This paper studies the characterization of corrosion products formed on corroded and uncorroded copper-containing intrauterine devices stored at room temperature for a period of 30 months. The experimental techniques used were X-ray photo-electron spectroscopy and Auger electron spectroscopy. The compounds found were cuprite (Cu2O) and tenorite (CuO). The latter was the main compound formed on corroded samples, forming thin tarnish films.
PIP: Metallurgists in Madrid, Spain, conducted a study to identify the corrosion products formed on the copper (dimensions = 4.5 mm x 4 mm; thickness = 0.4 mm) of TCu 380 IUDs during storage at room temperature for 30 months. They placed the IUD in a sealed bag and sterilized it with ethylene oxide at 40 degrees Celsius and a relative humidity of 35%. The researchers used the experimental techniques of X-ray photoelectron spectroscopy and Auger electron spectroscopy to characterize the copper surfaces and the approximate element composition of the surface as a function of depth. They compared an uncorroded copper- containing IUD of red color with a corroded copper- containing IUD of brown color. The techniques revealed that copper cuprite (Cu2O) formed the inner layer and that tenorite (CuO) formed the outermost layer. CuO was the main compound (about 73%). Cu2O accounted for the red color on the uncorroded copper samples, while CuO accounted for the brown color on the corroded copper samples. CuO obstructs the diffusion of copper ions, which may reduce the effectiveness of a corroded copper IUD. During storage, copper-containing IUDs should be stored in completely sealed bags and under appropriate conditions of temperature and relative humidity to prevent copper corrosion.