Ot. Akinbo et Jw. Carnahan, EFFECTS OF A MEMBRANE DESOLVATOR ON THE ANALYTICAL PERFORMANCE OF A 120 W HELIUM MICROWAVE-INDUCED PLASMA - AQUEOUS DESOLVATION, Applied spectroscopy, 52(8), 1998, pp. 1079-1085
The effect of a flat-sheet membrane desolvator (FSMD) on the analytica
l performance of a low-power (120 W) He-MIP (helium microwave-induced
plasma) is examined. Ultrasonic nebulization with conventional desolva
tion of an aqueous solution resulted in a dull, red, unstable plasma t
hat was extinguished if the carrier gas how rate was greater than 1.2
L/min. Using the FSMD with this system resulted in an enhancement of t
he plasma stability and a significant reduction of the reddish emissio
n from hydrogen atoms. Also, without the FSMD, only weak chlorine emis
sion signals were observed when 1000 ppm aqueous Cl solution was nebul
ized, but with the FSMD intense chlorine signals were observed with a
detection limit of 1.0 mu g/mL. Sensitivity improvement factors for Cu
, B, P, Cd, and Ph ranged from 1.5 to 20. Greater improvements were se
en for ''harder to excite'' elements.