1. Introduction
Selenium is an essential trace element of several major metabolic
pathways, including thyroid hormone metabolism, antioxidant
defence systems and immune functions [1–3]. Thus, there is a strong
need for analytical techniques to be able to perform the accurate
analysis of selenium in different biological matrices and at low
concentration levels. In addition, information about the distribution of
other important elements like sulphur and transition metals is
required. One analytical challenge in biological and medical research
is the extremely small available sample amount, e.g. organ homogenates
from laboratory mice.
Due to the high importance of selenium, numerous approaches to
control the selenium content of food have been made [4]. In fact the
selenium concentration in staple food like wheat has an influence on
the sales price. This demands fast and easy analytical solutions for
selenium analysis that can also be applied under challenging
conditions e.g. close to wheat-processing sites.
The increasing knowledge about the importance of selenium for
human health has also led to a variety of selenium-containing dietary
supplements. Here the analytical task is the accurate determination of
selenium in samples with variable concentrations and matrices.
In the case of medical samples like human blood, there are several
established atomic spectroscopy methods for routine analysis. Typical
detection limits for selenium in whole blood samples are 0.7 μg/l for
electrothermal atomic absorption spectroscopy (ETAAS) and 0.05 μg/l for
flow injection analysis electrothermal atomic absorption spectroscopy
(FIA-ETAAS) [5]. For other analytical methods, detection limits are
reported to be in the range of 0.5 μg/l for hydride generation inductively
coupled atomic emission spectroscopy (ICP AES) [5] and 0.02 μmol/l for
blood analysis by means of inductively coupled plasma mass spectrometry
(ICP-MS) [6].
All these sophisticated methods demand qualified laboratory staff,
enhanced laboratory equipment and involve high operation costs.
Furthermore, the atomic spectroscopy methods have to a certain
extent limitations with regard to the required element range and the
available sample amount.
This paper deals with the possibilities and restrictions of the total
reflection X-ray fluorescence (TXRF) method for the analysis of
biological, medical and food samples as well as dietary supplements.
The general advantages of this analytical technique are that minute
sample amounts can be analysed without the need for complicated
sample preparation and external calibrations, that the matrix or memory
Spectrochimica Acta Part B 65 (2010) 859–863
☆ This paper was presented at the 13th Conference on Total reflection X-ray
Fluorescence Analysis and Related Methods (TXRF 2009), held in Gothenburg, Sweden,
15–19 June 2009.
⁎ Tel.: +49 30 67099061; fax: +49 30 67099030.
E-mail address: hagen.stosnach@bruker-axs.de.
0584-8547/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
1. Introduction
Selenium is an essential trace element of several major metabolic
pathways, including thyroid hormone metabolism, antioxidant
defence systems and immune functions [1–3]. Thus, there is a strong
need for analytical techniques to be able to perform the accurate
analysis of selenium in different biological matrices and at low
concentration levels. In addition, information about the distribution of
other important elements like sulphur and transition metals is
required. One analytical challenge in biological and medical research
is the extremely small available sample amount, e.g. organ homogenates
from laboratory mice.
Due to the high importance of selenium, numerous approaches to
control the selenium content of food have been made [4]. In fact the
selenium concentration in staple food like wheat has an influence on
the sales price. This demands fast and easy analytical solutions for
selenium analysis that can also be applied under challenging
conditions e.g. close to wheat-processing sites.
The increasing knowledge about the importance of selenium for
human health has also led to a variety of selenium-containing dietary
supplements. Here the analytical task is the accurate determination of
selenium in samples with variable concentrations and matrices.
In the case of medical samples like human blood, there are several
established atomic spectroscopy methods for routine analysis. Typical
detection limits for selenium in whole blood samples are 0.7 μg/l for
electrothermal atomic absorption spectroscopy (ETAAS) and 0.05 μg/l for
flow injection analysis electrothermal atomic absorption spectroscopy
(FIA-ETAAS) [5]. For other analytical methods, detection limits are
reported to be in the range of 0.5 μg/l for hydride generation inductively
coupled atomic emission spectroscopy (ICP AES) [5] and 0.02 μmol/l for
blood analysis by means of inductively coupled plasma mass spectrometry
(ICP-MS) [6].
All these sophisticated methods demand qualified laboratory staff,
enhanced laboratory equipment and involve high operation costs.
Furthermore, the atomic spectroscopy methods have to a certain
extent limitations with regard to the required element range and the
available sample amount.
This paper deals with the possibilities and restrictions of the total
reflection X-ray fluorescence (TXRF) method for the analysis of
biological, medical and food samples as well as dietary supplements.
The general advantages of this analytical technique are that minute
sample amounts can be analysed without the need for complicated
sample preparation and external calibrations, that the matrix or memory
Spectrochimica Acta Part B 65 (2010) 859–863
☆ This paper was presented at the 13th Conference on Total reflection X-ray
Fluorescence Analysis and Related Methods (TXRF 2009), held in Gothenburg, Sweden,
15–19 June 2009.
⁎ Tel.: +49 30 67099061; fax: +49 30 67099030.
E-mail address: hagen.stosnach@bruker-axs.de.
0584-8547/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
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