The use of ETV-ICP-MS for the determination of selenium in serum

Abstract

The development of a novel procedure for the accurate determination of selenium in serum using electrothermal vaporisation inductively coupled plasma mass spectrometry (ETV-ICP-MS) is described. The proposed method eliminates the need for a lengthy sample digestion procedure (a requirement with many methods for the analysis of biological samples), utilising a simple 1+19 dilution of the serum with 1% nitric acid. Many of the interferences normally associated with the determination of selenium by ICP-MS are successfully eliminated with careful optimisation of the ETV temperature program and modifier system. Analytical characteristics for 74Se, 77Se, 78Se and 82Se are reported, including detection limits (3s blank) of approximately 0.1 ng g−1 for 77Se and 82Se. Short-and longterm reproducibility data between 4.7 and 4.9% and 3.2 and 3.8% (RSD) for 77Se and 82Se, respectively, are shown. The accuracy of the method, which included Te as an internal standard, was demonstrated with the analysis of three internal quality control samples and the certified reference material NIST SRM 1598 (bovine serum). Results within 10% of the target value were achieved for three of the four isotopes studied, with slightly worse results for 78Se owing to the large interference from argon adduct ions on this isotope. Preliminary work involving the addition of nitrogen to the argon aerosol carrier gas was successful in reducing the ArAr interference at m/z 78. levels of components such as sodium and organic compounds,

Determination of selenium in blood serum by inductively coupled plasma atomic emission spectrometry with pneumatic nebulization

“…Nevertheless, the analysis of whole blood, serum or blood plasma using nebulization has been also reported [3]. Whole blood or serum is diluted by Triton X-100 [7], 1% HNO 3 solution [8], or water [9]. Enzymatic digestion reduces the viscosity of serum [10].…”

“…Enzymatic digestion reduces the viscosity of serum [10]. Samples are introduced into an ICP using conventional [7] or ultrasonic [10] nebulizers, or by electrothermal vaporization [8]. Double-focusing mass spectrometers facilitate the minimization of spectral interferences [9].…”

Accurate analysis of selenium in water and serum using ETV-ICP-MS with isotope dilution

“…ETV-ICP-MS has the advantage of using small sample sizes (5± 50 ml), greater sensitivity and the capability to eliminate some of the polyatomic interferences already mentioned by thermal pre-treatment of the sample. In a previous publication 9 we have described the development of an ETV-ICP-MS procedure for the analysis of selenium in serum. The method successfully overcomes spectroscopic interferences with careful optimisation of the temperature program.…”

Application of Three Spectrometric Methods to Total Selenium Determination in Postmortem Material in a Case of Acute Selenium Compound Poisoning

“…Determination of selenium in body fluids and tissues is usually carried out by molecular fluorescence spectrometry, that is, spectrofluorimetry (SF; [13–15]), atomic absorption spectrometry using either hydride generation or direct electrothermal atomization (HG‐AAS or ET‐AAS [8,15–18]), atomic fluorescence spectrometry with hydride generation technique (HG‐AFS; [19–24]), gas chromatography‐mass spectrometry (GC‐MS [10]), neutron activation analysis (NAA; [25]), and other methods (18). The modern method of inductively coupled plasma‐mass spectrometry (ICP‐MS; [26–28]) has some advantages over rival techniques, including low detection limits and speed of analysis; however, not all determinations are straightforward, in particular, the determination of selenium in serum—the sensitivity with conventional ICP‐MS is generally poor because only 30% ionization is achieved with an argon plasma and that there are relatively high spectroscopic interferences caused by the formation of argon polyatomic species (26). Moreover, NAA and ICP‐MS methods are not readily accessible by many laboratories (at least in Poland) because their running costs are very high.…”