Evaluation of several commercially available spray chambers for use in inductively coupled plasma atomic emission spectrometry

Four different spray chambers were compared for the elemental analysis of liquid samples by ICP-AES: a double-pass Scott-type spray chamber made from Ryton and three cyclonic spray chambers manufactured from various materials [i.e.,glass, poly(propylene), PP, and poly (tetrafluoroethylene), PTFE]. A glass concentric pneumatic nebulizer was used in conjunction with all four chambers. The parameters evaluated were: the characteristics bf the aerosols at the exit of each chamber (i.e., tertiary aerosols); the solvent (S-tot) and analyte (W-tot) transported through each chamber; and the ICP-AES analytical parameters (ie., net emission intensities, limits of detection, LOD, and background equivalent concentrations, BEG). The interference produced by the presence of a widely used matrix (ie., acids) was also evaluated for the four chambers. The results indicated that the cyclonic glass and PP spray chambers gave rise to coarser tertiary aerosols, higher solution transport rates, higher emission signals and; lower LOD and BEC values than the other two spray chambers. For the cyclonic spray chambers, the position of the nebulizer proved to be of critical importance. With regard to the acid effects, these were more pronounced as the tertiary aerosols became finer. Hence, for the Scott-type spray chamber, the signal-reduction induced by the presence of acids was enhanced compared with the cyclonic spray chambers.