悬浮体制样石墨炉原子吸收光谱法直接测定食品中的Cu、Zn、Mn

本文提出以 PTFE作为化学改进剂 ,悬浮体制样石墨炉原子吸收光谱法( GFAAS)测定食品中痕量 Cu、Zn、Mn的新方法。对 GFAAS测定 Cu、Zn、Mn的条件进行了优化。在选定的实验条件下 ,测定 Cu、Zn、Mn的特征质量分别为 3.1 pg、0 .8pg和 1 .8pg。采用水溶液工作曲线法直接分析了食品试样中的痕量 Cu、Zn、Mn,其测定结果与参考值相一致。本方法无需任何化学前处理 ,灵敏、简便。

石墨炉原子吸收法直接测定固体样品中痕量钴

本文研究了石墨炉原子吸收法直接测定固体样品中痕量钴。该方法无须对样品进行干法或湿法消解 ,将固体样品研磨后 ,过 2 0 0目筛 ,加入 0 .15%琼脂溶液 ,均匀悬浮 ,由石墨炉自动进样测定。本法准确、简单、无玷污、无损失 ,回收率为 90 %— 96%。

石墨炉原子吸收光谱法规定全血铅的方法研究

目的:建立一种新的血铅测定方法。方法:选择测定最佳条件,采用5%的4—甲基氢氧化铵做为一种新的稀释剂,用石墨炉原子吸收法测定全血铅。结果:本法的检出限为11pg,相对标准偏差为2.5%～4,4%,回收率为94%～99%。标准曲线在。0～100μg/L范围内线关系良好。结论:本法简便、快速、灵敏,准确度高,精密度好,适用好大量的日常样品检测,结果满意。

Chitosan Removes Toxic Heavy Metal Ions from Cigarette Mainstream Smoke

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.

Content of Cadmium in Poppy Seeds and Poppy Seeds Containing Products Marketed in Czech Republic

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.

The Assessment of Air Pollution during 2013 and 2014 in Tokat Province

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.

A Novel Method for Producing Hydrogen from a Hydrocarbon Liquid Using Microwave In-liquid Plasma

The in-liquid plasma method is a technology in which plasma of several thousand degrees Kelvin is generated within bubbles in a liquid. The purpose of this study is to enhance the hydrogen production rate from waste oils by using in-liquid plasma. Two types of microwave in-liquid plasma apparatus are adopted for hydrogen production. One is a conventional MW （microwave） oven, the other is a microwave generator with a waveguide to apply the in-liquid plasma steam reforming method in n-dodecane. The produced gas is 58%-90% hydrogen in these methods. The hydrogen production rate is improved by stabilization of the bubble growth. The gas production rate by plasma feeding steam in n-dodecane is 1.4 times higher than that without feeding steam.

强流高电荷态Pb离子束的产生与优化研究(英文)

随着原子物理及表面物理研究的发展,高电荷态金属离子束的需求日益增多.近来,在中国科学院近代物理研究所14.5GHzLECR3离子源实验平台上,以炉子法产生的铅离子束作为研究对象,进行了一系列ECR离子源关键参数(如:磁场、炉子功率、掺气等)影响高电荷态铅离子束产额的实验研究,在此基础上,调整优化了LECR3离子源的状态参数,从而获得了强流高电荷态铅离子束18eμA207pb30+和6.7eμA207pb37+.