Overview of cocaine identification by vibrational spectroscopy and chemometrics.

The use of non-destructive forensic methods for cocaine identification is of outstanding importance, given the amount of samples seized. Techniques such as ATR-FTIR, Raman, and NIR spectroscopy have become alternatives to circumvent this problem, as they allow fast, cheap analysis, and enable the reanalysis of samples. When combined with chemometrics, these spectroscopic methods can be used to determine and quantify cocaine samples, meaning that the limitations of existing techniques can be overcome. This review article covers spectroscopic techniques for identifying cocaine in different forms and matrices, such as food and textiles, which are materials used for smuggling. The chemometric identification of cocaine in oral fluid and water is also discussed. In addition, vibrational spectroscopy techniques using portable equipment are described. This work seeks to evaluate the main chemometric applications of spectroscopic data and to find new perspectives on the identification of cocaine using chemometrics.

Hollow cathode plasma nitriding of medical grade Ti6Al4V: A comprehensive study.

Ti6Al4V used in biomedical applications still has several surface-related problems, such as poor bone compatibility and low wear resistance. In this work, the formation of a protective layer of titanium nitride obtained by plasma treatment in hollow cathode was studied, and the best experimental conditions were verified by a statistical factorial design of experiments. The samples were characterized in terms of their physical and chemical properties, correlating the effects of time (min) and temperature (°C). An achieved ideal condition was further analysed in terms of in vitro cytotoxicity, micro-abrasion, and electrochemical properties. The carried-out assessment has shown that nitrided condition has an improvement in wettability, microhardness, along with TixNy formation and roughness increment, when compared to pristine condition.