ARS | Publication request: Rapid screening for zinc deficiency using portable x-ray fluorescence in fingernails

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: March 29, 2012
Publication Date: March 29, 2012
Citation: Fu, K.A., Kehayias, J.J. 2012. Rapid screening for zinc deficiency using portable x-ray fluorescence in fingernails. Journal of Federation of American Societies for Experimental Biology. 26:1021.4.

Technical Abstract: Elemental composition of fingernails is a useful indicator of micronutrient status and may reflect an individual’s intake over time. Our objective was to determine if portable X-ray fluorescence (XRF) is a viable method to assess zinc content in fingernails in the field. Human fingernail samples ranging from 3 to 85 mg were collected with zinc-free steel clippers, cleaned and analyzed by non-destructive XRF without any further preparation. Some specimens were also analyzed by indirect current plasma emission spectrometry to provide absolute calibration. Reproducibility was found to be better than 2% for samples greater than 30 mg. Zinc was detected in human fingernails and animal hooves. XRF zinc values were compared against chemical and natural phantoms. Material from hooves served as high (swine, 135ug/g) and low (bovine, 52ug/g) standards. We concluded that portable, non-destructive XRF is a feasible method to determine zinc content in fingernails and an alternative to atomic absorption/emission spectrometry allowing for simple sample preparation and fast, automated analysis. Applications include field screening for zinc deficiency at the population level or to measure the efficacy of an intervention.