Inductively-coupled plasma optical emission spectrometry

2 Inductively Coupled Plasma-Optical Emission Spectrometry Principles 

Optical emission spectrometry (OES) is based on the production and detection of line spectra emitted during the de-excitation of electrons in an atom when they fall from upper excited energy levels to lower energy levels. The affected electrons are outer electrons. 

Following any necessary sample preparation and work-up, samples are supplied to the instrument as nebulised or vaporised sprays. An ICP generally requires that the elements for analysis are in solution and are delivered to the nebuliser by a peristaltic pump. The nebuliser transforms the aqueous solution into an aerosol (with the aid of the argon gas) 

The intensity of the electron signal is compared to previously measured intensities of known concentrations of the element and a concentration is computed. Each element will have many specific wavelengths in the spectrum that could be used for analysis. Thus, the selection of the best line the analytical application in hand requires considerable experience of ICP wavelengths. 

Although liquid samples are best, if solid samples require analysis there have been a number of developments such as laser ablation that now allow this. Direct sample insertion is also possible where the solid sample is introduced into the plasma on a carbon electrode. 

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Instrumentation for inductively coupled plasma-optical emission spectrometry. 

Lomer, M.C.E. et ah. Determination of titanium dioxide in foods using inductively coupled plasma optical emission spectrometry. Analyst, 125, 2339, 2002. 

Inductively Coupled Plasma Mass Spectrometry Inductively Coupled Plasma Optical Emission Spectrometry Ion Cyclotron Resonance Ion Diffraction... 

Thiel G, Danzer K (1997) Direct analysis of mineral components in wine by inductively coupled plasma optical emission spectrometry (ICP-OES). Fresenius J Anal Chem 357 553... 

Berndt et al. [740] have shown that traces of bismuth, cadmium, copper, cobalt, indium, nickel, lead, thallium, and zinc could be separated from samples of seawater, mineral water, and drinking water by complexation with the ammonium salt of pyrrolidine- 1-dithiocarboxylic acid, followed by filtration through a filter covered with a layer of active carbon. Sample volumes could range from 100 ml to 10 litres. The elements were dissolved in nitric acid and then determined by atomic absorption or inductively coupled plasma optical emission spectrometry. 

Atomic techniques such as atomic absorption spectrometry (AA), inductively coupled plasma-optical emission spectrometry (ICP-OES), and inductively coupled plasma-mass spectrometry (ICP-MS), have been widely used in the pharmaceutical industry for metal analysis.190-192 A content uniformity analysis of a calcium salt API tablet formulation by ICP-AES exhibited significantly improved efficiency and fast analysis time (1 min per sample) compared to an HPLC method.193... 

The samples were air-dried at room temperature, sieved to < 63 pm and analysed by x-ray diffraction (XRD) and scanning electron microscopy combined with an energy dispersive system (SEM-EDS). For chemical analysis, samples were submitted to an extraction with Aqua Regia and analysed by inductively coupled plasma-optical emission spectrometry (ICP/OES). Firing experiments were performed following the procedure described by Brindley Brown (1980). 

Boss, C. B. and Fredeen, K. J. (1999). Concepts, Instrumentation and Techniques in Inductively Coupled Plasma Optical Emission Spectrometry. Norwalk, CO, Perkin Elmer (2nd edn.). 

Tsolakidou, A. and Kilikoglou, V. (2002). Comparative analysis of ancient ceramics by neutron activation analysis, inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry, and X-ray fluorescence. Analytical and... 

Inductively coupled plasma optical emission spectrometry has been applied to the determination of boron in soil extracts in amounts down to 0.5m L 1 [5]. 

Once the sample is in solution in the acid and the digest made up to a standard volume the determination of metals is completed by standard procedures such as atomic absorption spectrometry or inductively coupled plasma optical emission spectrometry. 

Soil samples were wet sieved into (a) 2-4 mm, (b) 1-2 mm, (c) 0.5-1 mm, (d) 250-500 i m, (e) 125-250 am, (f) 63-125 j,m and (g) <63 j.m fractions. A ferruginous/magnetic fraction (m) was also prepared from the 2-4 mm fraction. Soil fractions were crushed, digested with HNO3/HCI/HF/HCIO4 and then analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) for Al, Ca, Cu, Fe, K, Mn, Na, P, S and Zn. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine Ag, As, Cd, Pb and Sb because of the lower detection limits by this method. The mineralogy of selected samples was determined by qualitative X-ray diffractometry. 

T. Kuokkanen, P. Peramaki, 1. Valimaki and H. Ronkkomaki, Determination of heavy metals in waste lubricating oils by inductively coupled plasma-optical emission spectrometry, Int. J. Environ. Anal. Chem., 81(2), 2001, 89-100. 

N. Carrion, M. Murillo, E. Montiel and D. Diaz, Development of a direct hydride generation nebuliser for the determination of selenium by inductively coupled plasma optical emission spectrometry. Spectrochim. Acta, Part B, 58(8), 2003, 1375-1389. 

J. Moreda-Pineiro, E. Alonso-Rodriguez, P. Lopez-Mahia, S. Muniategui-Lorenzo, D. Prada-Rodriguez, A. Moreda-Pineiro and P. Bermejo-Barrera, Determination of major and trace elements in human scalp hair by pressurized-liquid extraction with acetic acid and inductively coupled plasma-optical-emission spectrometry. Anal. Bioanal. Chem., 388(2), 2007, 441 449. 

M. Grotti, C. Lagomarsino and R. Frache, Multivariate study in chemical vapor generation for simultaneous determination of arsenic, antimony, bismuth, germanium, tin, selenium, tellurium and mercury by inductively coupled plasma optical emission spectrometry, J. Anal. At. Spectrom., 20(12), 2005, 1365-1373. 

A. M. Grotti, Improving the analytical performances of inductively coupled plasma optical emission spectrometry by multivariate analysis techniques, Ann. Chim. (Rome), 94, 2004, 1-15. 

K. Krengel-Rothensee, U. Richter and P. Heitland, Low-level determination of non-metals (Cl, Br, I, S, P) in waste oils by inductively coupled plasma optical emission spectrometry using prominent spectral lines in the 130-190 nm range, J. Anal. At. Spectrom., 14, 1999, 699-702. 

Inductively coupled plasma (ICP) needs careful extraction of the relevant information to obtain satisfactory models and several chemometric studies were found. Indeed, many ICP spectroscopists have applied multivariate regression and other multivariate methods to a number of problems. An excellent review has recently been published on chemometric modelling and applications of inductively coupled plasma optical emission spectrometry (ICP-OES) [79]. 

Atomic emission spectrometry is not sufficiently sensitive to determining molybdenum at the levels at which it occurs in soils. Due to its greater intrinsic sensitivity, inductively coupled plasma atomic emission spectrometry is capable of achieving the required sensitivity. Manzoori [168] has utilised inductively coupled plasma optical emission spectrometry to determine down to 0.01 mg/1 molybdenum in 1 M ammonium acetate extracts of soils. 

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