A simple method of X-ray fluorescence analysis in hair

Kubo, Hideo

doi:10.1088/0031-9155/26/5/006

Cited by 12 publications

(3 citation statements)

References 8 publications

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“…The corresponding value of Z eff for human hair reported by H. Kubo using the transmission method is equal to 8.2. 34 The variation of the Z eff observed among the studied nail samples could be related to the varying amino acid composition of the nail keratin. The Z eff of the various amino acids determined using Eq.…”

Section: Effective Atomic Number Of Human Nailsmentioning

confidence: 93%

Application of Conventional and Microbeam Synchrotron Radiation X-Ray Fluorescence and Absorption for the Characterization of Human Nails

Katsikini

Mavromati²,

Pinakidou³

et al. 2010

J. Nanosci. Nanotech.

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The synchrotron radiation based spectroscopies X-ray fluorescence and X-ray absorption fine structure are used to detect illness-related changes in the elemental distribution and bonding environment of metals in human nails. The effective atomic number of a collection of nails is determined using two methods, the X-ray transmittance and the scattering method, and is found equal to 7.5 +/- 0.5. X-ray fluorescence maps of the elemental distributions, recorded with a lateral resolution of 5 microm, reveal that S, Ca and Zn are distributed homogeneously while Fe tends to cluster. In the Fe-rich clusters, which have a diameter in the range 15-30 microm, the Fe concentration is 10 times higher than in the matrix. The Zn K edge X-ray Absorption Fine Structure spectra reveal that Zn, in the nails from healthy donors and patients suffering from lung diseases, is four-fold coordinated with N and S and the Zn-N and Zn-S distances are equal to 2.03 A and 2.25 A, respectively. Finally the signature of various bonds in the C-, O- and N- K near edge X-ray absorption fine structure spectra is discussed.

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Section: Effective Atomic Number Of Human Nailsmentioning

confidence: 93%

Application of Conventional and Microbeam Synchrotron Radiation X-Ray Fluorescence and Absorption for the Characterization of Human Nails

Katsikini

Mavromati²,

Pinakidou³

et al. 2010

J. Nanosci. Nanotech.

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“…2 . 0 t , central, Eqn ( 7 ) homogeneous, Eqn (4) via Eqn (6) and (7)] on the other. Tn all cases, the same mass per unit area was assumed.…”

Section: Macroscopic Effect In a Bundle Of Hairmentioning

confidence: 99%

Heterogeneity effects in direct x‐ray fluorescence analysis of hair

Török¹,

Dyck²,

Grieken³

1984

X-Ray Spectrometry

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The methodology of direct hair analysis by energy‐dispersive x‐ray fluorescence was studied. The effect on the XRF result of having a non‐homogeneous radial distribution of the analyte in a single hair strand and the macroscopic effects in a bundle of hairs were calculated to evaluate possible systematic errors. The detection limits were mapped as a function of the target thickness and surface fraction. It appeared that a 10 mg cm−2 sample thickness, i. e. a target with about four layers of hair strands, is recommended. The standard deviation of this simple direct analytical method is 6–19% for some important elements. Discrepancies with neutron activation analysis had a mean value of around 15%. About twelve elements can be determined simultaneously on a routine basis.

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“…In vivo X R F measurements in humans cover a range of elements from iron ( 2 = 26) to thorium ( 2 = 90) with corresponding characteristic x-ray photon energies varying from 6.4 to 93.3 keV (Christoffersson 1986). In uirro assays include human hair (Kubo 1981) and blood and tissue samples (Cesareo 1982). In these various applications, fluorescent x-rays have been induced by radiation from either radionuclide sources or x-ray tubes.…”

Section: Introductionmentioning

confidence: 99%

Temporal instabilities associated with a planar high purity germanium detector

Pugh

Owen²,

Evans

1990

Phys. Med. Biol.

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Experiments have been performed which show that a grooved planar high purity germanium semiconductor detector may give rise to time variant counting rates in energy regions below prominent spectral peaks. It is postulated that this effect is due to prolonged or incomplete charge collection in the vicinity of the bottom of the groove, and is caused by distortions in the applied electric field in this region. Such effects may lead to changes in the minimum detectable count rate in x-ray fluorescence measurements; these can be reduced by collimating incident photons on the central region of the detector but the resulting reduction in efficiency lowers the overall sensitivity.

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A simple method of X-ray fluorescence analysis in hair

Cited by 12 publications

References 8 publications

Application of Conventional and Microbeam Synchrotron Radiation X-Ray Fluorescence and Absorption for the Characterization of Human Nails

Application of Conventional and Microbeam Synchrotron Radiation X-Ray Fluorescence and Absorption for the Characterization of Human Nails

Heterogeneity effects in direct x‐ray fluorescence analysis of hair

Temporal instabilities associated with a planar high purity germanium detector

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