Instruments
Plasmaquad 2
This instrument was introduced in 1987 by VG Elemental and was discontinued in 1996 by Fisons Instruments. The first generation was configured and performed very similarly to the PQ1 with subsequent versions designed with some new enhancements. A new electron multiplier preamplifier extended the dynamic range by an additional three orders of magnitude. The vacuum tube based 12-12 quadrupole system were replaced with the SXP300 solid-state electronics, and turbomolecular pumps replaced the diffusion pumps for the vacuum chamber. 1990 saw the introduction of the STE instrument electronics controller and the 2KW solid state ICP RF generator. A new high performance interface design offered improved cooling and pumping of the expansion region between the cones that improved sensitivity and backgrounds. PQ-vision software was written for IBM's OS/2 operating system and shipped with the instrument. However, Plasmalab, a WindowsNT software package, is now available as an upgrade. Instrument sensitivity was at least 20 mcps/ppm in the standard configuration to over 200 Mcps/ppm when used with some additional performance upgrades. This instrument was later named the PQS because it has become quite different in it's look and capability from the first generation PQ2.
The PQ2/S is still being used by a large number of our clients so we have gone to great lengths to be able to maintain an inventory and create a bench repair facility. If you need a part replaced or tested then we can accommodate you using our PQ2. All SXP300 quadrupoles and quadrupole electronics will come with test data clearly showing peak shapes and precision statistics.
We also offer some performance upgrades such as the high performance interface, the S-option which is a large capacity rotary pump for the expansion interface region, an organics option for analyzing organic matrices, a solid-state RF generator to replace the Henry generator, Edwards active vacuum gauges for improved reliability and a turbomolecular pumping system to replace diffusion pumps.
Plasmaquad 3
This instrument was introduced in 1996. The primary improvements were that the STE instrument electronics controller was replaced by commercially available programmable logic controller components. A fully automated torch alignment platform in the X, Y, and Z directions was used and an insertable torch screen could be fitted for use in cool plasma experiments. The vacuum system was all Edward's turbomolecular and rotary pumps and the lens stack was modified for improved sensitivity and background. The quadrupole and quadrupole electronics were redesigned for improved stability and ion transmission, and a dual-mode electron multiplier system in which analog and pulse counting is conducted simultaneously, became available. The physical size of the instrument was reduced to the size of a large table and the noise level reduced dramatically. Instrument sensitivity for a standard PQ3 using standard pneumatic nebulization was in the range of 30-60 Mcps/ppm. Using the optional S-option pumping mode, sensitivity could be increased to 150 to 300 Mcps/ppm depending on the element. Instrument background was 10 cps at 220 amu.
The PQ3 design moved away from the PQ2 individual units/draws concept used to control its localized functions. Although there are benefits from replacing major units (easy fixes), they tend to be larger and more expensive. The PQ3 uses many more commercially available components allowing it to be fixed more inexpensively. Ionflight has sourced all of these available parts and has built a great inventory. For the components that have now become obsolete, we have found proven alternatives so you can be assured that we will have you covered.
PQ ExCell
Introduced in 1999, the PQ ExCell was packaged in the same cabinet as the PQ3 but the addition of the infinity lens and the Peltier-cooled sample introduction system made a considerable improvement to the instrument's sensitivity and background. The infinity lens consists of a hexapole ion guide biased by mass-dependent RF voltages that optimize ion transmission across the mass range. A chicane deflector replaced the photon stop in the lens optics that helped maintain maximum ion current from sampling interface to electron multiplier. Instrument sensitivity was at least 30 Mcps/ppm for Lithium and Uranium and 60 Mcps/ppm at Indium. Since the ExCell's background was typically less than 0.5 cps, the signal to noise ratio had been improved by a factor of 20 compared to the PQ3. Additionally, the infinity lens could be pressurized with a gas such as helium allowing for collision cell experiments. The introduction of a collision gas reduces typical argon-based interferences that make the analysis of some elements difficult. The collision cell component was available with the standard Excell as an option.
Because the PQ ExCell and PQ3 are very similar we have essentially the same components available to you.
VG Axiom
The VG Axiom was developed in 1996 and was a descendent of the VG Plasmatrace product that was lost when Thermo purchased Fisons Instruments. It is a double focusing magnetic sector high resolution mass spectrometer. It came in both single collector and multi collector configurations and had variable resolution which provided more precise mass separation whilst maintaining the maximum ion transmission. The multicollector had 9 moveable faraday collectors which are used for isotope ratio measurements. Sensitivity was in the reigon of 800 Mcps/ppm with a background of less than 0.1 cps.
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