X-Ray fluorescence measurement of the zinc profile of a single hair.

Many trace elements appear in hair in concentrations related to those in the blood, but the relationship for zinc is complicated by disorders that probably affect its state in the blood. A built-to-order x-ray fluorescence spectrometer was used to measure, nondestructively, the concentrations of 16 elements in a 1-mm interval of a single hair. A scan along a hair strand, together with the known growth rate, enables the zinc concentration in the hair to be correlated with the time the hair was formed. A comparison with the blood concentration at the same time may reveal possible bodily disorders that affect the availability of zinc to incorporation in the hair. The instrument has been carefully calibrated for zinc, and we studied the conditions under which there can be losses or gains in the hair after sampling. The sample chamber will accommodate 16 separate holders, and each sample may be automatically measured according to a program pre-selected for it. The average zinc content of hair samples from foreign countries, some ancient specimens, and an interesting profile of a strand from an Iraqi woman are shown.