ASSESSMENT OF THE CONTENT OF SELECTED TRACE-ELEMENTS IN SERUM OF TERMAND PRETERM NEWBORNS BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A method for the determination of 14 trace and ultra-trace elements (A l, Cd, Co, Cu, Li, Mn, Mo, Ni, Pb, Pt, Rb, Sb, Se and Zn) in serum of newborns by inductively coupled plasma mass spectrometry (ICP-MS) with ultrasonic nebulization is described. Cord blood samples were collect ed from term and pre-term newborns by means of a teflon catheter withi n 24 h from delivery. The eligibility criteria adopted in this study r equire that only ''normal'' (i.e. fully representative of their specif ic conditions) subjects be selected for blood collection. From this st andpoint, pre-term newborns suffering only from diseases derived from their status, i.e. really representative of the group under investigat ion, were included in the study. After centrifugation, serum aliquots were stored in metal-free plastic test tubes at -20 degrees C until an alysis. Sample treatment was kept to a minimum, i.e. serum samples wer e diluted 20-50-fold with 0.14 M HNO3 and spiked with suitable amounts of Rh and Tl, the internal standards, to account for nebulization eff ects and for instability of nebulization and ionization. To minimize t he effects of matrix interferences, blanks and calibrants were prepare d from synthetic solution containing the same major components as the real sample solutions. The analytical method adopted, i.e. ICP-MS dete rmination combined with ultrasonic nebulization, turned out to be full y suited to the aim of this study. Experimental data were statisticall y analyzed by parametric and non-parametric tests in order to assess t entative reference ranges of elemental concentrations. To this end, ne wborns were grouped by gestational age and body weight at the delivery . Results allow tentative reference values to be assessed for the abov e-mentioned elements in serum of newborns, with the only exception of Pt, which was below the detection power of the technique.