NEWS Glass Expansion Newsletter | June 2015 | Issue 37
Glass Expansion News
Application Spotlight
Optimizing the Analysis of Naphtha by ICP-OES
Introduction
Trace metal content in naphtha is important for a number of reasons1. The presence of
metals such as nickel during the cracking process can poison the expensive catalyst, while
vanadium causes corrosion problems. During the refining process, release of toxic metals
such as lead, mercury, and arsenic must be monitored and minimized. The presence of
trace metals is also used to gain insight into the geological origin and migration of crude
oil to aid in exploration. The analysis of naphtha by ICP-OES is complicated by the high
volatility of the sample, which can overload the plasma. It is therefore often diluted with a
suitable solvent such as kerosene or xylene to facilitate the analysis. Unfortunately, due to
the low levels of detection desired, dilution may not always be a viable course of action. In
this paper, we will determine the optimum parameters to analyze naphtha directly without
dilution.
Experimental
An iCAP 6500 Duo ICP spectrometer (ThermoFisher Scientific, Waltham, MA) was used
for all measurements. The following components were incorporated (all from Glass
Expansion, Melbourne, Australia):
• Spray chamber: IsoMist XR Programmable Temperature Spray Chamber
• Torch: D-Torch with alumina inner tube and ceramic outer tube
• Injector: Quartz tapered 1.0mm bore
• Nebulizer: SeaSpray glass concentric with 0.4mL/min uptake
• Pump tubing: Contour Flared-end Solva two tag, Orange/Yellow 0.51mm ID.
The instrument parameters employed are listed here
Plasma gas flow rate (L/min) 16
Auxiliary gas flow rate (L/min) 2
Forward Power (watts) 1350
Nebulizer gas flow rate (L/min) 0.28 and 0.38
Sample uptake rate (mL/min) 0.5
Spray chamber temperature (oC) -10 and -25
The IsoMist XR (Glass Expansion) was used to control spray chamber temperature. The
IsoMist XR has a range of -25oC to +80oC in increments of 1oC and accuracy of + /-0.1oC.
It is controlled with proprietary software via a USB port or wireless Bluetooth® technology.
Photos of the IsoMist XR and the encapsulated glass spray chamber (which resides inside
the IsoMist housing) are shown in Figure 1.
Upcoming Exhibitions and
Conferences
A wide selection of Glass Expansion
products will be on display at the
following exhibitions. 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.
Environmental Measurement
Symposium
Chicago IL, USA, July 13 to 17
(Booth #59)
www.nemc.us/index.php
NY & PA Association of Approved
Environmental Laboratories Annual
Convention (NYPaAAEL)
Corning NY, USA, July 20 to 21
www.nyaael.org/
JASIS 2015
Tokyo, Japan, September 2 to 4
www.jasis.jp/en/
SOS Fluid Analysis 2015
Dealer Conference
Scottsdale AZ, USA, October 5 to 8
Gulf Coast Conference
Houston TX, USA, October 20 to 21
(Booth # 313).
www.gulfcoastconference.com/
In this issue:
• Application Spotlight...................1 – 4
• GE News..............................................1
• New Products................................5 – 6
• Instrument News...........................6 – 7
From Agilent Technologies
From Teledyne Leeman Labs
From Spectro
www.geicp.com 1
/www.geicp.com