Heavy metal exposure remains a significant public health problem, particularly in sub-Saharan Africa where use of artisanal cookware made from recycled metallic materials is still common. In this study, the effect of ...Heavy metal exposure remains a significant public health problem, particularly in sub-Saharan Africa where use of artisanal cookware made from recycled metallic materials is still common. In this study, the effect of cookware composition, cleaning material, heating duration and temperature on metal migration from different cookware, including artisanal pans was investigated. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Locally fabricated cookware leached the highest levels of metals, where the levels of Pb (9.00 ± 0.80 × 10<sup>-2</sup> mg/l), Al (11.40 ± 0.02 × 10<sup>-2</sup> mg/l), Cd (5.80 ± 0.30 × 10<sup>-2</sup> mg/l), Cr (6.60 ± 0.03 × 10<sup>-2</sup> mg/l) and Ni (3.00 ± 0.01 × 10<sup>-2</sup> mg/l) were above the WHO permissible limits of heavy metals for drinking water. Steel wire was the most aggressive cleaning material to the cookware surfaces, followed by sand and then ash. For cookware heated at 100°C and above, an exponential relationship between temperature and the migration of Al, Pb and Cd was observed. The findings revealed heavy metal exposure from cookware usage, which poses potential health risks to the population. There is need for policies and civic education to minimize this exposure.</sup>展开更多
A localized surface plasmon resonance(LSPR) biosensor was prepared with gold nanospheres(Au NSs) coated on the tip face of the optical silica fiber. Au NSs with the sizes of 20 nm and 80 nm were used. The sensitivitie...A localized surface plasmon resonance(LSPR) biosensor was prepared with gold nanospheres(Au NSs) coated on the tip face of the optical silica fiber. Au NSs with the sizes of 20 nm and 80 nm were used. The sensitivities of Au NS_(20 nm) and Au NS_(80 nm) modified sensors to bulk refractive index(RI) variation are 82.86 nm/RIU and 218.98 nm/RIU, respectively. The Au NS_(80 nm) modified sensor was used for the detection of 40 bases DNA hybridization and the limit of detection is 50 nmol/L, where the 40-bases DNA probe was covalently linked with Au NS_(80 nm). The complementary DNA sequence in tris-acetate-EDTA(TAE) buffer solution was detected as the target DNA. This fiber sensor has the advantages of small sample consumption, easy fabrication and high sensitivity.展开更多
文摘Heavy metal exposure remains a significant public health problem, particularly in sub-Saharan Africa where use of artisanal cookware made from recycled metallic materials is still common. In this study, the effect of cookware composition, cleaning material, heating duration and temperature on metal migration from different cookware, including artisanal pans was investigated. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Locally fabricated cookware leached the highest levels of metals, where the levels of Pb (9.00 ± 0.80 × 10<sup>-2</sup> mg/l), Al (11.40 ± 0.02 × 10<sup>-2</sup> mg/l), Cd (5.80 ± 0.30 × 10<sup>-2</sup> mg/l), Cr (6.60 ± 0.03 × 10<sup>-2</sup> mg/l) and Ni (3.00 ± 0.01 × 10<sup>-2</sup> mg/l) were above the WHO permissible limits of heavy metals for drinking water. Steel wire was the most aggressive cleaning material to the cookware surfaces, followed by sand and then ash. For cookware heated at 100°C and above, an exponential relationship between temperature and the migration of Al, Pb and Cd was observed. The findings revealed heavy metal exposure from cookware usage, which poses potential health risks to the population. There is need for policies and civic education to minimize this exposure.</sup>
基金supported by the National Basic Research Program of China(No.2014M561055)the National High Technology Research and Development Program(No.2012AA101608)the National Natural Science Foundation of China(No.61401433)
文摘A localized surface plasmon resonance(LSPR) biosensor was prepared with gold nanospheres(Au NSs) coated on the tip face of the optical silica fiber. Au NSs with the sizes of 20 nm and 80 nm were used. The sensitivities of Au NS_(20 nm) and Au NS_(80 nm) modified sensors to bulk refractive index(RI) variation are 82.86 nm/RIU and 218.98 nm/RIU, respectively. The Au NS_(80 nm) modified sensor was used for the detection of 40 bases DNA hybridization and the limit of detection is 50 nmol/L, where the 40-bases DNA probe was covalently linked with Au NS_(80 nm). The complementary DNA sequence in tris-acetate-EDTA(TAE) buffer solution was detected as the target DNA. This fiber sensor has the advantages of small sample consumption, easy fabrication and high sensitivity.
