Cadmium determination in sedimented dust by atomic emission spectrometry with a new radiofrequency capacitively coupled plasma source

A new radiofrequency capacitively coupled plasma source (r.f.CCP) was used for Cd determination in dust samples by atomic emission spectrometry. The plasma torch consists of a molybdenum tube electrode and one or two ring electrodes situated outside the quartz tube. Plasma was operated at 27.12 MHz, at low power (275 W) and low gas consumption (0.4 l min(-1) argon flow). The choice of the optimum operating conditions for Cd determination in dust samples dissolved in acids and pneumatically nebulized is presented. The results obtained in such samples were compared with those obtained by flame atomic absorption spectrometry (FAAS). The matrix effect of NaCl and CaCl2 on Cd emission was also studied depending of the plasma coupling system. The true limit of detection for Cd in dust sample by r.f.CCP-AES is 3 mu g g(-1). Concentration of Cd higher than 10 mu g g(-1) can be determined by the proposed method with a relative standard deviation within the range 5 - 10%. The recovery is 100 +/- 10%.