Analysis of heavy metals in hair

Modern research studies these days focus a lot on analysis of the balance of trace metals in humans. Investigations have shown that many trace elements can influence human health. For example, the excess of some toxic metals or deficiency of some essential metals can be the significant factor in many physical or psychological conditions such autism (Damodaran et al, 2010). One way to determine the presence and risks of heavy metals is by analysing human hair. It is also subjected to studies since it’s recognised as a potential repository of all elements which enters the body.

The most used method today for trace metal analysis in hair is Atomic Absorption Spectrometry (AAS). A sample of hair is cut to small pieces, then washed, dried and then digested in a microwave oven. After digestion, the sample is introduced in liquid form into AAS. Before introducing the sample, an instrument is calibrated with prepared working standards. Elements such as Pb, Cu, Zn, and Mg are analysed by graphite furnace. On the other hand, Hg is analysed by cold vapour method using mercury hydride system. Results are presented in µg/g.

Similar hair preparation during AAS is also done for Inductively Coupled Plasma (ICP) analysis. In one work, scientists were performing ashing in the furnace on 550ᴼC before microwave digestion. After the liquid sample is obtained, it is analysed in ICP. Results here for some specimens on the elements Cs, Cd, Th, and U, were presented in ng/g.

One more method which can be used for heavy metals analysis is X-ray fluorescence (XRF). Prior analysis, a sample is washed with acetone and water, and then dried in Petri dishes under an infrared lamp for 3 hours. Calibration of an instrument is done with some standard reference material which has similar properties as the hair sample. The XRF analyser is using the measured intensity of fluorescence of each element from the sample and combines it with calibration data to give the output of concentration in ppm. Analysis with XRF showed limits of detection below 10ppm for Mn, Fe, Ni, Cu, Zn, As, Pb, Se, and Sb.

M. Damodaran L. Priya & A. Geetha (2010), Level of Trace Elements (Copper, Zinc, Magnesium, and Selenium) and Toxic Elements (Lead and Mercury) in the Hair and Nail of Children with Autism

S.K. Sahoo et al. (2015), Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Ni_ska Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe)

If you would like to do hair testing and find it difficult to locate the best laboratory please contact us and let us help you or you can do the test yourself using hair testing kit listed below.