RADIATION VERSUS CONDUCTION IN HEATED SPRAY CHAMBER DESOLVATION FOR INDUCTIVELY COUPLED PLASMAS

A comparative study has been made of the performance of two heated spr ay chamber desolvation systems for sample introduction into inductivel y coupled plasmas. These two systems differed in the way that heat was delivered to the aerosol. The first system used a silica spray chambe r that was embedded in an electrically heated copper block, so that co nductive heat transfer was favoured. The second system used a spray ch amber of the same dimensions and material, but it was placed at the fo cus of a radiant heater. Measurements were made of the sensitivity gai ns, stabilities and sample carryover that were obtained with both syst ems when aqueous solutions were injected using several different nebul izers. The results showed that radiant heating gave better short-term stability and sharply reduced wash-out times and carryover effects.