Recently, the demand for REEs （rare earth elements） has been heavily increasing, as they are used in many high-tech products （e.g., because of their specific magnetic behavior）. As a result, the supply situation f...Recently, the demand for REEs （rare earth elements） has been heavily increasing, as they are used in many high-tech products （e.g., because of their specific magnetic behavior）. As a result, the supply situation for REEs is worsening and the world market is depending on Chinese exports, so that it may be worthwhile to recycle e-waste （electronic waste） in European countries. This article describes an analytical method to analyze REEs in different kinds of e-waste with the help of a simultaneous ICP-OES （ICP optical emission spectrometer）. The task is challenging because samples show significant differences in terms of major, minor and trace element concentrations. Depending on the field of application, the level of matrix elements and target elements differs completely, resulting in a wide variety of spectral interferences. The method presented in this article allows an accurate quantification of REEs as well as a high sample throughput. In addition to REEs, other elements of economic interest can be determined in the same way. The development of a sample preparation process is another important issue and considered as well.展开更多
This study aimed to evaluate the EDC （endocrine disruptors compounds） in the city of Sao Paulo＇s water sources, from samples collected at predetermined sampling points and to evaluate the adsorptive capacity of the...This study aimed to evaluate the EDC （endocrine disruptors compounds） in the city of Sao Paulo＇s water sources, from samples collected at predetermined sampling points and to evaluate the adsorptive capacity of these compounds in different types of activated carbon. The effects of these EDC on humans are not well established due to the necessary large exposure time for the effect＇s manifestation. After tests using powdered and granular activated carbon, all samples were filtered under vacuum using cellulose acetate membrane （0.45 μm） to remove eventual impurities, and posteriorly carded out the solid-phase extraction SPE （solid-phase extraction） and chromatographic analysis. The results lead to the conclusion that both powdered activated carbon have removal effectiveness of these compounds by adsorption. Furthermore, great amount of endocrine disruptors were found at several sampling points in river and city＇s water reservoirs, which shows different levels of pollution of water sources, some of them responsible for the watersupply of the city of Silo Paulo, Brazil.展开更多
文摘Recently, the demand for REEs （rare earth elements） has been heavily increasing, as they are used in many high-tech products （e.g., because of their specific magnetic behavior）. As a result, the supply situation for REEs is worsening and the world market is depending on Chinese exports, so that it may be worthwhile to recycle e-waste （electronic waste） in European countries. This article describes an analytical method to analyze REEs in different kinds of e-waste with the help of a simultaneous ICP-OES （ICP optical emission spectrometer）. The task is challenging because samples show significant differences in terms of major, minor and trace element concentrations. Depending on the field of application, the level of matrix elements and target elements differs completely, resulting in a wide variety of spectral interferences. The method presented in this article allows an accurate quantification of REEs as well as a high sample throughput. In addition to REEs, other elements of economic interest can be determined in the same way. The development of a sample preparation process is another important issue and considered as well.
文摘This study aimed to evaluate the EDC （endocrine disruptors compounds） in the city of Sao Paulo＇s water sources, from samples collected at predetermined sampling points and to evaluate the adsorptive capacity of these compounds in different types of activated carbon. The effects of these EDC on humans are not well established due to the necessary large exposure time for the effect＇s manifestation. After tests using powdered and granular activated carbon, all samples were filtered under vacuum using cellulose acetate membrane （0.45 μm） to remove eventual impurities, and posteriorly carded out the solid-phase extraction SPE （solid-phase extraction） and chromatographic analysis. The results lead to the conclusion that both powdered activated carbon have removal effectiveness of these compounds by adsorption. Furthermore, great amount of endocrine disruptors were found at several sampling points in river and city＇s water reservoirs, which shows different levels of pollution of water sources, some of them responsible for the watersupply of the city of Silo Paulo, Brazil.
