Ana Paula Fleig Saidelles

Determination of Cd and Pb in medicinal plants using solid sampling flame atomic absorption spectrometry

A procedure for trace determination of Cd and Pb in medicinal samples using solid sampling flame atomic absorption spectrometry (SS-F AAS) was developed for trace determination of Cd and Pb in medicinal plants. Powdered samples were mixed with high purity graphite and introduced as pellets (up to 100 mg) into a quartz device positioned above the burner and heated by air–acetylene flame. Oxygen flowing through the quartz device assure the complete combustion of sample. Combustion was started in 2 s after sample introduction and the produced vapours were subsequently dispersed into the flame. Calibration was performed using different masses of solid certified reference material (for Pb) or with reference solutions applied directly on graphite pellets (for Cd). Integrated absorbance mode was used and signals were integrated in less than 10 s. A deuterium background corrector was used throughout. Characteristic masses were 58 and 790 pg for Cd and Pb, respectively. Accuracy was checked using certified reference materials and the percent relative error was between −7 and 2% for Cd and between −2 and 3% for Pb. Relative standard deviations (repeatability) were always below 10% (n = 5). Limits of detection were 0.012 and 0.10 µg g−1 for Cd and Pb, respectively. The proposed procedure by SS-F AAS is simple and may be applied to conventional atomic spectrometers allowing the determination of Cd or Pb in 40 test samples by hour (excluding the steps for sample preparation).

Solid waste management in southern Brazil

A large amount of solid waste generated by the population leads to social, environmental and health problems, so it is important that the Brazilian municipalities have programs for solid waste management in order to reduce the effects of the mismanagement of these materials. Thus, the aim of this study was to characterize the solid waste management in southern Brazil. For data analysis, was used descriptive statistics. The data were obtained from IBGE, referring to the National Survey of Sanitation year 2008. With this study, it was revealed that all the municipalities in southern Brazil have solid waste management, but there is no selective collection in 52.4% of the municipalities of Parana State, 66.6% of the municipalities of Santa Catarina State and 66.5% the municipalities of Rio Grande do Sul State. In Brazil, the largest daily quantity of solid waste is destined for landfills, corresponding to 64.6%. Therefore, it is necessary constantly invest in solid waste management, with the aim of improving the services provided to the population and minimize social, environmental and health damage caused by improper management of solid waste.