Inductively coupled plasma sample introduction

Stewart, 1.1, and Olesik, J. W. (1998) The effect of nitric acid concentration and nebulizer gas flow retes on aerosol properties and transport rates in inductively coupled plasma sample introduction. J. Anal At. Spectrom., 13,1249-56. 

To examine a sample by inductively coupled plasma mass spectrometry (ICP/MS) or inductively coupled plasma atomic-emission spectroscopy (ICP/AES) the sample must be transported into the flame of a plasma torch. Once in the flame, sample molecules are literally ripped apart to form ions of their constituent elements. These fragmentation and ionization processes are described in Chapters 6 and 14. To introduce samples into the center of the (plasma) flame, they must be transported there as gases, as finely dispersed droplets of a solution, or as fine particulate matter. The various methods of sample introduction are described here in three parts — A, B, and C Chapters 15, 16, and 17 — to cover gases, solutions (liquids), and solids. Some types of sample inlets are multipurpose and can be used with gases and liquids or with liquids and solids, but others have been designed specifically for only one kind of analysis. However, the principles governing the operation of inlet systems fall into a small number of categories. This chapter discusses specifically substances that are normally liquids at ambient temperatures. This sort of inlet is the commonest in analytical work. 

Moens L, Verreft P, Boonen S, Vanhaecke F and Dams R (1995) Solid sampling electrothermal vaporization for sample introduction in inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Spectrochim Acta 508 463-475. Mooijman KA, In t Veld PH, Hoekstra JA, Heisterkamp SH, Havelaar AH, Notermans SHW, Roberts D, Griepink B, Maier E (1992) Development of Microbiological Reference Materials. European Commission Report EUR 14375 EN, Community Bureau of Reference, Brussels. 

Gray AL (1985). Solid sample introduction by laser ablation for inductively coupled plasma source mass spectrometry. Analyst 110 551-556... 

An inductively coupled plasma formed by passing argon through a quartz torch is widely used for the mass spectroscopic analysis of metal compounds separated by online HPLC.6 Samples are nebulized on introduction into the interface. Plasma impact evaporates solvent, and atomizes and ionizes the analyte. Applications include separation of organoarsenic compounds on ion-pairing F4PLC and vanadium species on cation exchange. 

D. Beauchemin, D.C. Gregoire, D. Gunther, V. Karanassios, J.-M. Mermet and T.J. Woods (eds), Discrete Sample Introduction Techniques for Inductively Coupled Plasma Mass Spectrometry, Elsevier, Amsterdam (2000). 

Bjorn E, Freeh W, Hoffmann E, Liidke C (1998) Investigation and quantification of spectroscopic interferences from polyatomic species in inductively coupled plasma mass spectrometry using electrothermal vaporization or pneumatic nebulization for sample introduction. Spectrochim Acta 53B 1766... 

Elemental Speciation - New Approaches for Trace Element Analysis Discrete Sample Introduction Techniques for Inductively Coupled Plasma Mass Spectrometry... 

The extension of inductively coupled plasma (ICP) atomic emission spectrometry to seawater analysis has been slow for two major reasons. The first is that the concentrations of almost all trace metals of interest are 1 xg/l or less, below detection limits attainable with conventional pneumatic nebulisation. The second is that the seawater matrix, with some 3.5% dissolved solids, is not compatible with most of the sample introduction systems used with ICP. Thus direct multielemental trace analysis of seawater by ICP-AES is impractical, at least with pneumatic nebulisation. In view of this, a number of alternative strategies can be considered ... 

Sample preparation for analysis by hyphenated methods requires some additional planning when compared to nonhyphenated methods. All steps, extraction, concentration, and final solvent selection must take into consideration and be compatible with all the components of the hyphenated instrumentation. For gas chromatographic methods, all the components in the mixture must be in the gaseous state. For liquid chromatography (LC) or high-performance liquid chromatography (HPLC), the samples of the analytes of interest can be solids or liquids, neutral or charged molecules, or ions, but they must be in solution. If the follow-on analysis is by MS, then each of the analytes may require a different method of introduction into the MS. Metals and metal ions may be introduced by HPLC if they are in solution but commonly are introduced via AAS or inductively coupled plasma (ICP). Other analytes may be directly introduced from HPLC to MS [2],... 

Montaser A, Tan H, lishi II, Nam SFI, CaiM (1991) Argon inductively coupled plasma mass spectrometry with thermospray, ultrasonic, and pneumatic nebulization. Anal Chem 63 2660-2665 Montaser A, Minnich MG, Liu FI, Gustavsson AGT, Browner RF (1998) Fundamental aspects of sample introduction in ICP spectrometry. In Inductively Coupled Plasma Mass Spectrometry. Montaser A (ed), Wiley-VCH, New York, p 335-420... 

CONTENTS Preface, Joseph Sneddon. Analyte Excitation Mechanisms in the Inductively Coupled Plasma, Kuang-Pang Li and J.D. Winefordner. Laser-Induced Ionization Spectrometry, Robert B. Green and Michael D. Seltzer. Sample Introduction in Atomic Spectroscopy, Joseph Sneddon. Background Correction Techniques in Atomic Absorption Spectrometry, G. Delude. Flow Injection Techniques for Atomic Spectrometry, Julian F. Tyson. 

KirkbrightjG. F. Sample introduction, signal generation and noise characteristics for argon inductively-coupled plasma optical emission spectroscopy in Instrumentelle Multielement-analyse (ed.) Sansoni, B., Weinheim, VCH 1985... 

The introduction of inductively coupled plasma (ICP) in inorganic mass spectrometry means that there is an effective ion source operating at atmospheric pressure. Whereas solid mass spectrometric techniques allow direct analysis of solid samples in ICP-MS, the determination of trace impurities or isotope ratios in solid samples is often carried out after digestion and dissolution of the material. For the determination of trace impurities and isotope ratios in liquids, an additional nebulization... 

Various efficient devices have been utilized for sample introduction into an inductive plasma source, for example the application of several nebulizers, hyphenated techniques, hydride generation, laser ablation and electrothermal vaporization. The role of the solution introduction system in an inductively coupled plasma source is to convert the liquid sample into a suitable form (e.g.,... 

Figure 2.12 Overview of different sample introduction systems in an inductively coupled plasma source. (]. S. Becker and H. ]. Dietze, Spectrochim. Acta 53B, 1475 (1998). Reproduced by permission of Elsevier.)...

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.)...

The main common parts of an ICP mass spectrometer as discussed above are the sample introduction system, the inductively coupled plasma (ICP) ion source for desolvation, atomization and ion formation of introduced sample material, and the mass spectrometer including the mass analyzer system for separation of extracted ion beams and a fast ion detection system to register separated ion beams as illustrated in Figure 5.1. 

Because ICP-MS with different instrumentations and sample introduction systems (besides solution nebulization, also laser ablation or hyphenated methods, such as HPLC, CE, SPME) is today the most frequently used analytical technique for precise and accurate isotope ratio measurements, the following section will mainly focus on this form of mass spectrometry with an inductively coupled plasma source. 

A. Lopez-Molinero, O. Mendoza, A. Callizo, P. Chamorro and J. R. Castillo, Chemical vapor generation for sample introduction into inductively coupled plasma atomic emission spectroscopy vaporisation of antimony(III) with bromide. Analyst, 127(10), 2002, 1386-1391. 

A. Lopez-Molinero, A. Villareal, D. Andia, C. Velilla and J. R. Castillo, Volatile germanium tetrachloride for sample introduction and germanium determination by inductively coupled plasma atomic emission spectroscopy, J. Anal. At. Spectrom., 16(7), 2001, 744 749. 

Use of inductively coupled plasma-mass spectrometry (1CP-MS) coupled to a laser-ablation sample introduction system (LA-ICP-MS) as a minimally destructive method for chemical characterization of archaeological materials has gained favor during the past few years. Although still a relatively new analytical technique in archaeology, LA-ICP-MS has been demonstrated to be a productive avenue of research for chemical characterization of obsidian, chert, pottery, painted and glazed surfaces, and human bone and teeth. Archaeological applications of LA-ICP-MS and comparisons with other analytical methods are described. 

---