The measurement of trace elements in human nails and nail clippings using portable X‐ray fluorescence: A review

Portable x-ray fluorescence for the analysis of chromium in nail and nail clippings

In this work instrumental neutron activation analysis was applied todetermine trace elements in nail clippings and to make a comparison betweenthe results obtained from samples from healthy children and those with cysticfibrosis (CF) disease. The findings indicated that fingernails from the CFgroup present higher concentrations of Cl, Cr, K and Na than those found inthe control group. On the other hand, the lowest concentrations for Cr werefound in the CF group. For the Al, As, Co, Fe, Mg, Mn, Se and Zn elementsthere were no differences between the results obtained for the CF and controlgroups. The quality control of the results was evaluated by analysing NIST1577b Bovine Liver and NIST 1566a Oyster Tissue standard reference materials.

Abstract. Kollberg, H. and Landström, O. (Department of Paediatrics, University Hospital, Uppsala and AB Atomenergi, Studsvik, Sweden). A methodological study of the diagnosis of cystic fibrosis by instrumental neutron activation analysis of sodium in nail clippings. Acta Paediatr Scand, 63: 405, 1974.–Instrumental neutron activation analysis (INAA) of nail clippings was used in the development of a diagnostic method for cystic fibrosis (CF). From CF patients and controls more than three years old, nail clippings were sampled for tests of different errors. As a result of this study a precise collection routine was outlined. Sodium is easily washed out from nail clippings. The risk of sodium contamination of the nails seems to be small. The sodium distribution in the nail is inhomogeneous, and the sodium content varies also from nail to nail in the same person. There is good evidence that the increased sodium in the nails of CF patients comes from the sweat. There seems to be a basic “intrinsic” sodium level, which is about the same in the nails of CF patients as in controls. The precision and accuracy of INAA for determining sodium in nails is considered satisfactory. It is concluded that INAA of the sodium concentration in nail clippings is a suitable method as an aid in the diagnosis of CF if a precise collection routine is used.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Abstract. Kollberg, H. and Ekbohm, G. (Department of Paediatrics, University Hospital, Uppsala, Sweden and Department of Statistics, University of Uppsala, Sweden). A clinical study of the diagnosis of cystic fibrosis by instrumental neutron activation analysis in nail clippings. Acta Paediatr Scand, 63: 411, 1974.–This article reports on the possibility of using instrumental neutron activation analysis (INAA) of sodium in nail clippings for diagnosing cystic fibrosis (CF) in children and adults, for detecting heterozygotes and for screening in the neonatal period. Nail clippings from 1322 newborns, 22 CF patients (two of them newborns), 52 healthy controls and 22 heterozygotes were analyzed. The discrimination between CF patients and controls was found to be precise for individuals above one year of age and INAA of nail clippings should be accepted as a diagnostic test for CF after this age. Heterozygotes could not be detected by the method. During the first five days of life there is a big overlap between the values from normal newborns and those of CF children, which makes the method invaluable for early screening for CF.

Trace elements play a significant role in biological processes. The aim of this study was to evaluate the trace elements of interest in kidney disease in commonly consumed greenhouse vegetables in Isfahan, Iran. Six kinds of greenhouse vegetables namely; Raphanus sativus (Radish), Cucumis sativus (Cucamber), Solanum lycopersicum (Tomato), green Capsicum annuum (Green bell pepper), yellow Capsicum annuum (Yellow bell pepper) and red Capsicum annuum (Red bell pepper) were collected from Isfahan greenhouses, between December 2012 to March 2013. The vegetables were analyzed in order to determine the concentrations of trace elements and trace minerals using instrumental neutron activation analysis (INAA). The results of INAA showed that, the concentrations of Fe (Iron), Mn (Manganese) and Zn (Zinc) were varied from <10-50.0 mgkg-1, 6.8-15.0 mgkg-1 and 10.0-23.0 mgkg-1, respectively. The elemental concentration of Fe, Mn and Zn in all of the samples were less than the defined tolerable Upper Intake Level (UIL). The results of this study revealed that, considering the measured trace elements and mineral content levels, Isfahan greenhouse vegetables do not impose any serious health harmful effects for individuals in the studied area due to their meal consumptions.

A calibration method was developed to assess elemental concentrations in nail clippings, using a portable X‐ray fluorescence (XRF) device. Specifically, manganese and zinc were investigated in this study. Two sets of phantom nail clipping samples were prepared, one set containing manganese and one set containing zinc. In both sets, elemental concentrations in the phantom clippings were varied from 10 to 50 µg/g, in increments of 10 µg/g. Additionally, for each concentration, five distinct masses of sample were prepared ranging from 20 to 100 mg, in increments of 20 mg. XRF spectrometry was performed with the various samples using a portable X‐ray tube and detector system.Kα characteristic X‐rays were detected for both manganese and zinc. Intensities of detection were plotted against added concentration, resulting in linear relationships for both manganese and zinc. The slopes of these calibration lines were then examined as a function of sample mass. An empirical function was fit to the slope–mass relationship and compared with those obtained previously from other elements. By using this XRF calibration approach, it is possible to estimate elemental concentrations in human nail clippings for a variety of elements of medical interest. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Arsenic (As) distribution in nail clippings from three healthy human subjects was investigated using the microbeam experimental setup of the hard x-ray micro-analysis (HXMA) beamline from the Canadian Light Source (CLS) synchrotron. A pair of toenail and fingernail clippings was collected from each of three subjects (one contributed two fingernail clippings). The fingernail and toenail clippings were embedded in polyester resin and cut in cross-sectional slices with an average thickness of 270 µm. Nine nail clipping cross sections were analyzed from the three subjects. The same method was used to produce five cross sections of nail phantom clippings with concentrations of As ranging from 0 to 20 µg g−1, in increments of 5 µg g−1. These samples were used to produce a calibration line for the As Kα peak. The energy of the x-ray beam was set at 13 keV for optimal excitation of As and the beam size was 28 × 10 µm2. Each sample was analyzed using a point-by-point scanning technique in a 45° beam-sample and 90° beam-detector geometry. The dwelling time was set at 30 s for the human nail clippings and 20 s for the nail phantom clippings, using a step size of 50 µm in both the horizontal and vertical directions for all samples. As concentration for each point was calculated based on the calibration line parameters and the fitted amplitude of the observed As Kα peak. As concentration maps were produced for each nail clipping cross section. The maps show that small regions (<0.1 mm2) with higher As concentrations (>1 µg g−1) are located predominantly in the ventral and dorsal layers of the nail. The results are in agreement with findings reported in a recent study and can be linked to nail histology and keratin structure.

Anabolic steroids are synthetic derivatives of testosterone, and their abuse can have numerous health consequences. Identification of this group of drugs has found applications in forensic toxicology, clinical situations, psychiatric disorders, and of course, anti-doping violations. Although anabolic steroids are generally tested in urine and very occasionally in head hair, collectors can face the lack of standard specimens, and therefore, nail clippings can be the unique alternative choice. Although there is no possibility to perform segmental analyses using nail clippings, the window of drug detection is generally much longer in nail when compared to head hair (particularly in male subjects), that is, 3-8months and 4-12months for finger and toenail clippings, respectively. A new method was developed, including nail pulverization in a ball mill, sonication for 90min in methanol, and a combination of liquid-liquid and solid-phase extractions, followed by gas and liquid chromatography coupled to tandem mass spectrometry. To document the application of steroid testing in nail clippings, the authors present 6 authentic cases of abuse, involving stanozolol (7 and 24pg/mg), nandrolone (6pg/mg), trenbolone (26, 67, 81, and 89pg/mg), drostanolone (8 and 11pg/mg), and testosterone enanthate (14pg/mg). Given concentrations were always in the low pg/mg range, the use of tandem mass spectrometry appears as a prerequisite.

Background:This study aimed to investigate the potential health concerns of trace elements and mineral content of commonly consumed greenhouse vegetables in Isfahan, Iran.Materials and Methods:Six kinds of greenhouse vegetables namely; Raphanus sativus (Radish), Cucumis sativus (Cucumber), Solanum lycopersicum (Tomato), green Capsicum annuum (Green bell pepper), yellow C. annuum (Yellow bell pepper), and red C. annuum (Red bell pepper) were collected from Isfahan greenhouses, between December 2012 and March 2013. The vegetables were analyzed in order to determine the concentrations of trace elements and trace minerals using instrumental neutron activation analysis (INAA).Results:The results of INAA showed that the concentrations of aluminum, bromine, cobalt, rubidium and strontium of these vegetables were varied from 7.2 to 28.4 mg/kg, 0.6–11.7 mg/kg, 0.1–0.5 mg/kg, 4.2–8.4 mg/kg, and 12.0–141.0 mg/kg, respectively. The trace mineral concentrations of As, Cr, Cs, Sc, Th, and U in all of the samples were less than the defined tolerable upper intake level.Conclusion:The results of this study revealed that considering the measured trace elements and mineral content levels, Isfahan greenhouse vegetables do not impose any serious health harmful effects for individuals in the studied area due to their meal consumptions.

The present work investigates the uptake of selected trace elements (Cu, Sb, As, Pb, Cd, Zn, Cr, Mn, Ni, V, and Co) from soil and their accumulation in the biomass samples (leaves and flowers) of three selected native plants (namely Oenothera picensis, OP; Sphaeralcea velutina, SV; and Argemone subfusiformis, AS) around an industrial area (Puchuncaví-Ventanas) located in the Puchuncaví valley, in the central region of Chile. Primary emission sources in the area come from a copper refinery, coal-fired power plants, and a set of 14 other different industrial facilities. Trace element measurements in the native plants of this area and the ability to transfer of these pollutants from soil to plants (transfer factor) have been assessed in order to identify the potential use of these plant species for phytoremediation. Preliminary results showed a high concentration of trace elements in the OP, SV, and AS samples. The concentration of these elements in the plants was found to be inversely correlated to the distance of the primary emission sources. Moreover, the high concentrations of trace elements such as Cu, As, Cr and V, upon the toxic limits in the native plant species, suggest the need for continuous monitoring of the region. The OP species was identified as the plant with the highest capacity for trace elements accumulation, which also showed higher accumulation potential in whole aerial parts than in leaves. Transfer factor values suggested that these native plants had phytoremediation potential for the elements Cu, Pb, As, Ni, and Cr. This study provides preliminary baseline information on the trace element compositions of important native plants and soil in the Puchuncaví-Ventanas area for phytoremediation purposes.

A calibration method for proposed x-ray fluorescence (XRF) measurements of arsenic and selenium in nail clippings is demonstrated. Phantom nail clippings were produced from a whole nail phantom (0.7 mm thickness, 25 × 25 mm2 area) and contained equal concentrations of arsenic and selenium ranging from 0 to 20 µg g−1 in increments of 5 µg g−1. The phantom nail clippings were then grouped in samples of five different masses: 20, 40, 60, 80 and 100 mg for each concentration. Experimental x-ray spectra were acquired for each of the sample masses using a portable x-ray tube and a detector unit. Calibration lines (XRF signal in a number of counts versus stoichiometric elemental concentration) were produced for each of the two elements. A semi-empirical relationship between the mass of the nail phantoms (m) and the slope of the calibration line (s) was determined separately for arsenic and selenium. Using this calibration method, one can estimate elemental concentrations and their uncertainties from the XRF spectra of human nail clippings.

The paper presents concentrations of trace elements in blood of homebred animals (cows and sheep) from Southern Serbia (Bujanovac) and the contents of natural and anthropogenic radionuclides and some heavy metals in feed. The region of Southern Serbia was exposed to contamination by depleted uranium ammunition during NATO attacks in 1999 and therefore, is of great concern to environmental pollution and human and animal health. Conventional instrumental and epithermal neutron activation analyses are used to measure trace elements in cow and sheep blood samples collected randomly at six locations in the region of Bujanovac (village of Borovac) in the spring of 2005. Samples of feed (grass and crops: corn, wheat and oats), collected on the same locations (households), are analysed for the contents of radionuclides on an HPGe detector (Ortec, relative efficiency 23%) by standard gamma spectrometry. The content of Hg, Pb and Cd in feed is determined by standard atomic absorption spectrometry on the VarianSpectra220/ThermoSolar GFS97 spectrometer. Concentrations of 29 elements (Na, Al (P), Cl, K, Sc, Cr, Mn, Ni, Fe, Co, Zn, Se, As, Br, Sr, Rb, Sb, In, I, Ba, Cs, La, Nd, Eu, Sm, Tb, Hf, Ta and Th) are determined in blood of the examined animals. In feeds, natural (40)K is found in all of the samples, cosmogenic (7)Be and fission product (137)Cs are detected only in the grass samples, while heavy metals Hg, Cd and Pb are found in the range of 0.01-0.02, 0.84-1.15 and 0.74-7.34 mg/kg, respectively. Calculated soil-to-blood transfer factors are in a wide range of 8 x 10(-6) to 64, as a result of varying significance of the elements in animal metabolism and feeding habits. The results of trace elements' concentrations in animal blood are in good agreement with available data for K, Ni, Zn, Se and Rb. Higher Br concentrations in animal blood are most probably caused by large biomass burning events during blood sampling. Very low concentration of Fe in cows and sheep confirms the results of previous biochemical studies on animal anaemia in the region. High concentration of As correlates with geochemical peculiarities of the Balkans and is also likely influenced by the use of pesticides in the agricultural production. For some of the elements (La, Nd, Eu, Sm, Tb, Sb, Hf, Ta, Th, In, Ba, Sr, Sc and Cs), there are few or no literature data. Therefore, some of the presented data are significant not only for the country and the region, but on a wider scale. Activities of natural radionuclides in feeds are within the average values reported for the region, while the activities of (210)Pb and (235/238)U are below the limit of detection. This is in accordance with previous investigations showing no widespread contamination by depleted uranium in the area. Contents of Hg and Pb in feeds are below the nationally permissible levels, unlike the content of Cd which exceeds it, probably caused by the use of phosphate fertilisers and fossil fuel combustion in the area. In general, the concentrations of trace elements in blood of homebred cows and sheep are in good agreement with reference materials, available literature data and the results of previous studies in the area. The exceptions are Fe, As and Br. The contents of natural and anthropogenic radionuclides in feeds are within the expected levels, and there are no signs of contamination by depleted uranium or other fission products. Apart from Cd, there are no signs of pollution by heavy metals in feeds. The highly sensitive method of instrumental neutron activation analysis provides data on the concentration of some elements in animal blood not previously reported for the region and elsewhere. The presented study is a part of the long term ongoing project on the health risk assessment on animals and humans in the region. The collected data is intended to provide a base for the animal and human risk assessment as well as an estimate of the general pollution status of the environment in the region. Since some of the investigated elements are classified as important trace elements for livestock, the results could also be used to balance and improve the animal diet and thus, improve the growth and reproduction rate.

The term "trichothiodystrophy" (TTD) covers several autosomal recessive diseases whose diagnostic hallmark is short, brittle hair low in sulfur and cystine because of impaired synthesis of high-sulfur matrix protein. Clinical symptoms associated with TTD represent a variable range of abnormalities in organs derived from ectoderm and neuroectoderm. Important laboratory tests of the hair for the diagnosis of TTD comprise polarizing microscopy ("tiger-tail" pattern), electron microscopy, and amino acids analysis of hydrolyzed hair with a special focus on cystine. However, only very few institutions determine the amino acid composition of human hair and nail clippings, which requires special sample preparation including hydrolysis. If no special precautions are taken, quantification of cysteine and cystine becomes inaccurate because of decomposition of these residues during hydrolysis. We therefore performed the sample work-up with azide-dependent oxidation which we have for the first time adapted for analysis of hair and nail clippings. With our control and parent data resembling published data on hair and nail samples, we obtained a decreased proportion of cysteine (half cystine, determined as cysteic acid) in materials obtained from a boy with TTD. Clearly, the method for the quantification of cysteine following sodium azide-dependent oxidation is a suitable and rather convenient approach to the quantification of cyst(e)ine and other amino acids in hair and nail proteins, and is a valuable contribution to the diagnosis of TTD.

Clomiphene or clomifene is a selective estrogen receptor modulator (SERM), used to treat female fertility in case of ovulatory dysfunction. In sport, clomiphene is prohibited at all times for use by athletes and is listed in the section S4.2 (hormone and metabolic modulators) by the World Anti-Doping Agency (WADA). Indeed, clomiphene can indirectly increase testosterone levels in the body and can mitigate some side effects of synthetic steroid abuse. Despite its prescription to millions of subjects, its detection in human hair or nail clippings has never been reported. The aim of this study was to develop a specific method to identify clomiphene in hair and nail clippings by LC-MS-MS. The procedure was then applied in a case of challenged doping results. The method involves sonication/incubation for 1 hour of 30 mg of pulverized material in 1 mL of methanol in presence of 2 ng diazepam-d5 used as internal standard. The chromatographic separation was performed using a HSS C18 column with a 15 min gradient elution. After spiking blank hair and nail with the corresponding amounts of clomiphene, linearity was verified from 1 to 500 pg/mg (r² = 0.9994 and 0.9995 for hair and nail, respectively). The limit of detection was estimated at 0.3 pg/mg for both matrices. No interference was noted from endogenous compounds, particularly steroids. Clomiphene was identified at 85 and 20 pg/mg in the pubic hair and the fingernail clippings, respectively, of a male athlete challenging an adverse analytical finding.