An Automated Direct Sample Insertion System for Inductively Coupled Plasma-Atomic Emission Spectrometry

Abstract

An automated direct sample insertion device for inductively coupled plasma-atomic emission spectrometry is described. Graphite cup sample probes can be mechanically inserted into the plasma, and the insertion sequence is completely under computer control via a stepper motor. Multichannel high-speed electronics have been developed for a direct-reading polychromator that allow the real-time digitization of the transient spectral signals from up to six channels simultaneously. A small robot arm is used to automate exchange of the graphite cup sample probes. Custom software has been developed for system control and signal processing. For volatile elements such as Zn and Cd, detection limits are in the pg range for a 10 μL solution sample.