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 extr acted 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 (a vailable as a standard commercial welding gas) to prevent oxidation. T he detection system is a miniature charge-coupled device (CCD) spectro meter mounted on a PC board. The device is controlled by a laptop comp uter. Background correction measurements are performed by the near-lin e 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 determ ination of Cd in urine, soil, and stream water are typically better th an 90%, with relative standard deviations in the 10% range.