Small spray chamber for inductively coupled plasma atomic emission spectrometry and its evaluation by a digital signal sampling technique

The practical performance of a small single-barrel spray chamber was evaluated with special regard to the response time attained for the discrete nebulisation technique in inductively coupled plasma atomic emission spectrometry. The precision, sensitivity and response times obtained with chambers of various sizes were compared by digital signal sampling and processing using a personal computer. For a precise comparison, two parallel chamber systems, each having an individual chamber, cross-flow nebuliser and drain trap, were switched alternately with a 3-way valve with the plasma on. One system was equipped with the chamber being investigated and the other with a fixed chamber as a reference. The small chamber, 1.8 cm i.d. and 5 cm in length, was recommended for discrete nebulisation, because of its faster response and better precision compared with a chamber of a size normally available commercially. The small chamber also showed good performance characteristics with continuous nebulisation.