Abstract

A novel microwave thermospray nebulizer (MWTN), using a TM₀₁₀ resonant cavity 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 thinner quartz outlet capillary located in a TM₀₁₀ cavity. A microwave power of 60 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-pressure pump in a traditional thermospray nebulizer, could be used to transfer the solution. The nebulizer was successfully coupled to an inductively coupled 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 intensity 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.