On-line pre-concentration for the measurement of cadmium in urine by flame atomic absorption spectrometry

The sensitivity for the measurement of cadmium in urine by flame atomic absorption spectrometry was increased 27.7-fold by the use of an on-line alumina microcolumn and a slotted quartz tube. Cadmium in 2.5 ml of sample was trapped on to basic alumina and rapidly eluted with 8%V/V HNO3. The effects of sample pH and column size on performance were investigated. Results obtained with a series of urine specimens compared well with those obtained by electrothermal atomisation atomic absorption spectrometry.