NEWS Glass Expansion Newsletter | June 2010 | Issue 22
GE NEWS
App lica tion Spo tlig ht
Dea ling wi th Hig h Salt Matrices
Introduction
In the very first issue of this newsletter in
2003, we focused on the analysis of high
salt samples by ICP spectrometry. Since
that time, there have been significant
enhancements to both the spectrometers
and the sample introduction systems that
accompany them and so it is worthwhile
to review this very common application.
The challenges created by high salt
samples are numerous.
• Elevated background levels
for ICP-OES
• Space/charge interferences for ICP-MS
• Polyatomic spectral interferences
for ICP-MS
• Matrix suppressions in general
• Easily ionizable element interferences
for ICP-OES
• Devitrification of quartz components
• Salt deposits in nebulizers and injectors
• Reduced lifetimes of consumables
• Carryover and memory effects
In 2003, it was generally recommended
not to exceed 0.1 or 0.2% total dissolved
solids (TDS) on an ICP-MS. Now much
higher concentrations are routinely
analyzed, an indication of the evolution of
ICP-MS. In this article, we will examine the
challenges listed above with an eye toward
describing the best solutions.
Elevated background levels
for ICP-OES
From an accuracy standpoint, one of
the most significant features provided
by array detectors is the improved
background correction afforded by the
simultaneous measurement of both signal
and background intensities. Previously with
PMT based sequential spectrometers, not
only did the spectrometer measure the
analyte intensities sequentially but also
the background correction point for each
analyte was measured at a different time
than the analyte intensity itself.
Even though simultaneous “direct readers”
measured the analyte intensities at the
same time, a feature such as a stepper
motor was used to measure off-peak
background intensity sequentially.
The simultaneous background correction
capability of array detectors increases
the accuracy of measurement even
when the background is elevated by
the presence of high salt concentrations.
Figure 1 shows an elevated background
situation,(1) one in which simultaneous
correction is advantageous. This graphic
depicts an overlay of several scans on an
iCAP6000 Series ICP (Thermo Scientific,
Cambridge, UK) which utilizes a charge
injection device (CID) array detector.
The background points on the left
and right of the peak are measured
concurrently with the analyte peak itself.
JAIMA Show 2010
A full range of Glass Expansion products
will be on display at the JAIMA Show,
Tokyo, Japan, September 1 to 3, 2010
and Glass Expansion specialists will be
on hand to assist you.
Applications Notes
To assist you with your applications,
we have added a new Applications
Notes section to our website.
Click here to see the first Applications
Notes. We will be adding more over time.
In this iss ue:
• Application Spotlight 1 – 3
• GE News 1
• New Products 4
• Instrument News 5
- From PerkinElmer
- From Spectro
- From Teledyne Leeman Labs
- From Thermo Fisher Scientific
Figure 1: Effect of a complex matrix on an antimony peak at 206.833nm.
www.geicp.com page 1
/www.geicp.com
/wrapper.pl?c1=News_application_notes
/www.geicp.com