Titanium nitride as a coating for surgical instruments used to collect human tissue for trace metal analysis

When metallic surgical instruments are used to collect human tissue, metal contamination may occur, making accurate ultra-trace metal determinations very difficult. In order to reduce this risk as much as possible, surgical instruments made from a stainless-steel core covered by a film of titanium nitride, a very hard compound with high chemical stability and very good wear resistance, were prepared. The degree of risk from trace metal contamination during sample collection was investigated by neutron activation analysis and a radio-release in vitro serum test. As examples of their application, the titanium nitride coated instruments were used to determine Co, Cr and W in the skin of unexposed subjects and of uraemic patients under regular dialysis treatment.