Determination of cadmium with a portable, battery-powered tungsten coil atomic absorption spectrometer

A portable atomic absorption spectrometer is described that is powered by a 12 V car battery. The atomization device is a tungsten coil extracted from a common projector lamp bulb. The coil is housed in a glass cell, and the atomization environment is purged with 10% H-2 in Ar (available as a standard commercial welding gas) to prevent oxidation. The detection system is a miniature charge-coupled device (CCD) spectrometer mounted on a PC board. The device is controlled by a laptop computer. Background correction measurements are performed by the near-line method. Aqueous standard solutions provide a Cd detection limit of 3 mu g/L (60 pg) for a 20 mu L sample volume. Accuracies for the determination of Cd in urine, soil, and stream water are typically better than 90%, with relative standard deviations in the 10% range.