Desenvolvimento de métodos para determinação de chumbo e níquel em produtos cosméticos e cabelo por GF AAS

Abstract

The world market of cosmetics and perfumes billions of dollars a year and every time new products are available to the consumer. It is therefore very important to ensure the quality and safety of such products. Thus the analysis of inorganic contaminants in cosmetic products is of great importance because of possible contamination and adulteration that may occur during the processing steps, packaging and storage products. There are few studies in the literature related to the determination of inorganic contaminants in cosmetics. and the analytical techniques used by the manufacturers and governmental institutions also require decomposition steps of the sample representing sources of errors and contamination. In this context, this work has focused primarily on the development of simple and rapid methods for determination of lead and nickel in cosmetic products (perfumes, hair dyes and makeup) and in samples of human hair BY graphite furnace atomic absorption spectrometry. The work consists of three parts. The first objective is to develop and validate methods for the determination of lead in samples of hair and hair dyes employing slurry sampling and GF AAS. To prepare suspensions the samples were diluted in 2.5% v/v HNO3 and 1.5 % v/v H2O2.and the optimal conditions of analysis as permanent modifiers, pyrolysis and atomization temperatures, times, pyrolysis and chemical modifier in solution were evaluated in order to achieve greater analytical efficiency. The analytical data supported the feasibility of the method for determining both lead as in hair samples for the determination of analyte in hair dyes. You can check the results, that higher concentrations of lead were found in hair samples of users of hair dye and dye dark cream color. In the second part, methods employing alkaline solubilization of the samples of lipstick and slurry sampling for samples of shade, with subsequent quantification of lead by GF AAS were developed. Ideal conditions of sample preparation were established by multivariate optimization and temperature program for each method was optimized through pyrolysis and atomization curves. The methods were validated and applied to analyze 22 samples and 15 samples of lipstick shade of different brands and colors bought locally. The presence of lead was detected in 21 of 22 samples, ranging from 0.27 to 4.45 g-1. As for the samples shadow the lowest concentration of lead detected was 0.41 g g-1 and the highest 7.08 g g-1. The last section was optimized and validated a method for direct determination of nickel in perfumes, also by GF AAS. The results obtained for the validation parameters indicated that the proposed method is efficient and reliable, with high sensitivity, with limits of detection and quantification of the order of 0.63 and 2.11 g L-1, respectively. A higher concentration of nickel was detected in samples of perfume imported water, with concentrations ranging from 7.13 to 21.7 L-1. Studies conducted demonstrated the potential strategies for sample preparation used in this study for the analysis of cosmetics. It is believed that these strategies can be used for other analytes in the same or similar arrays evaluated in this thesis. Since the results obtained in the analysis of cosmetic products, demonstrate the need for greater quality control and the establishment of effective and specific laws that may control the presence of toxic metals in range products such studies demonstrated the capability of preparing strategies samples used in this study for the analysis of cosmetics. It is believed that these strategies can be used for other analytes in the same or similar arrays evaluated in this thesis. Since the results obtained in the analysis of cosmetic products, demonstrate the need for greater quality control and the establishment of effective and specific laws that may control the presence of toxic metals in such products.