This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in diffe...This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As（Ill/V）, Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）, by graphite furnace atomic absorption spectrometry （GFAAS）. The results showed that chitosan had a removal effect on Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）. Of these, the percent re- moval of Ni（II） was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd（II）, Cr（III/VI） and Ni（II）, though with poor efficiency for Pb（II）. Except As（III/V）, all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr（III/VI） peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan mo- lecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd（II）, Pb（II）, Cr（III/VI） and Ni（II） was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.展开更多
Concentration of cadmium in poppy seeds, semi-finished products and baked goods with poppy seeds was determined by graphite furnace atomic absorption spectrometry （GF-AAS）. Homogenous samples of poppy seeds and prod...Concentration of cadmium in poppy seeds, semi-finished products and baked goods with poppy seeds was determined by graphite furnace atomic absorption spectrometry （GF-AAS）. Homogenous samples of poppy seeds and products containing poppy seeds were digested by means of microwave digestion system by using of nitric acid and hydrogen peroxide as reagents. The measurements were carried out using an atomic absorption spectrometer with Zeeman background correction. Detection limit was 0.003 mg/kg. A total of 208 samples of poppy seeds （from years 2004-2009） and 17 samples of semi-finished and baked goods were analysed. The average content was 0.64 mg/kg （median 0.64 mg/kg） for poppy seeds and 0.079 mg/kg （median 0.069 mg/kg） for semi-finished and baked goods. The relative standard deviation was lower than 5% for all measurements.展开更多
This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some h...This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some heavy metal in particulate matters have been investigated at this area in order to elucidate temporal variations as well as major sources processes responsible for their formation. Air particulate samples were collected from three different locations situated around Tokat. These samples were determined for heavy metals by using Flame or graphite-furnace Atomic absorption spectroscopy. Particulate matter concentrations up to 52.43μg/m^3 were observed in sampling area. The initial results of the chemical analysis showed that concentration values of heavy metals in air particles observed were higher than the World Health Organization （WHO） guideline limit values.展开更多
基金supported by the Natural Science Foundation of China(No.30972289)Ocean Public Welfare Scientific Research Special Appropriation Project(No.201005020)
文摘This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As（Ill/V）, Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）, by graphite furnace atomic absorption spectrometry （GFAAS）. The results showed that chitosan had a removal effect on Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）. Of these, the percent re- moval of Ni（II） was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd（II）, Cr（III/VI） and Ni（II）, though with poor efficiency for Pb（II）. Except As（III/V）, all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr（III/VI） peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan mo- lecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd（II）, Pb（II）, Cr（III/VI） and Ni（II） was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.
文摘Concentration of cadmium in poppy seeds, semi-finished products and baked goods with poppy seeds was determined by graphite furnace atomic absorption spectrometry （GF-AAS）. Homogenous samples of poppy seeds and products containing poppy seeds were digested by means of microwave digestion system by using of nitric acid and hydrogen peroxide as reagents. The measurements were carried out using an atomic absorption spectrometer with Zeeman background correction. Detection limit was 0.003 mg/kg. A total of 208 samples of poppy seeds （from years 2004-2009） and 17 samples of semi-finished and baked goods were analysed. The average content was 0.64 mg/kg （median 0.64 mg/kg） for poppy seeds and 0.079 mg/kg （median 0.069 mg/kg） for semi-finished and baked goods. The relative standard deviation was lower than 5% for all measurements.
文摘This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some heavy metal in particulate matters have been investigated at this area in order to elucidate temporal variations as well as major sources processes responsible for their formation. Air particulate samples were collected from three different locations situated around Tokat. These samples were determined for heavy metals by using Flame or graphite-furnace Atomic absorption spectroscopy. Particulate matter concentrations up to 52.43μg/m^3 were observed in sampling area. The initial results of the chemical analysis showed that concentration values of heavy metals in air particles observed were higher than the World Health Organization （WHO） guideline limit values.
