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Did I hear you say -
"Exo-Chambers" ? !
Yes, you certainly did ... by this we mean spray chambers that -
(1) may be physically remote to the ICP torch, and that
(2) generally have a reduced level of solvent in aerosol output.
Examples of these are ESI's Apex and PC3.
Are these spray chambers supplied with hardware for their connection ?
Yes, all these spray chambers are supplied by EPOND with
standard connectors
that suit the ICP instrument intended.
My 'Althea' spray chamber has been
broken ! Can it be fixed ?
In some cases, yes. Wash it clean of any contamination and Post it to
EPOND Switzerland.
If the cost of a chamber repair exceeds 30% of its initial purchase price,
you'll receive an email asking for permission to proceed.
What is the purpose of an -
Auxiliary Argon Port on a spray chamber ?
The benefits are three-fold :
(1) total argon flow is no longer dictated by the nebulizer alone,
(2) another gas such as oxygen can be added for organic samples and
(3) an additional desolvation can be achieved in the chamber
How can the stability of a spray chamber be maximized ?
Essentially by preserving the fluid-dynamic character of the spray chamber's internal surfaces and by
'tuning'.
The first of these requirements is met equally by good spray chamber design and proper upkeep of the
chamber.
The second requirement is met by judicious selection of operating parameters -
choices guided by the chamber designers and experience of the instrument user.
Ensure that all connections are gas-tight
- even small leaks of air into the chamber can degrade stability and can cause
plasma ingition difficulty.
Can a Tyfoon
nebulizer be used with
HF-resistant spray chambers ?
Yes, but the results could be far from optimum. Nebulizers for HF-resistant spray chambers should themselves
be HF-resistant, such as ESI's MicroFlow or PFA-ST concentric nebulizers,
the Burgnener MiraMist or EPOND's
No-Break Nebulizers.
The Tyfoon, being a glass nebulizer, is intended for use with glass and quartz spray chambers.
Can you suggest a reference work on ICP sample introduction ?
Yes - a good recent one : 'Liquid Sample Introduction in ICP Spectrometry - a practical guide',
by J-L. Todoli and J-M. Mermet, Elsevier 2008.
What benefits come with a
PC3 electrically thermostatted spray chamber ?
Improved stability and lower solvent throughput - giving lower oxide interferences
... and of course there are
the practical benefits of being able to set the spray chamber temperature
at a constant low level without the need for a bulky, noisy liquid cooler
and its circulating tubes.
The PC3 can be set to one of two temperatures that are programmed at manufacture.
The lowest programmable temperature is -20 deg.C., with the 'PC3-LT' version
Do cyclonic spray chambers have a lower 'memory-effect'
than other types of spray chambers ?
Yes - usually - numerous studies have reported this, as well as
lower 'matrix-effects'.
There have been exceptions though - where coaxial spray chambers have consistently shown better performance :
Several ICP instrument manufacturers offer coaxial chambers as standard,
after their own prolonged and careful evaluations.
What is better - pumped draining of a spray chamber or draining by gravity ?
Problems can arise with both draining methods, so there is no clear advantage either way.
If a spare peristaltic-pump channel is available, it's probably a good idea to make use of it for imposing regular
drainage.
Does heating of a spray chamber give some benefits ?
No, not by itself : the increased evaporation creates vapour-formation instabilities
and condensate-plugs in the ICP torch injector ... this plays havoc with ICP analyses.
Evaporated solvent should be extracted without removing
the analyte itself ... so-called desolvation.
To obtain the full benefits of desolvation EPOND recommends ESI's APEX or microFAST systems :
There's a considerable body of information about them in journals such as the
JAAS
and the
archives of Mike Cheatham's PlasmaChem
bulletin board.
The 2 ESI desolvation systems are the
APEX-Q and APEX-E
high-sensitivity sample introduction systems.
Does EPOND supply components outside of those used with ICP instruments ?
Yes. Take a look at the EPOND site
: you'll see that there
is a wide range of other spectroscopy components,
as well as complete AAS, Infra-Red and UV-VIS instruments.
If you have any less-frequently asked questions, please email - an answer will arrive quickly.
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EPOND Switzerland
Aerosol Technology
C.P. 389
CH - 1800 Vevey
Switzerland
tel.: +41 21 921 29 41
fax : +41 21 921 44 08
email
info @ spray-chamber. com
for any less-frequently asked questions.
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