Inductively coupled plasma isotope analyser

Potassium is analyzed in chemicals that are used in the fertilizer industry and in finished fertilizers by flame photometric methods (44) or volumetric sodium tertraphenylboron methods (45) as approved by the AO AC. Gravimetric deterrnination of potassium as K2PtClg, known as the Lindo-Gladding method (46), and the wet-digestion deterrnination of potassium (47) have been declared surplus methods by the AO AC. Other methods used for control purposes and special analyses include atomic absorption spectrophotometry, inductively coupled plasma (icp) emission spectrophotometry, and a radiometric method based on measuring the radioactivity of the minute amount of the isotope present in all potassium compounds (48). 

Walder AJ, Freedman PA (1992) Isotopic ratio measurement using a double focusing magnetic sector mass analyser with an inductively coupled plasma as an ion somce. J Anal At Spectrom 7 571-575... 

Since about 1990, however, inductively coupled plasma (ICP, see Section 2.1.5) has become increasingly popular at the expense of TI in this area of application [9]. Although TI can provide better results for some analyses, ICP is more versatile and requires less sample preparation effort. Moreover, the advantage of better precision for TI is often compromised by the sample, for example, sample inhomogeneity. Nevertheless, there are still many examples where TI is used, such as for isotope analysis [10-13] and geochronology [14]. 

Douglas DJ, Tanner SC (1998) Fundamental considerations in ICP-MS. In Inductively Coupled Plasma Mass Spectrometry. Montaser A (ed), Wiley-VCH, New York, p 615-679 Eugster O, Tera F, Wasserburg GJ (1969) Isotopic analyses of barium in meteorites and in terrestrial samples. J Geophys Res 74 3897-3908... 

An official method has been published for the determination of nickel in 1M ammonium nitrate extracts of potassium from soil [178]. The level of potassium in the extract is determined by flame photometry. Inductively coupled plasma atomic emission spectrometry (Sect. 2.55) and stable isotope dilution (Sect. 2.55) have been applied to the determination of potassium in multi-metal analyses. 

Figure 4 Schematic diagram of high-pressure liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) system with dual-inlet system for isotope dilution analyses. (From Ref. 32.)...

Hirata, T. (1996) Lead isotopic analyses of NIST standard reference materials using multiple collector inductively coupled plasma mass spectrometry with a modified external correction method for mass discrimination effect. Analyst 121, 1407-1411. 

Materials Characterization Using Elemental and Isotopic Analyses by Inductively Coupled Plasma Mass Spectrometry... 

Laser-ablation, inductively coupled-plasma mass spectrometry (LA-ICPMS) is an instrumental technique in which a laser-ablahon cell and ophcal microscope supplant the spray chamber/nebulizer apparatus of a standard ICP-MS instrument. Subsamples of questioned material are ablated from a solid sample via laser (often a pulsed Nd-YAG tuned to 266 or 213 nm). Ablated specimens are transported in a stream of Ar to a plasma torch for ionization and mass discrimination as per solution ICP-MS. Only minimal sample prep is required, and few restrictions are placed on the nature of questioned solid samples (Brundle et al. 1992 Vickerman 1998). While laser spot sizes can be reduced to several micrometers, sensitivity is degraded as a result, and usual spatial resolutions are on the order of 10-100 pm. Matrix-matched standards are also necessary for accurate trace-element and isotopic quantitative analyses in LA-ICPMS. Depending on the quality of such primary standards, LA-ICPMS accuracies are typically 1-10%, with limits-of-detection in the parts-per-billion (ppb) range (O Table 62.1). 

Characterisation of ancient and art nouveau glass samples by Pb isotopic analyses using laser ablation coupled to a magnetic sector field inductively coupled plasma mass spectrometer. J. Anal. At. Spectrom.,... 

Inductively Coupled Plasma-Mass Spectrometry (ICPMS), A major advance in analyses of both lead concentrations and isotopic compositions has been the development of ICPMS. Since the first commercial instrument was introduced in 1983 (Houk and Thompson 1988), this method has rapidly assumed a prominent position in many research laboratories (e.g., Barnes 1991 Hieftje and Vickers 1989). Inductively coupled plasma-mass spectrometers, in which the sample is introduced into a plasma with excitation temperatures (> 5000°K) that efficiently atomize and ionize lead into a mass spectrometer (quadrapole or magnetic sector), are becoming relatively inexpensive and efficient alternatives to TIMS and other established methods (AAS, XRFA, ASV, ICP-AES) (Barnes 1991 Delves and Campbell 1988). 

Hirata, T., Hattori, Michinari Tanaka, and Tsuyoshi (1998) In-situ osmium isotope ratio analyses of iridosmines by laser ablation-multiple collector-inductively coupled plasma mass spectrometry. Chem. Geol., 144, 269-80. 

In inductively coupled plasma mass spectrometry analysis, the sample is heated in an argon-plasma activated by a high-voltage field. Thereby, atoms are ionized. Using an electric field, the generated ions are accelerated to the analyser of the mass spectrometer, where they are separated according to the mass of the specific isotopes. In inductively coupled plasma optical emission spectroscopy (ICP-OES), also referred to as inductively coupled plasma atomic emission spectroscopy (ICP-AES), the sample is atomized in argon plasma and the excitation of an optical emission of cadmium is measured. 

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