RESUMO
Lip balm may be encountered as physical evidence in cases involving sexual assaults, homicides, and kidnappings. Lip balm can be used as corroborative evidence by providing a potential link between the victim, accused, and the crime scene. For lip balms to be used as evidence, it is important to understand the diversity and their aging process under different conditions. Therefore, in this study, ATR-FTIR spectroscopy in conjunction with chemometric tools such as principal component analysis (PCA) and linear discriminant analysis (LDA) has been used for the objective identification and differentiation of 20 brands of lip balms. Moreover, lip balms on different substrates and wearing effects over time were also investigated. The results show that the PCA-LDA training accuracy was 92.5%, whereas the validation accuracy comes out to be 83.33%. A blind study using pristine samples was also performed which resulted in 80% PCA-LDA accuracy. PCA-LDA prediction of samples on various substrates showed a higher chemometric prediction accuracy for nonporous substrates (glass, plastic, and steel), than for porous substrates (cotton cloth, cotton swab stick, dry tissue paper, and white paper) for samples kept in room temperature and under sunlight for 15 days. The substrate study showed that the samples from various substrates could effectively generate respective spectra which can help in brand-level identification even after several days. The present method demonstrates a potential for lip balm samples to be used in forensic casework applications.
Assuntos
Medicina Legal , Lábio , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Discriminante , Análise de Componente Principal , HomicídioRESUMO
HYPOTHESIS: Drying-induced decrease in lip balm surface energy enhances virus adhesion due to the emergence of strong hydrophobic colloid-surface interactions. EXPERIMENTS: A protocol was developed for preparing lip balm coatings to enable physicochemical characterization and adhesion studies. Surface charge and hydrophobicity of four brands of lip balm (dry and hydrated) and human adenovirus 5 (HAdV5) were measured and used to calculate the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) energy of interactions between lip balm coatings and HAdV5 as well as four other colloids: HAdV40, MS2 and P22 bacteriophages, and SiO2. Quartz crystal microbalance with dissipation monitoring (QCM-D) tests employed SiO2 colloids, HAdV5 and hydrated lip balms. FINDINGS: Drying of lip balms results in a dramatic decrease of their surface energy (δΔGsws≥ 83.0â¯mJ/m2) making the surfaces highly hydrophobic. For dry lip balms, the interaction of the balm surface with all five colloids is attractive. For lip balms hydrated in 150â¯mM NaCl (ionic strength of human saliva), XDLVO calculations predict that hydrophilic colloids (MS2, P22, SiO2) may attach into shallow secondary minima. Due to the relative hydrophobicity of human adenoviruses, primary maxima in XDLVO profiles are low or non-existent making irreversible deposition into primary energy minima possible. Preliminary QCM-D tests with SiO2 colloids and HAdV5 confirm deposition on hydrated lip balms.
Assuntos
Dióxido de Silício , Ligação Viral , Coloides , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lábio , Propriedades de SuperfícieRESUMO
Rhodamine B is a synthetic dye used in many industries including cosmetics. Long-term contact may results neurotoxicity, genotoxicity and cancer. In the present work, a simple solvent extraction followed by rapid, sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometric method has been proposed for the identification and quantification of rhodamine B in lip balm samples for the first time to our knowledge. The best extraction was achieved using organic solvent n-hexane followed by sonication, centrifugation and evaporation. The chromatographic separation was attained in <1â¯min with Acquity™ BEH C18 reversed phase column and a tandem mass spectrometer. The limit of detection (LOD), limit of quantification (LOQ), linearity, precisions and accuracy of the proposed method were determined. The LOD and LOQ were found to be 0.1⯵g/kg and 0.4⯵g/kg, respectively. The linearity (R2) was obtained (>0.999) when analyzing low to higher range of concentrations. The precisions with relative standard deviation (RSD%) values in terms of repeatability (<2%, nâ¯=â¯5) and reproducibility (<3%, nâ¯=â¯5) were achieved. The accuracy in terms of recovery was obtained between 93% and 98%. The optimized procedures have been applied for the identification and quantification of rhodamine B in commercial lip balm samples from various brands and origin, and the amounts were obtained from not detected to 70.44⯵g/kg. The good quality conditions, negligible matrix influence and higher recovery values obtained throughout analysis have proved the suitability of the present method for the routine analysis of rhodamine B in lip balm samples. The achieved results could be used to approximate the application of rhodamine B from individuals either from Saudi Arabia or globally, and thus to improve the quality and safety of lip balm products.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cosméticos/química , Rodaminas/análise , Espectrometria de Massas em Tandem/métodos , Fracionamento Químico/métodos , Cromatografia de Fase Reversa/métodos , Hexanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Rodaminas/isolamento & purificaçãoRESUMO
Personal products, such as toothbrushes, have been used as both known reference and evidentiary samples for forensic DNA analysis. This study examined the viability of a broad selection of cosmetic applicators for use as targets for human DNA extraction and short tandem repeat (STR) analysis using standard polymerase chain reaction (PCR) conditions. Applicator types included eyeliner smudgers, pencils and crayons, eye shadow sponges, mascara wands, concealer wands, face makeup sponges, pads and brushes, lipsticks and balms, and lip gloss wands. The quantity and quality of DNA extracted from each type of applicator were examined by assessing the number of loci successfully amplified and the peak balance of the heterozygous alleles in each full STR profile. While degraded DNA, stochastic amplification, and PCR inhibition were observed for some items, full STR profiles were developed for 14 of 76 applicators. The face makeup sponge applicators yielded the highest proportional number of full STR profiles (4/7).
Assuntos
Técnicas Cosméticas/instrumentação , Cosméticos , Impressões Digitais de DNA , DNA/isolamento & purificação , Repetições de Microssatélites , Humanos , Reação em Cadeia da PolimeraseRESUMO
Rising global demand for natural products whose production is harmless to the environment has stimulated the development of natural cosmetics and, within this category, organics (95% organic raw materials). The image of environmentally friendly production is one of the strongest attractions of organic products. Lip balm is a cosmetic product similar to lipstick whose purpose is to prevent lip dryness and protect against adverse environmental factors. The product's characteristics are: resistance to temperature variations, pleasant flavor, innocuousness, smoothness during application, adherence and easy intentional removal. This work involved the development of a lip balm formulated with certified organic raw materials and the execution of stability tests: fusion point determination, evaluation of organoleptic characteristics (color, odor and appearance) and functionality evaluation (spreadability test). The formulation selected after the Preliminary Stability Test was submitted to the Normal Stability Test under the following storage conditions (temperature): Room Temperature (22.0 ± 3.0 ºC), Oven (40.0 ± 2.0 ºC) and Refrigerator (5.0 ± 1.0 ºC), for 90 days. Under the Refrigerator and Room Temperature conditions, spreadability proved adequate, but the surface presented white spots, characterizing the fat bloom, a phenomenon involving the recrystallization of cocoa butter. Storage at 40.0 ± 2.0 ºC (Oven) caused loss of functionality according to the spreadability test, in addition to changes in color, although the aspect was uniform since the fat bloom was not observed (white spots on the surface). The odor remained stable under all conditions as did the melting point, which had a mean of 72.9 ± 1.7 ºC throughout the course of stability testing (90 days).
O aumento da demanda global por produtos naturais, cuja produção não envolva nenhum dano ao meio ambiente, tem estimulado o desenvolvimento de cosméticos naturais e, dentro desta categoria, dos produtos orgânicos (que contêm 95% de matérias-primas orgânicas). O protetor labial é um produto cosmético semelhante ao batom que tem a finalidade de prevenir o ressecamento dos lábios, mantendo a hidratação, e protegê-los contra fatores ambientais adversos. Este trabalho envolveu o desenvolvimento de um protetor labial formulado com matérias-primas orgânicas e avaliação dos parâmetros de estabilidade, como ponto de fusão, características organolépticas e funcionalidade (teste de espalhabilidade). A formulação selecionada após o Estudo de Estabilidade Preliminar foi submetida à Avaliação Normal de Estabilidade, nas seguintes condições de armazenamento (temperatura): Ambiente (22,0 ± 3,0 ºC), Estufa (40,0 ± 2,0 ºC) e Geladeira (5,0 ± 1,0 ºC), por 90 dias. Nas condições de armazenamento em geladeira ou ambiente, a espalhabilidade foi adequada, mas a superfície apresentou pontos esbranquiçados, caracterizando o fenômeno chamado fat bloom, que está relacionado à recristalização da manteiga de cacau. O armazenamento à temperatura elevada (40,0 ± 2,0 ºC) provocou perda de funcionalidade, de acordo com o teste de espalhabilidade, e mudança de cor, apesar do aspecto permanecer uniforme, visto que não foi observado o fenômeno fat bloom. O odor manteve-se estável em todas as condições, assim como o ponto de fusão, com valor médio de 72,9 ºC ± 1,7 ºC durante todo o período de avaliação do teste de estabilidade (90 dias).