Instrumental effect on contamination of biomedical samples in the process of sampling

The effect of surgical instruments on the contamination of human soft tissues with trace elements in the course of sampling was examined. Samples were taken with the use of a common scalpel and a knife of titanium from a thyroid gland of a male patient who died in an automobile accident. In these samples, Ag, Co, Cr, Fe, Hg, Rb, Sb, Se, and Zn were determined by instrumental neutron activation analysis. The average concentrations of elements int he samples taken with the scalpel were higher than those in the samples taken with the knife by a factor of 1.4-2.5, and this factor was 48 for chromium. Statistically reliable differences were found only for Cr and Co because of high variances of concentrations caused by nonuniformly distributed trace elements in the bulk of the thyroid gland. Recommendations on the choice of sampling instruments in biomedical examinations were given. 27 refs.; 4 tabs