A low-powered microwave thermospray nebulizer for inductively coupled plasma atomic emission spectrometry

A novel microwave thermospray nebulizer (MWTN), using a TM010 resonant cavi ty as the energy coupling device, is described in this paper. The nebulizer consists of a knotted PTFE capillary (od, 1.3 mm, id, 0.5 mm) and a thinne r quartz outlet capillary located in a TM010 cavity. A microwave power of 6 0 W is enough to nebulize the sample solution. Because of the big diameter of the PTFE capillary, a peristaltic pump, instead of the necessary high-pr essure pump in a traditional thermospray nebulizer, could be used to transf er the solution. The nebulizer was successfully coupled to an inductively c oupled plasma atomic emission spectrometry (ICP-AES) instrument. The effect of various parameters, such as the nature and concentration of the medium, carrier gas flow rate, sample uptake rate and so on, on the emission inten sity of Fe, Mg, V and Cu was studied. Compared with a pneumatic nebulizer, the detection limits for Cu, Fe, Mg, and V were improved by a factor of 2-4 .