NEWS
Figure 2c: Airtight seal of the IsoMist spray chamber in its case Figure 4: PCC Spray Chamber mounted on an Agilent 7700 ICP-MS
manufacturers rely on their standard spray chamber design to be
fitted in a packing foam. This type of design can lead to unstable
temperatures and an uneven temperature with respect to the top
and bottom of the spray chamber.
The importance of a stable spray chamber temperature is
demonstrated by Figure 3, which shows that a spray chamber
temperature change of 1oC can result in a sensitivity change of
3%. In order to ensure an accurate and constant spray chamber
temperature, the IsoMist Programmable Temperature Spray
Chamber is preferable.
Peltier Cooled Cyclonic (PCC) Spray Chamber for Agilent
ICP-MS:
When the best temperature flexibility or temperature stability is
required, we recommend the IsoMist. However, for many ICPMS
applications, a fixed temperature of 2 or 5°C is used with no
required flexibility. For these applications, we recommend the PCC
Spray Chambers for the Agilent 7700/7900/8800 (Figure 4) and
7500 ICP-MS models. The PCC is based on the spray chamber
and Peltier system of the IsoMist but is coupled to the electronics
and water cooling of the Agilent ICP-MS and operated via Agilent
software. Therefore Agilent 7700/7900/8800 and 7500 users can
get the benefit of a cyclonic spray chamber, faster washout and
increased sample throughput compared to the Scott style spray
chamber.
Evolution of the Spray Chamber-Nebulizer Interface:
The interface between the nebulizer and the spray chamber in an
ICP spectrometer needs to fulfill several criteria:
1. Seal the spray chamber from the external environment
2. Ensure that the nebulizer is always in the same position
3. Allow the nebulizer to be easily removed to be cleaned or
replaced
4. Not contaminate the sample
5. Minimize carryover from one sample to the next
With early spray chambers, an attempt was made to satisfy
these criteria by constructing the spray chamber with a glass arm
Figure 3: Average normalized intensity of 18 analyte lines vs. spray chamber temperature containing grooves for o’rings as shown in Figure 5A.
Evolution of the Spray Chamber-Nebulizer Interface:
Figure 5: Progression of spray chamber-nebulizer interfaces; all glass with o’rings (A), plastic adaptor with o’rings (B), and Helix o’ring-free adaptor (C).
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