Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES）...Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES） and electrothermal atomic absorption spectrometry （ETAAS）, Due to the potential spectral interferences of As and Fe in the quantification of Cd, two methods were used for the background compensation. The first method was based on the use of a deuterium lamp （BGCD2 mode）. The second one required a Cd hollow cathode lamp pulsated with a current for which the intensity varies in the course of time （BGCSR mode）. The results showed that the choices of the analytical technique and the method used for the background compensation depend on the Cd, As and Fe concentrations in the solution and the concentration ratios As/Cd or/and Fe/Cd. In comparison with the ICP-AES and the ETAAS in combination with the BGCD2 mode, it was shown that the high-speed self-reversal method （HSSR） was a more appropriate method to correct As and Fe spectral interferences during the Cd measurements. On the other hand, depending on the Cd concentration, it was established that no significant Fe interference occurred during the Cd determination even if Fe concentration was 50 mg/L, reflecting the efficiency of the HSSR method to overcome the Fe interferences in the determination of Cd concentration by ETAAS without any matrix modifier in water extracts.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Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES） and electrothermal atomic absorption spectrometry （ETAAS）, Due to the potential spectral interferences of As and Fe in the quantification of Cd, two methods were used for the background compensation. The first method was based on the use of a deuterium lamp （BGCD2 mode）. The second one required a Cd hollow cathode lamp pulsated with a current for which the intensity varies in the course of time （BGCSR mode）. The results showed that the choices of the analytical technique and the method used for the background compensation depend on the Cd, As and Fe concentrations in the solution and the concentration ratios As/Cd or/and Fe/Cd. In comparison with the ICP-AES and the ETAAS in combination with the BGCD2 mode, it was shown that the high-speed self-reversal method （HSSR） was a more appropriate method to correct As and Fe spectral interferences during the Cd measurements. On the other hand, depending on the Cd concentration, it was established that no significant Fe interference occurred during the Cd determination even if Fe concentration was 50 mg/L, reflecting the efficiency of the HSSR method to overcome the Fe interferences in the determination of Cd concentration by ETAAS without any matrix modifier in water extracts.
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.
