New tool studies hair to say what one ate, where one travelled

LONDON - Variation in sulphur concentration in the hair can reveal one’s recent diet and the places one has been to. A new laser tool based on this can be very handy to investigators tracking terrorists.

This tool shows up changes in a person’s eating habits and his or her movements between different countries.

Known as the “laser ablation” method, it detects variations in the sulphur isotopes of a chemical throughout the length of a single human hair. Isotopes are atoms with an equal number of protons and electrons but different numbers of neutrons.

Researchers from LGC Chemical Metrology Lab and University of Oviedo in Britain and Spain, respectively, who developed this method, focussed on the most abundant sulphur isotopes in hair keratin, sulphur-32 (32S), which accounts for about 95 percent and sulphur-34 (34S), which makes up around four percent.

This proportion can change slightly in response to people’s diets and if they travel from one country to another, and the technique is able to detect these small variations.

The laser works by making contact with the selected hair fragment, generating an aerosol, which later ionises within plasma, with the spectrometer providing the exact proportions of the sulphur isotopes.

“The advantage of this method, compared with others, is the high resolution resulting from use of the laser,” Santamara-Fernndez of LGC, who led the study. This advance has enabled the scientists to confirm that sulphur variations in hair can be linked to peoples’ geographical movements, said a LGC release.

These findings were published in the current issue of Analytical and Bioanalytical Chemistry.