Sex determination of mummies through multi-elemental analysis of head hair using electrothermal vaporization coupled to inductively coupled plasma optical emission spectrometry

Sex determination of human remains is of great archaeological significance, as it provides a more complete picture of social and familial structures within ancient societies. Typically performed through examination of bones in the pelvic region, accurate sex determination can be exceedingly challenging in the absence of a sufficiently preserved skeleton. Here, a method for sex determination in living humans, involving measurement of magnesium, strontium, sulfur, and zinc in head hair along with multivariate statistics, was applied for the first time to hair collected from 500 year-old mummies originating from Peru. Hair samples were washed in doubly deionized water, dried, and ground prior to analysis via electrothermal vaporization coupled to inductively coupled plasma optical emission spectrometry; only 2 mg of hair is required for analysis. Point-by-point internal standardization was performed with Ar i 430.010 nm to compensate for sample loading effects on the plasma. Peak areas were integrated and mass corrected before being used in combination with multivariate analysis. Although principal component analysis provided insufficient separation between the sexes, linear discriminant analysis (LDA) was highly effective for sex determination. Using mummy hair as the LDA model enabled accurate sex prediction of the mummies, showing that, despite the age of the hair, the samples still contain the necessary elemental information for sex determination. For accurate sex determination of mummies using hair collected from living humans, magnesium had to be replaced by sodium due to significant differences in dietary habits. With this simple modification, hair from living humans in North America could be used to successfully predict the sex of individuals who lived more than 500 years ago in Peru. This work paves the way for broader use of non-skeletal sex determination methods within the field of archaeology, filling a significant gap.

[1]  G. Milner,et al.  Trace element distribution in human cortical bone microstructure: the potential for unravelling diet and social status in archaeological bones , 2020, Heritage Science.

[2]  Nathan T. Kearns,et al.  Linear Discriminant Analysis for Prediction of Group Membership: A User-Friendly Primer , 2019, Advances in Methods and Practices in Psychological Science.

[3]  Inmaculada Alemán Aguilera,et al.  Sex determination in a Spanish population based on sacrum. , 2018, Journal of forensic and legal medicine.

[4]  V. Dressler,et al.  Elemental hair analysis: A review of procedures and applications. , 2017, Analytica chimica acta.

[5]  Javier Irurita Olivares,et al.  Validation of the sex estimation method elaborated by Schutkowski in the Granada Osteological Collection of identified infant and young children: Analysis of the controversy between the different ways of analyzing and interpreting the results , 2016, International journal of legal medicine.

[6]  L. Grimaldi,et al.  Trace Elements in Scalp Hair Samples from Patients with Relapsing-Remitting Multiple Sclerosis , 2015, PloS one.

[7]  G. Dongarrà,et al.  Coverage intervals for trace elements in human scalp hair are site specific. , 2015, Environmental toxicology and pharmacology.

[8]  A. Seremak-Mrozikiewicz,et al.  Screening of Trace Elements in Hair of the Female Population with Different Types of Cancers in Wielkopolska Region of Poland , 2014, TheScientificWorldJournal.

[9]  R. Alonso,et al.  Analytical proposal for trace element determination in human hair. Application to the Biscay province population, northern Spain , 2014 .

[10]  D. Chakraborti,et al.  Environmental arsenic contamination and its health effects in a historic gold mining area of the Mangalur greenstone belt of Northeastern Karnataka, India. , 2013, Journal of hazardous materials.

[11]  Jocelyn S. Williams,et al.  Living and dying as subjects of the Inca Empire: Adult diet and health at Puruchuco-Huaquerones, Peru ☆ , 2013 .

[12]  D. Beauchemin,et al.  Solid sampling electrothermal vaporization inductively coupled plasma optical emission spectrometry for discrimination of automotive paint samples in forensic analysis , 2012 .

[13]  A. Parczewski,et al.  Examination of distribution of trace elements in hair, fingernails and toenails as alternative biological materials. Application of chemometric methods , 2012 .

[14]  R. Kronstrand,et al.  Society of Hair Testing guidelines for drug testing in hair. , 2012, Forensic science international.

[15]  M. Katzenberg,et al.  Seasonal fluctuations in diet and death during the late horizon: a stable isotopic analysis of hair and nail from the central coast of Peru , 2012 .

[16]  Jurii Kazimirovich Kovalionok.  IMPROVEMENT OF THE PROCEDURE OF CATTLE HAIR SAMPLE PREPARATION FOR CHEMICAL ANALYSIS , 2012 .

[17]  I. Michalak,et al.  Inter-relationship between elements in human hair: The effect of gender. , 2010, Ecotoxicology and environmental safety.

[18]  Ann H Ross,et al.  A Geometric Morphometric Approach to Sex Determination of the Human Adult Os Coxa , 2010, Journal of forensic sciences.

[19]  B. Arriaza,et al.  Were Chinchorros exposed to arsenic? Arsenic determination in Chinchorro mummies' hair by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) , 2010 .

[20]  R. Pastor,et al.  Dimensional variation in the proximal ulna: evaluation of a metric method for sex assessment. , 2008, American journal of physical anthropology.

[21]  E. Salin,et al.  Direct multielement determination of human hair by induction-heating electrothermal vaporization with ICP-MS , 2007 .

[22]  Ann H Ross,et al.  Sex Determination from Hand and Foot Bone Lengths * , 2007, Journal of forensic sciences.

[23]  M. Muikku,et al.  Assessment of occupational exposure to uranium by indirect methods needs information on natural background variations. , 2006, Radiation protection dosimetry.

[24]  K. Chojnacka,et al.  The influence of living habits and family relationships on element concentrations in human hair. , 2006, The Science of the total environment.

[25]  Eugénia Cunha,et al.  Forensic anthropology and medicine : complementary sciences from recovery to cause of death , 2006 .

[26]  E. Salin,et al.  Induction heating-electrothermal vaporization for direct mercury analysis of a single human hair strand by inductively coupled plasma mass spectrometry , 2005 .

[27]  W. Zhan,et al.  The use of electrothermal vaporization ICP-OES for the determination of trace elements in human hair using slurry sampling and PTFE as modifier , 2005 .

[28]  J. Štupar,et al.  Determination of chromium, manganese, lead and cadmium in biological samples including hair using direct electrothermal atomic absorption spectrometry , 1996 .

[29]  S. Hummel,et al.  Ancient Dna: "Recovery And Analysis Of Genetic Material From Paleontological, Archaeological, Museum, Medical, And Forensic Specimens" , 1994 .

[30]  S. Hummel,et al.  Ancient DNA , 1994, Springer New York.

[31]  J. Yoshinaga,et al.  Trace elements determined along single strands of hair by inductively coupled plasma mass spectrometry. , 1993, Clinical chemistry.

[32]  S. Ohmori.  Hair as a monitor for environmental pollution , 1984 .

[33]  G. Chittleborough.  A chemist's view of the analysis of human hair for trace elements. , 1980, The Science of the total environment.

[34]  T. S. West,et al.  The single element determination of trace metals in hair by carbon-furnace atomic absorption spectrometry. , 1976, Analytica chimica acta.

[35]  T W Phenice,et al.  A newly developed visual method of sexing the os pubis. , 1969, American journal of physical anthropology.