Laser-induced fluorescence in a graphite furnace as a sensitive technique for assessment of traces in North Arctic atmospheric aerosol samples

Abstract

An improved version of the highly sensitive laser-based spectroscopic trace-element detection technique, laser-induced fluorescence in a graphite furnace, LIF–GF (often also referred to as laser-excited atomic fluorescence spectrometry in electrothermal atomizer, ETA–LEAFS) has been used to assess the trace-element content of Al and Pb in size-fractionated aerosol samples from the Norwegian Arctic. The ordinary LIF–GF technique has been modified for improved selectivity by the incorporation of a multi-channel intensified CCD detector (ICCD) which makes constant monitoring of various background signals possible (scattered laser light, concomitant fluorescence light, and black body radiation). It is shown that the sensitivity and selectivity of the LIF–GF–ICCD technique is sufficient for efficient detection of the trace contents of Al and Pb in dissolved aerosol samples from the Norwegian Arctic (0–75 pg for each furnace heating). The Al and Pb concentrations in air from Ny Ålesund, Svalbard, at the time of sampling (March–April 1992) were found to be 1–50 ng m^–3.