Abstract
Laser ablation (LA) in analytical chemistry has grown rapidly over the past decade and is becoming a dominant technique for direct solid introduction into inductively coupled plasma mass spectrometry (ICP-MS) in analytical chemistry. The advantages of LA include direct characterization of solids, no chemical procedures for dissolution, reduced risk of contamination or sample loss, analysis of very small sample and determination of spatial distribution of elemental composition. To exploit the possibilities of this technique in analysis of various types of environmental samples, in this study, we developed a dried-droplet method for laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).The proposed method provides accurate and precise results when building calibration curves and determination of elements of interest in the liquid as well as airborne particulate matter samples. After placing just 1 L of a liquid standard solution onto the filter surface and then converting the solution into a very small, thin dry spot, the standard filter sample could be applied as an analytical subject for LA. To demonstrate the feasibility of this method, we used LA-ICP-MS to determine the levels of 13 elements ( Li, V, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) in five water samples and 16 elements (Na, Mg, Al, Si, K, Ca, V, Cr, Mn, Fe, Cu, Zn, As, Sr, Ba and Pb) in airborne particulate matter samples. The correlation coefficients obtained from the various calibration curves ranged from 0.9920 (205Tl) to 0.9998 (52V), sufficient to allow the determination of a wide range of elements in the samples. Quantitative elemental analysis using this LA-ICP-MS technique can be performed within a period short time. In comparison with the established sample introduction by nebulization, the developed method can bring several benefits: no matrix interference, no need for sample pretreatment (time-saving), and reduction of possibilities of sample contamination.