Iron, copper, zinc and selenium in human liver tissue measured by X-ray fluorescence spectrometry

The content of iron, copper, zinc and selenium was measured by energy-dispersive X-ray fluorescence (XRF) spectrometry in normal liver tissue obtained at autopsy from 16 females and 12 males 46-87 years old. The precision of the XRF analysis, expressed by the coefficient of variation was: iron, 1.8%; copper, 3.2%; zinc, 1.0%; and selenium, 26.7%. In large liver samples, mean amount-of-substance contents of elements in dry liver tissue were: iron, 16.95 mmol/kg (range 7.90-27.31 mmol/kg); copper, 0.33 mmol/kg (0.08-0.76 mmol/kg); zinc, 5.12 mmol/kg (2.92-9.47 mmol/kg); selenium 0.02 mmol/kg (less than 0.004-0.04 mmol/kg). Furthermore the amounts of iron, copper and zinc were measured in wet-ashed Menghini needle biopsy specimens taken from the centre of 20 large liver samples. There was good agreement between results obtained in biopsy specimens and large samples concerning iron (r = 0.96, P less than 0.001) and zinc (r = 0.97, P less than 0.001), but not concerning copper (r = 0.66, P less than 0.01). XRF analysis appears to be a convenient method for element analysis in liver tissue and for measurement of iron and zinc in needle biopsy specimens.