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Without IsoMist. IsoMist At 21C. Figure 2: Effect of spray chamber temperature on the % CeO ratio by ICP-MS. Figure 3: Effect of spray chamber temperature on sensitivity using an IsoMist with ICP-OES. Encapsulated spray chamber.
Figure 2: Effect of spray chamber temperature on the % CeO ratio by ICP-MS
Figure 3: Effect of spray chamber temperature on sensitivity using an IsoMist with ICP-OES
Table 1: Consecutive runs (90 minutes apart) of straight naphtha by ICP-OES with IsoMist at -10C
Figure 4: Effect of spray chamber temperature on LOD using an IsoMist with ICP-OES
A New Versatile Programmable Temperature Spray Chamber for ICP
Jerry Dulude and Ron Stux (USA), Vesna Dolic (Australia), Glass Expansion (www.geicp.com)
Low Temperature Applications
Elevated Temperature Applications
Constant Temperature Benefits
For both ICP-OES and ICP-MS, the temperature of the spray chamber can have a profound influence on the ability of the system to achieve high quality results in a variety of sample types. This paper describes a novel system that both monitors and controls spray chamber temperature, and evaluates the device under a variety of conditions for a variety of applications.
All ICP-MS work was performed on a PerkinElmer Elan 6000 and all ICP-OES work on a PerkinElmer Optima 2100 DV.
Two low temperature control applications are investigated.
Reduction of oxide interferences in ICP-MS
Direct aspiration of naphtha, a volatile organic solvent that severely loads the plasma.
Increasing spray chamber temperature increases the transport efficiency of the sample introduction system. At typical uptake rates of 1 to 2 ml per minute, this would result in an unstable plasma. However, when sample volume is limited as is often the case in certain clinical samples, very low uptake rates must be used. In this case increasing the spray chamber temperature will not overload the plasma and will allow lower detection limits to be reached as shown below. Data taken under standard conditions.
Signal drift is closely associated with the drift of spray chamber temperature. Initially as the spectrometer warms up, there is a constant upward drift in temperature. Subsequently, the spray chamber temperature drifts along with the environmental temperature of the laboratory. The figure below shows how stabilizing the spray chamber temperature has a dramatic effect on stabilizing the analytical signal over the long term.
Data generated on a Sciex6000 ICP-MS at 1.1L/min argon nebulizer flow using a Conikal nebulizer and Twister spray chamber. RF power was 1400 watts.
Figure 5: Long-term drift in ICP-OES with and without temperature control
Figure 1: IsoMist™ Programmable Temperature Spray Chamber
DISCUSSION and CONCLUSIONS
1500 watts on PE2100DV; SeaSpray nebulizer and Twister spray chamber; Neb gas at 0.35LPM, uptake at 0.3ml/min; 1mm bore injector. Coolant gas flow was 20LPM; AUX flow was 1.8LPM.