Inductively coupled plasma mass source

Jackson SE, Gunther D (2003) The nature and sources of laser induced isotopic fractionation in laser ablation-multicollector-inductively coupled plasma-mass spectrometry. J Anal At Spectrom 18 205-212 Jiang S-J, Houk RS, Stevens MA (1988) Alleviation of overlap interferences for determination of potassium isotope ratios by Inductively-Coupled Plasma Mass Spectrometry. Anal Chem 60 1217-1220 Lam JWH, Horlick G (1990) A comparison of argon and mixed gas plasmas for inductively coupled plasma-mass spectrometry. Spectrochim Acta Part B 45 1313-1325 Langmuir I, Kingdon KH(1925) Thermionic effects caused by vapours of alkali metals. Phil Trans R Soc A107 61-79... 

Sun XF, Ting BTG, Zeisel SH, Janghorbani M (1987) Accurate measurement of stable isotopes of lifiiium by inductively coupled plasma mass spectrometry. Analyst 112 1223-1228 Svec HJ, Anderson AR (1965) The absolute abimdances of the lithium isotopes in natiwal sources. Geochim... 

Inductively coupled plasma mass spectrometry (ICP-MS) is the marriage of two well established techniques, namely the inductively coupled plasma and mass spectrometry. The ICP has been described as an ideal ion source for inorganic mass spectrometry. The high temperature of the ICP ensures almost complete decomposition of the sample into its constituent atoms, and the ionization conditions within the ICP result in highly efficient ionization of most elements in the Periodic Table and, importantly, these ions are almost exclusively singly charged. 

Inductively coupled-plasma mass spectrometers (ICPMS) are relatively new to cosmochemistry, although they have been widely used in other fields. The plasma source makes most of the periodic table accessible to measurement, so several radioactive isotope systems that used to be impractical to use for chronology are now routinely used (see Chapters 8 and 9). 

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.)...

To refine potential Olivella source zones to more specific sections of the coastline, we have employed two different archaeometric techniques, including determination of elemental composition by inductively coupled plasma-mass spectrometry (ICP-MS) and the use of carbon and oxygen stable isotopes using an isotope ratio-mass spectrometer (IR-MS) (38). Each of these techniques is described below, and the final section evaluates and compares their utility in sourcing Olivella shell beads. 

Since the mid-1960s, a variety of analytical chemistry techniques have been used to characterize obsidian sources and artifacts for provenance research (4, 32-36). The most common of these methods include optical emission spectroscopy (OES), atomic absorption spectroscopy (AAS), particle-induced X-ray emission spectroscopy (PIXE), inductively coupled plasma-mass spectrometry (ICP-MS), laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray fluorescence spectroscopy (XRF), and neutron activation analysis (NAA). When selecting a method of analysis for obsidian, one must consider accuracy, precision, cost, promptness of results, existence of comparative data, and availability. Most of the above-mentioned techniques are capable of determining a number of elements, but some of the methods are more labor-intensive, more destructive, and less precise than others. The two methods with the longest and most successful histoty of success for obsidian provenance research are XRF and NAA. 

In this method the soil sample is dried overnight at 85 °C and ground into an homogeneous mixture. A 1 g soil sample is placed into a beaker and 10 ml of concentrated nitric acid added. The solution is heated to dryness and 5 ml of concentrated nitric acid is added. The uranium is redissolved in 5 ml of 8 N nitric acid and diluted to 25 ml with distilled water. The inductively coupled plasma mass spectrometry system used was an ELAN Model 250. The ion source consists of a modified plasma Thermal Model 2500 control box. The forward power was set at 1200 W with the plasma flow, auxiliary flow and nebuliser pressure set at 131/min, 1.0l/min and 0.27 MPa, respectively. The focusing lenses B, El, P and S2 are set at +5.3 V, -12.5 V, -18.0 V and -7.6 V, respectively. The m/z238 ion was monitored for two sec-... 

Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful technique that uses an inductively coupled plasma as an ion source and a mass spectrometer as an ion analyzer. It can measure the presence of more than 75 elements in a single scan, and can achieve detection limits down to parts per trillion (ppt) levels for many elements—levels that are two or three orders of magnitude lower than those obtained by ICP-AES (Keeler 1991). It is more expensive than ICP-AES and requires more highly skilled technical operation. Aluminum levels in urine and saliva were detected down to 0.02 g/mL and in blood serum to 0.001 g/mL using ICP-MS (Ward 1989). Speciation studies have employed ICP-MS as a detector for aluminum in tissue fractions separated by size-exclusion chromatography (SEC) with detection limits of 0.04 g/g in femur, kidney and brain (Owen et al. 1994). 

A plasma source was coupled to a TOF-MS as early as the 1960s, when workers at Bendix [12] used such an arrangement to analyze the chemical species in a plasma jet. The instrument utilized a pulsed supersonic inlet probe similar to that found in current inductively coupled plasma mass spectrometry (ICP-MS) quadru-pole instruments and employed a TOF-MS that was oriented at a 90° angle to the input ion beam. More importantly, however, it used a pulsed extraction field to extract ions from the plasma source and accelerate them into the flight tube. It is this concept of injecting discrete ion bunches into the TOF-MS analyzer that has been almost ubiquitously employed by workers using continuous ion sources [17,18]. 

L. M. W. Owen, H. M. Crews, R. C. Massey, N. J. Bishop, Determination of copper, zinc and aluminium from dietary sources in the femur, brain and kidney of guinea pigs and a study of some elements in in vivo intestinal digesta by size-exclusion chromatographyD inductively coupled plasma mass spectrometry, Analyst, 120 (1995), 705D712. 

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