Differences in trace-element concentrations in hair between males and females

Hair clippings (from the head) from over a hundred persons in and around Orange County of California were analysed for mercury, gold, zinc, and copper by instrumental neutron activation analysis. The results of the study show significant differences in the trace-element distributions between males and females. For mercury, the mode of the distribution occurs at about 1 to 1,5 ppm for males and 4 to 6 ppm for females. A significant difference between the male and female distribution curves was also found for gold, and a less significant one for zinc and copper. This study indicates the possibility that the high levels of mercury and gold in the hair of females are more likely due to external contamination, because of the more frequent and intense exposure of their hair to cosmetics. Moreover, as females usually have longer hair, their hair strands are exposed to such treatment over a longer period of time. Hair being a good ion-exchange material, trace elements are absorbed easily during the process of washing and setting of hair, and accumulation of these over a long period may cause a very high concentration of these elements. The variability of trace-element concentration as a result of external contamination, and the sometimes marked variation along the length of the hair, pose a serious problem in forensic work. Identification criteria should provide for these variations, especially in the case of mercury and gold. This work also indicates that if the evidence hair from the scene of a crime does not contain the root end, its value as an evidence specimen is considerably reduced.     

Time-of-flight secondary ion mass spectrometry analysis of hair from archaeological remains

Hair from four individuals excavated from burial sites in Pacatnamu, Peru from the Moche (450-800 AD) and Lambayeque (900-1100 AD) periods was sectioned longitudinally and analysed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). An attempt was made to distinguish biogenic and diagenetic contributions to the elemental concentrations in the hair samples. Significant contamination was observed to have penetrated the hair samples from the burial environment. Results from the analyses indicate that the burial environment plays an important role in the postmortem variation in elemental content of hair samples. Various elements demonstrated an ability to permeate through the hair matrix over time. In addition, NaCl and what are believed to be aluminosilicates and mineral sulphates, were observed to have accumulated on the surface of the samples. Degradation of the samples was also suspected due to the presence of molecular fragments, possibly resulting from oxidation of the keratin proteins. The results should assist in the identification of reliable elemental signals in the analysis of ancient hair samples and promote caution when considering elements that are abundant in the burial environment.     

Mass imaging of ketamine in a single scalp hair by MALDI-FTMS

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) coupled with mass spectrometry imaging (MSI) is a rapidly emerging technology that produces distribution maps of small pharmaceutical molecules in situ in tissue sections. Segmental hair analysis provides useful information regarding the state and history of drug use. A preliminary MALDI-Fourier transform ion cyclotron resonance (FTICR)-MSI method was developed for direct identification and imaging of ketamine in hair samples. After decontamination, the scalp hair samples from ketamine users were scraped gently and were fixed onto a stainless steel MALDI plate using double-sided adhesive tape. A Bruker 9.4 T solariX FTICR mass spectrometer with continuous accumulation of selected ions function was used in the positive ion mode. Four single hairs from the same drug abuser were analyzed. Three of four single hairs demonstrated ketamine spatial distribution, while only traces of ketamine were identified in the other one. The platform could provide detection power of ketamine down to the 7.7 ng/mg level in hair. MALDI-FTICR-MSI demonstrated the drug distribution over the whole hair length with higher spatial resolution compared with the traditional LC-MS/MS method after scissor cutting. Greater caution is needed in the interpretation of a single hair result because of the considerable variations in the growth rate and sample collection.     

用多变量统计分析方法辨识肺癌患者分类中的关键元素(英文)

用逐步判别、主成分分析和聚类方法研究了根据血清和毛发样品中元素含量对正常人和肺癌患者分类中的关键元素．用主成分分析的结果表明,在肺癌患者与正常人的分类中,血清中的Ｃａ,Ｃｒ,Ｃｕ,Ｐ和Ｚｎ是关键元素,而毛发中的Ａｌ,Ｂ,Ｃｒ,Ｐ和Ｓｒ是关键元素．对于正常人和癌症患者元素之间的欧氏距离不同     

Forensic and environmental aspects of neutron activation analysis of single human hairs

A new analytical procedure consisting of special washing step, irradiation in a thermal neutron flux of ∼10¹⁴n·cm⁻²·sec⁻¹, and Ge(Li) spectrometry enabled to determine as many as 14 elements in a 3 cm segment of a single human hair by neutron activation analysis (NAA). The criminalistic aspects of hair analysis were studied using a new statistical criterion for elimination/identification and an appropriate computer program was constructed. Hair dimensions as measured microscopically were used as additional individualizing attributes. It was shown that despite the difficulties orginating from a relatively large intrinsic variation of the trace element concentration over one head, elimination of most or nearly all of the “suspects” could be achieved in simulated cases. Distincly elevated level of Au as well as Cu and Ag were found in hair of some groups of persons working under specific conditions thus confirming the importance of the environmental factor related to some kinds of occupation.     

XRF and TXRF techniques for multi-element determination of trace elements in whole blood and human hair samples

XRF and TXRF were established as useful techniques for multi-element analysis of whole blood and human head hair samples. Direct-XRF with different collimation units and different X-ray excitation modes was successfully used for the determination of S, P, K, Ca, Fe, and Br elements in blood samples and K, Ca, Mn, Fe elements in human hair samples. Direct analysis by TXRF was used for the determination of Rb and Sr in digested blood and human hair samples, respectively, while, the co-precipitation method using APDC for TXRF analysis was used for the determination of Ni, Cu, Zn, and Pb elements in both matrices. As a result, the improved XRF and TXRF methods were applied for multi-element determination of elements in whole blood and human hair samples in non-occupational exposed population living in Damascus city. The mean concentrations of analyzed elements in both matrices were on the reported range values for non-occupational population in other countries.     

Exploring lead exposure in ancient Chilean mummies using a single strand of hair by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

Lead exposure has received increased attention over the past few decades since it has been shown to have adverse effects on physical and intellectual development in humans. The use of biological tissues such as blood, teeth, hair, and bone for assessment of lead exposure has been previously demonstrated. While analysis of blood for trace metals provides information concerning recent exposure, hair offers insight into a period of several months, and is preferable since it is non-invasively collected and easily stored. The present study analyzed total of 49 ancient hair samples for lead (Pb_H) using LA-ICP-MS. Samples belonged to an ancient fisher hunter–gatherer culture called the “Chinchorro,” and who occupied regions of the Atacama Desert on the northern coast of Chile from approximately 5000–1500 B.C. and practiced the first-known form of artificial mummification. Several samples from a post-Chinchorro agricultural community (n = 12) ca. 1000–1400 A.D. were also analyzed. A suite of hair standards was developed using contemporary hair from the same region and was subsequently used to make linear calibration functions for lead determination in single strands of hair using LA-ICP-MS. Three linear scans ranged from 500 to 1000 μm were performed for each sample and signal intensities were normalized over ¹³C. The distribution of lead in the central medulla in a 100 μm cross-section scan of hair strand demonstrated minimal exogenous contamination. Hair lead (Pb_H) concentrations ranged between 2.2 μg/g and 12.8 μg/g could be accurately quantified with these standards. Twenty one out of 49 samples (43%) showed Pb_H concentrations higher than the average value of 5 μg/g for unexposed individuals (range 1.1–228.0 μg/g). Median hair lead concentrations by burial sites and are shown in order of decreasing concentration: Morro (13.8 μg/g) > Iquique (6.6 μg/g) > Azapa (4.5 μg/g) > Yungay (4.1 μg/g) > Camarones (2.7 μg/g). Most of the burial sites showed Pb_H concentrations greater than the normal value for unexposed individuals and outliers heavily influenced average concentrations. The results suggest that the Chinchorro and later agro-pastoral populations were not widely exposed to naturally elevated lead.     

Precise Zn isotopic ratio measurements of human red blood cell and hair samples by multiple collector-ICP-mass spectrometry.

Precise 66Zn/64Zn and 68Zn/64Zn isotopic ratios of biochemical samples have been measured using multiple collector-ICP-mass spectrometry (MC-ICPMS). In order to eliminate the mass spectrometric interferences on Zn isotopes (e.g., 64Ni+ and 136Ba2+), we chemically purified the analyte using an ion chromatographic technique. The resulting precisions of the 66Zn/64Zn and 68Zn/64Zn ratio measurements were 0.05/1000 and 0.10/1000 (2SD), respectively, which were enough to detect the isotopic variation of Zn in nature. Red blood cell (RBC) samples were collected from five volunteers (four males and one female), including a series of 12 RBC samples from one person through monthly-based sampling over a year. These were analyzed to test possible seasonal changes and variations in 66Zn/64Zn and 68Zn/64Zn ratios among the individuals. The 66Zn/64Zn and 68Zn/64Zn ratios for a series of 12 RBC samples collected over a year were 0.43/1000 and 0.83/1000 higher than the values of highly purified Zn metal (JMC Zn), and no seasonal change could be found. The 66Zn/64Zn and 68Zn/64Zn ratios for RBC samples collected from five volunteers did not vary significantly. In order to investigate Zn isotopic heterogeneity in a human body, Zn isotopic ratios of a hair sample collected from one of the volunteers was also analyzed. The 66Zn/64Zn and 68Zn/64Zn ratios for the hair sample were 0.59/1000 and 1.14/1000 lower than the mean value of RBC samples. This result demonstrates that detectable isotopic fractionation occurs in the human body. The data obtained here suggest that the isotopic ratios of trace metals could provide new information about transportation of metal elements in vivo.     

Short term and long term variations of Ca-concentration in beard

The Ca-concentration has been measured in daily shaven beard samples over a seven-year period. The Ca-concentration range in beard of single individuals is the same as that in the head hair of different groups. Inviduals belonging to the group with low Ca-level (Ca<700 ppm) in hair (endangered group from ischaemic heart diseases) may increase the Ca-level in their hair and get into the group with high Ca-level (Ca>700 ppm; defended group).     

A rapid solid sampling method for determination of nickel and copper along human hair by ETAAS

A procedure for copper and nickel determination in scalp hair by solid sampling electrothermal atomic absorption spectrometric method was described. The hair samples (0.02 to 0.4 mg) were inserted directly on the platforms of solid sampling autosampler. The effects of pyrolysis temperature, atomization temperature, the amount of sample as well as addition of a modifier (Pd/Mg) and/or auxiliary digesting agents (hydrogen peroxide and nitric acid) and/or a surfactant (Triton X-100) on the determination of copper and nickel by solid sampling atomic absorption spectrometry were investigated. After optimization of parameters, the average recoveries of copper in two different certified reference hair samples were 105.7 and 97.6%. The recoveries of nickel in the both certified reference hair samples were in 95.2 and 96.4%. The limits of detection (3σ, N = 10) for copper and nickel were 22 ng/g and 35 ng/g, respectively. Heterogenous distribution of analyte in microscale for segmental analysis could be determined which is important to know that analyte quantity and time of poisoning of a person was exposed. For this purpose, 0.5 cm of pieces were cut along one or a few close strands and analyzed by solid sampling. This process could not be performed by wet-digestion method because 50 mg of sample is needed each time. Finally, the method was applied for the determination of copper and nickel concentrations in the hairs of different persons.     

人工神经网络方法用于肺癌的辅助诊断

根据人发和血清中微量元素的含量,将人工神经网络(ANN)用于正常人与癌症患者的分类预测.用独立预测样本作了检验,表明该方法可作为肺癌诊断的一种辅助手段.讨论了当预测样本中有元素缺损时ANN的分类预测情况,并研究了人发和血清样品中的元素对分类预测的影响.     

Radiochemical analysis of toxic elements in biological materials

A radiochemical method for simultaneous determination of toxic elements (Hg, Cd and Sb) in biological materials has been developed. The procedure involves the irradiation of samples with thermal neutrons and quantitative one-step separation in 0.1M 4-(5-nonyl)pyridine/benzene from 2.0M hydrochloric acid followed by gamma-ray spectrometry. The procedure is applied for the analysis and to the studies of distribution of these elements in IAEA-RMs, human serum and hair samples. Results obtained are found to be in good agreement with those reported in the literature.     

Determination of chromium,manganese, lead and cadmium in biological samples including hair using direct electrothermal atomic absorption spectrometry

Direct analysis of solid samples employing a laboratory assembled electrothermal atomic absorption spectrometer is demonstrated to be a feasible approach for determination of trace elements in plant tissue and hair samples for special applications in plant physiology and biomedical research. As an example, the kinetics of Cr uptake by cabbage and its distribution have been measured as a function of chromium speciation in the nutrient solution. Further, longitudinal concentration gradients of Cr, Pb and Cd have been measured in hair of various population groups exposed to different levels of these elements in ambient and/or occupational environments. The techniques are validated for the determination of these trace elements by neutron activation analysis, dissolution atomic absorption spectrometry and by analysis of certified reference materials. Slurry sample introduction is found appropriate for routine trace element determination and in homogeneity testing. Direct sample introduction is indispensable in the analysis of very small (< 1 mg) tissue biopsy samples in the determination of trace element distributions.     

Hair as a bio-indicator: Limitations and complications in the interpretation of results

As part of a larger occupational exposure study in which the concentrations of 18 elements were measured in head hair and toenail collected from steel plant workers, a number of factors associated with interpreting the data obtained were examined. In this paper, some of the limitations and complications associated with hair and nail analysis that were thereby recognised are discussed. Data obtained from the occupational study demonstrated the potential for misinterpreting hair or nail analysis data either through describing results averaged over a group by arithmetic instead of geometric means or through not accounting for the age range of subjects in groups to be compared. Examples that arose from the study indicated that differences between hair from the same subjects grown at different times can both complicate and assist in interpreting hair analysis results. In an investigation into the addition and removal of metallic powders, it was found that both hair and nail can directly incorporate elements through contact with dust.     

Multielement neutron activation analysis of human scalp hair a local population survey in the Tokyo metropolitan area

Applying instrumental neutron activation analysis, multielement analysis of human hair was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo metropolitan area. 202 hair samples were collected from the inhabitants classified by sex and five age groups. Using several combinations of irradiation time, cooling time and counting time, forty elements were quantitatively analyzed. The method of analysis for data including samples under detection limit is discussed, assuming that the frequanecy distribution of trace element contents in hair is log-normal.     

Tandem mass spectrometric analysis of novel diquaternary ammonium gemini surfactants and their bromide adducts in electrospray-positive ion mode ionization

Gemini surfactants are cationic lipids which are utilized for both in vitro and in vivo gene delivery. Structurally, they are comprised of two hydrophobic tail regions with polar head termini that are attached to one another through a spacer region. Structural elucidation and characterization of 29 novel diquaternary ammonium gemini surfactant molecules were achieved using a quadrupole time-of-flight mass spectrometer (QqToF-MS) and a quadrupole-hexapole-quadrupole mass spectrometer (QhQ-MS). The tested compounds were categorized into four distinct structural families based upon the composition of the spacer region. Single stage (MS), tandem stage (MS/MS) and quasimulti-stage (quasi MS(3)) mass spectrometric analysis allowed for confirmation of each gemini surfactant's molecular composition and structure through the identification of common and unique product ions. Identification of similarities in the gemini surfactants' fragmentation behaviour resulted in the production of a universal fragmentation pathway that can assist in the future MS/MS analysis of novel quaternary ammonium gemini surfactants, with unique product ions being indicative of specific structural elements. Furthermore, evidence for the association of agemini surfactant with bromine counter ion was confirmed during MS analysis of tested gemini surfactants regardless of their chemical composition; previously, evidence for bromine and gemini surfactant association was only observed with compounds bearing short alkyl spacer regions. MS/MS analysis of the bromine adducts was also confirmatory to the molecular structure.Understanding the ionization and fragmentation behaviour of gemini surfactants, including bromine adducts, will allow for future qualitative and quantitative identification of these novel drug delivery agents within biological samples.     

Radioactivation analysis of hair a means of biological monitoring of the environment

With the aim of indicating environmental pollution effects by heavy metals on humans using hair, nondestructive activation analysis was applied to 382 normal Japanese hair samples (background level). Elemental contents of hair could be determined for Ag, Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, I, K, La, Mg, Mn, Na, S, Sb, Sc, Se, Sm, Ti, V and Zn. As these elements in hair have wide concentration ranges, the differences in concentrations distribution between groups (sex, age, permanent treatment and regional difference) are discussed. A method for hair sampling is presented.     

Aktivierungsanalyse von Umwelt-Metallen in Menschlichem Kopfhaar

During the last few years human scalp hair, a horny fibrous derivative of the skin, became well recognized as an invaluable tissue for monitoring human environmental exposure. The sequential accumulation of a number of elements in particular (growth rate of hair strands ca 0.3 mm/day), the fact that the concentrations of trace elements in hair are at least an order of magnitude greater than in the body fluids and other accessible tissues, as well as the simple obtainment and the easy preparation of the specimen, reveal the advantages of this test material. Therefore systematic analyses of concentrations and distribution of arsenic, antimony, cadmium, mercury, bromium and zinc in hair samples obtained from population groups of four Austrian provinces (Bundesländer) were accomplished by INAA. The selection of those regions are based on the distinct economic structure caused by the geographical location as well as the heterogenous geological structure of the country.     

Trace elements in head hair of hemodialysis patients

Instrumental neutron activation analysis /INAA/ was applied to measure trace elements in head hair of 19 patients with impaired renal function /14 males and 5 females/ and of 40 normal individuals /20 males and 20 females/. It was the aim to use head hair as a possible indicator of total body trace elements status and to investigate whether significant changes occur as a result of chronic hemodialysis. The elemental concentrations of 20 elements /i.e. Na, Mg, Al, Cl, K, Ca, V, Mn, Fe, Co, Cu, Zn, As, Se, Br, Ag, Cd, Sb, I and Au/ are presented and compared with published data. The present study revealed that the hair of the dialysis patients contained about ten times more iodine than that of the control group. No significant differences were observed for the other elements measured, except for sodium and antimony.     

Neutron activation analysis of neonate and maternal hair sampled in areas with different levels of pollution

Instrumental neutron activation analysis has been performed on human head hair of newborns and mothers sampled in two areas with a different level of environmental exposure. The group of neonates from the exposed area (polluted by thermal power plants burning brown coal and by chemical industry) has exhibited higher levels of several trace elements in hair, e.g. Se, Zn, Hg and Sb in comparison with the control group. Moreover, the mean concentrations of Se, Hg, Zn and Br in neonate hair have been found to be higher than in mothers hair. Although the study revealed statistically significant differences in the composition of neonate hair sampled in areas with different levels of environmental exposure, the differences are relatively small. Only a thorough long-term study both with environmental and medical observations can prove a direct connection of the elevated levels of some trace elements in neonate hair with the higher frequency of mental diseases of children living in the exposed area.