STUDY OF LATENT FINGERPRINTS AND NEW DEVELOPERS BY PAPER SPRAY MASS SPECTROMETRY (PS-MS) Francisco Gomes, Claudio de Pereira, Kristiane Mariotti, Thieres Pereira, Nayara dos Santos, et al. Quimica Nova, 2024 STUDY OF LATENT FINGERPRINTS AND NEW DEVELOPERS BY PAPER SPRAY MASS SPECTROMETRY (PS-MS). In the criminal sphere, it is extremely important to identify perpetrators of crimes based on latent fingerprints (invisible to the naked eye) revealed at crime scenes and their corresponding objects. The present work aimed to evaluate four synthetic analogues of curcumin as possible IDL developers, and to compare their results with those of carbon black developer, as well as to reach the most adequate parameters in the use of the LTQ and FT-ICR mass spectrometers with the paper spray ionization (PS) source to study the chemical composition of the endogenous substances contained in the IDL. For this, a 24-1 factorial design was developed, where it was verified that the distance and voltage factors were the most influential for the increase in the response of signals, in the analysis of latent fingerprints by PS. Among the detected substances we can mention around 20 fatty acids, and squalene. Finally, four potential developers, synthetic analogues of curcumin, were compared with carbon black developer. The revelation of latent fingerprints occurred efficiently, allowing the visualization of minutiae, such as bifurcation and end of line, making it possible to classify them, according to the Vucetich Fingerprint Classification System.
Viagra® and Cialis® blister packaging fingerprinting using Fourier transform infrared spectroscopy (FTIR) allied with chemometric methods Thieres M. C. Pereira, Josué A. Q. Júnior, Rafael S. Ortiz, Werickson F. C. Rocha, Denise C. Endringer, et al. Analytical Methods, 2014 The production of counterfeit drugs is a criminal problem that carries serious risks to public health worldwide. Herein, the chemical fingerprinting of blister packaging using Fourier transform infrared spectroscopy (FTIR) of authentic and counterfeit samples of Viagra® and Cialis® is demonstrated. Fifteen commercial samples (Viagra® and Cialis®) and thirty two counterfeit samples (Viagra and Cialis) were analyzed, and the FTIR data was subjected to chemometric treatment via unsupervised pattern recognition methods (principal component analysis, and hierarchical cluster analysis) and a supervised pattern recognition method (partial least squares discriminant analysis). ATR-FTIR spectra of the blister packaging of authentic Cialis® and counterfeit Cialis samples showed bands at 2976, 2904, 1431, 1326, 1243, 973, 691 and 608 cm−1, suggesting the presence of polyvinyl chloride (PVC) in its chemical composition. For authentic Viagra® and counterfeit Viagra samples, several distinct chemical profiles were observed in the ATR-FTIR spectra. Using unsupervised methods, samples were separated into three large groups: (i) counterfeit Viagra (seven samples made of PVC); (ii) authentic Viagra® (three samples made of poly(ethylene terephthalate)); (iii) Cialis (authentic and counterfeit) and some samples of Viagra (thirty seven made of PVC with additives of stearic acid derivatives, butyl hydroxy toluene or bisphenol A). Therefore, this suggests that three different types of forming films are used in the market for blister packaging used to contain inhibitors of PDE-5. Using supervised methods, all samples were correctly classified into their respective classes.
Effect of organic solvents on the physical-chemistry behavior of high density polyethylene (HDPE) and polypropylene (PP) Thieres Magaive Costa Pereira, Eloilson Domingos, Eustáquio Vinícius Ribeiro de Castro, Wanderson Romão, Geovane Lopes de Sena, et al. Polimeros, 2014 O mercado brasileiro de embalagens empregado ao armazenamento de petroleo e seus derivados vem crescendo a cada ano, sendo constituidas basicamente por polietileno de alta densidade (PEAD) e polipropileno (PP). Contudo durante o armazenamento, a matriz polimerica fica exposta ao oleo, comprometendo suas propriedades fisicas e consequentemente a durabilidade do material. Portanto, estudos relacionados com a interacao entre solventes orgânicos e a matriz polimerica tornam-se importantes. Neste trabalho, a interacao do PEAD e PP com diferentes solventes apolares (tolueno, n-heptano, n-decano e n-tetradecano) foram estudadas em funcao da temperatura (25, 50 e 80 oC). Os valores de ganho de massa, coeficientes de difusao, sorcao, permeabilidade e parâmetros de mecanismo de transporte foram calculados. O ganho de massa observado para o PP foi maior do que para o PEAD, em todas as temperaturas, sendo que o tolueno foi o solvente responsavel pelo maior ganho de massa, atingindo o equilibrio em um menor intervalo de tempo. Esse resultado corrobora com os valores de coeficiente de difusao e de permeabilidade, que aumentaram na seguinte ordem: n-heptano > n-decano > n-tetradecano. Uma ordem inversa foi observada para os solventes alifaticos quando os valores de coeficiente de sorcao foram calculados. O mecanismo de transporte foi tambem estudado atraves da regressao dos dados de sorcao, sendo classificado como anomalo.
New methodologies to study the aging of polyamide 11 (PA 11) in flexible pipes: X-ray fluorescence spectrometry and infrared spectroscopy Rio Pipeline Conference and Exposition Technical Papers, 2011
