Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271–453nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24μgL−1, and a relative standard deviation of 3%. •The use of an Acousto-Optic Tunable Filter (AOTF) as monochromator element in WC AAS is presented for the first time.•The system includes the possibility of using one or two parallel coils.•We propose a new atomization cell design, manufactured on PTFE with reduced size.•The temperature of the coils and the atomic clouds of Pb and Cr were observed synchronously with high temporal resolution.