NEWS Glass Expansion Newsletter | October 2015 | Issue 38
Glass Expansion News
APPLICATION SPOTLIGHT
Performance of In-Line Addition using the TridentTM
Winter Conference
A wide selection of Glass Expansion
products will be on display at the
2016 Winter Conference on Plasma
Spectrochemistry, January 10-16,
2016, Tucson, Arizona, USA.
The display will include nebulizers,
spray chambers, torches, RF coils,
ICP-MS cones and accessories.
Glass Expansion specialists will be
on hand to answer your questions
and assist you to choose the optimum
components for your ICP.
Please visit us at Booth 39.
Internal standards (IS) are often used in ICP optical and mass spectrometry to correct
for matrix based interferences and improve measurement stability.1 Similarly, an ionization
buffer can be utilized for axial view ICPs to suppress the ionization effects of easily ionizable
elements (EIE). Whether an IS or ionization buffer is used, this process involves dosing
each blank, standard, and sample with a known concentration of a particular element (or
elements). When dealing with a large number of samples, this process can be very time
consuming. Other concerns are the risk of contamination and the accuracy of volumetric
In this issue:
addition.
• Application Spotlight................1 – 3
An alternative to premixing the IS or ionization buffer is to add them in-line using a mixing
tee. Glass Expansion developed the Trident In-Line Reagent Addition Kit for this purpose.2
• GE News..........................................1
The Trident allows the IS and/or ionization buffer to be automatically mixed with each sample
• New Products..................................4
during sample introduction, saving considerable sample preparation time and reducing the
• Instrument News.......................5 – 6
risk of error or contamination. The focus of this article is to compare the performance of
From Agilent Technologies
manual addition (offline) to inline addition of an IS using the Trident. We will also investigate
the use of a self-aspirating nebulizer in conjunction with the Trident kit, eliminating the need
From Analytik Jena
for peristaltic pump delivery of the sample and IS.
From Spectro
Experimental:
The operating conditions for an Agilent
5100 ICP-OES are listed in Table 1. In this
Table 1. Agilent 5100 ICP-OES Operating Parameters
experiment, the Trident Kit relies on the
Plasma Gas Flow 12 L/min
instrument peristaltic pump to accurately
Auxiliary Gas Flow 1.0 L/min
dose each sample with an IS or other
RF Power 1350 W
reagent (Figure 1A). The Trident is offered in
two configurations, one kit which includes a
Nebulizer SeaSpray (P/N ARG-07-USS2)
glass tee for solutions which do not contain
Nebulizer Gas Flow 0.75 L/min
HF and another which includes a PFA tee
Nebulizer Flow Rate 1 mL/min (1.4 mL/min
(Figure 1B) for HF-containing samples. Both
self-aspiration)
kits are completely modular so that damaged
0.76mm i.d.
or worn components can easily be replaced.
Peristaltic Pump Tubing - Sample The glass tee was used throughout these
Peristaltic Pump Tubing - IS 0.76mm i.d. (with Trident only)
experiments.
Spray Chamber Twister (P/N 20-809-9199HE)
The heart of each Trident kit is a custom
designed mixing chamber (Figure 2). The tee
provides zero dead volume connections on the input ends for the sample and reagent lines. The output end, however, is designed with a
small mixing chamber so that the sample and reagent are intimately mixed prior to introduction to the nebulizer. The design of the mixing
chamber is vital, and helps the ICP analyst to achieve efficient mixing and maintain a stable ratio of Sample:IS. Other inline mixing devices
have used a coil of capillary tubing after the tee to give the sample and IS time to thoroughly mix. The problem with this approach is that
the coil adds significant overhead to both the front end (stabilization delay) and the back end (washout). However, even with the efficient
built-in mixing chamber of the Trident kit, it is important to note that the instrument stabilization time in the ICP method parameters will
need to be adjusted. The additional time required will depend on the mixing ratio. Typically, the more closely matched are the two peristaltic
pump tubing diameters (sample and IS), the lower the stabilization time. In these experiments an additional 10 seconds was added to the
instrument stabilization time when using the Trident.
www.geicp.com 1
/www.geicp.com