Instrumentation inductively coupled plasma mass

In modern times, most analyses are performed on an analytical instrument for, e.g., gas chromatography (GC), high-performance liquid chromatography (HPLC), ultra-violet/visible (UV) or infrared (IR) spectrophotometry, atomic absorption spectrometry, inductively coupled plasma mass spectrometry (ICP-MS), mass spectrometry. Each of these instruments has a limitation on the amount of an analyte that they can detect. This limitation can be expressed as the IDL, which may be defined as the smallest amount of an analyte that can be reliably detected or differentiated from the background on an instrument. 

In contrast to thermal ionization methods, where the tracer added must be of the same element as the analyte, tracers of different elemental composition but similar ionization efficiency can be utilized for inductively coupled plasma mass spectrometry (ICPMS) analysis. Hence, for ICPMS work, uranium can be added to thorium or radium samples as a way of correcting for instrumental mass bias (e g., Luo et al. 1997 Stirling et al. 2001 Pietruszka et al. 2002). The only drawback of this approach is that small inter-element (e g., U vs. Th) biases may be present during ionization or detection that need to be considered and evaluated (e.g., Pietruszka et al. 2002). 

In isotope dilution inductively coupled plasma-mass spectrometry (ID-ICP-MS) the spike, the unspiked and a spiked sample are measured by ICP-MS in order to determine the isotope ratio. Using this technique, more precise and accurate results can be obtained than by using a calibration graph or by standard addition. This is due to elimination of various systematic errors. Isotopes behave identically in most chemical and physical processes. Signal suppression and enhancement due to the matrix in ICP-MS affects both isotopes equally. The same holds for most long-term instrumental fluctuations and drift. Accuracy and precision obtained with ID-ICP-QMS are better than with other ICP-QMS calibration... 

Inductively coupled plasma mass spectrometry is now such an important technique in archaeology, as elsewhere, that we devote a whole chapter to it. There are now a number of different ICP MS modes of operation (solution analysis, laser ablation, multicollector, high resolution) this chapter provides a general overview. Further description of the instrumentation for ICP MS may be found in Harris (1997) and Montaser (1998). Some general applications of solution ICP MS are discussed by Date and Gray (1989), Platzner (1997), and Kennett et al. (2001). 

Zheng, J., Goessler, W., Geiszinger, A., et al. (1997). Multi-element determination in earthworms with instrumental neutron activation analysis and inductively coupled plasma mass spectrometry a comparison. Journal of Radioanalytical and Nuclear Chemistry 223 149-155. 

Turner PJ, Mills DJ, Schroder E, Lapitajs G, Jung G, lacone LA, Haydar DA, Montaser A(1998) Instrumentation for low- and high-resolution ICPMS. In Inductively Coupled Plasma Mass Spectrometry. Montaser A (ed), Wiley-VCH, New York, p 421-501... 

To optimize the applicability of the electrothermal vaporization technique, the most critical requirement is the design of the sample transport mechanism. The sample must be fully vaporized without any decomposition, after desolvation and matrix degradation, and transferred into the plasma. Condensation on the vessel walls or tubing must be avoided and the flow must be slow enough for elements to be atomized efficiently in the plasma itself. A commercial electrothermal vaporizer should provide flexibility and allow the necessary sample pretreatment to introduce a clean sample into the plasma. Several commercial systems are now available, primarily for the newer technique of inductively coupled plasma mass spectroscopy. These are often extremely expensive, so home built or cheaper systems may initially seem attractive. However, the cost of any software and hardware interfacing to couple to the existing instrument should not be underestimated. 

Cations were determined by high-resolution inductively coupled plasma-mass spectrometry (HR-ICPMS), relatively new analytical instrumentation with a large dynamic range and detection limits (DLs) in the low (1-50) parts per trillion (ppt) for most elements. The exceedingly low DLs allow for recognition of elemental variations that are not possible with traditional analytical methods for water. 

The Nickel Producers Environmental Research Association (NiPERA) is sponsoring research on the application of inductively coupled plasma-mass spectroscopy (ICP-MS) to isotopic analysis of nickel in biological samples, on the development of sampling instrumentation for assessing workers exposure to nickel in the nickel industry, and on methods for utilizing newly developed analytical methods, such as laser beam ionization mass spectrometry, for the identification and speciation of nickel compounds in powders and dusts with particular reference to nickel refining. 

Numerous methods have been published for the determination of trace amounts of tellurium (33—42). Instrumental analytical methods (qv) used to determine trace amounts of tellurium include atomic absorption spectrometry, flame, graphite furnace, and hydride generation inductively coupled argon plasma optical emission spectrometry inductively coupled plasma mass spectrometry neutron activation analysis and spectrophotometry (see Mass SPECTROMETRY Spectroscopy, OPTICAL). Other instrumental methods include polarography, potentiometry, emission spectroscopy, x-ray diffraction, and x-ray fluorescence. 

Figure 5.1 Main parts of an inductively coupled plasma mass spectrometer sample introduction systems (left column), e.g., Meinhard or MicroMist nebulizer with cyclonic spray chamber, ultrasonic nebulizer, microconcentric nebulizer and laser ablation system (all from CETAC Technologies), ion source (middle column) and several types of mass spectrometers, (a) Agilent 7500 from Agilent, (b) Platform from CV Instruments, or (c) Element from Thermo Fisher Scientific. (Parts of this figure were reproduced with permission from CETAC Technologies, Agilent, CV Instruments and Thermo Tisher Scientific, respectively.)...

Part X Instrumentation for Inductively Coupled Plasma Mass... 

The success of inductively coupled plasma mass spectrometry (ICP-MS) has resulted in a broad availability of sophisticated instrumentation packages with user-friendly software and sample-analysis cookbooks at reasonable cost [10]. 

Fundamentals and Basic Instrumentation of Inductively Coupled Plasma Mass Spectrometry... 

Figure 21-24 Flame, furnace, and inductively coupled plasma emission and inductively coupled plasma—mass spectrometry detection limils (ng/g = ppb) with instruments from GBC Scientific Equipment, Australia. [Flame, furnace. ICP from R. J. Gill. Am. Lab. November 1993, 24F. ICP-MS from T. T. Nham, Am. Lab. August 1998. 17A Data for Ct Br, and l are from reference 14.] Accurate quantitative analysis requires concentrations 10-100 times greater than the detection limit.

The analyses were carried out at the Field Museum of Natural History in Chicago, IL. The instrumentation is a Varian inductively coupled plasma-mass spectrometer (ICP-MS) equivalent to the actual Varian 810 instrument. A New Wave UP213 laser is connected to the ICP-MS for direct introduction of solid samples. 

Trace elemental analysis of ancient ceramics has been proven a very useful tool for tracing the circulation of this material. Instrumental neutron activation analysis (INAA) was for years the analytical technique of choice to measure the composition of ceramics because of the large number of elements it could determine and its good sensitivity. Lately, a few publications have shown that laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) could provide similar results as INAA more quickly and at lower cost. A protocol has been developed to determine 51 elements using LA-ICP-MS and tested it on Wari period ceramics previously analyzed using INAA. We show how INAA and LA-ICP-MS analysis lead to the same conclusion in terms of sample groupings. 

Kimbrough and Wakakuwa [276,330] reported on an interlaboratory comparison study involving 160 accredited hazardous materials laboratories. Each laboratory performed a mineral acid digestion on five soils spiked with arsenic, cadmium, molybdenum, selenium and thallium. The instrumental detection methods used were inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry, flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry and hydride generation atomic absorption spectrometry. At most concentrations, the results obtained with inductively coupled plasma atomic emission spectrometry... 

The determination of 129I in low-level radioactive waste was accomplished by radioactive instrumental neutron activation analysis [3]. A different group reported the determination of both 129I and 127I by neutron activation analysis and inductively coupled plasma mass spectrometry [4]. The method was very rapid - a sample could be analysed in three minutes. However, interference from 129Xe resulted in limited sensitivity for 129I detection. 

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