this methodology will be discussed.
E-mail yhlee@mokpo.ac.kr