Estimating Aluminum leaching from Aluminum cook wares in different meat extracts and milk

A method of estimating Al leaching from Al cook ware in some meat extracts and liquid milk was investigated. In the present work four kinds of Al cook wares from four countries were chosen from the local market. Extracts of boiled meat (lamb, chicken, and fish) were used to make 10–50% (w/v) concentrations. In addition liquid fresh milk and long life milk were diluted to make 10–50% (v/v) concentrations. Weight loss (WL) method, atomic absorption, polarization method, and surface study were applied. The “estimated” Al intake per person from WL in 30% meat extract and milk range from 8.16 to 12.75 mg/h with fish extract having the highest leaching and chicken extract having the lowest leaching. Atomic absorption gave comparable results to that of WL. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by the FDA/WHO shows that Al leaching from Al cook wares may add high doses of Al into the diet.     

古代铜矿冶炼过程中稀土元素的变化研究

主要研究稀土元素在铜矿冶炼过程中的变化规律及其在冶金考古中的潜在应用。实验采用电感藕合等离子体发射光谱仪(ICP-AES)测试了湖北铜绿山、宁夏照壁山、山西中条山和内蒙古林西大井古代矿冶遗址的铜矿石，炼渣和铜锭的稀土元素含量，通过对其稀土总量和稀土配分模式的对比研究，探讨了稀土元素在古代铜矿冶炼过程中的化学行为。结果发现稀土元素在铜矿冶炼过程主要富集在炼渣中，金属铜中的稀土元素含量很低。因此，要想根据青铜器中的稀土元素特征示踪铜料来源，是很难实现的。通过对比各矿冶遗址的铜矿石、炼渣和铜锭的稀土配分曲线，发现炼渣的稀土配分曲线为判断古代所使用的冶炼技术及铜矿石的输出路线提供了可能。     

食品接触(塑料器皿)总迁移量测试的替代试验方法

针对欧盟法规(EU)10/2011规定,测定食品接触材料(塑料器皿)的总迁移量时,需将塑料制品置于模拟液中于40℃浸泡10d,检测周期过长的问题,试验了在几种不同的模拟液中改变浸泡温度及时间,以期达到缩短检测周期的目的。最终选择了以下几种浸泡条件:1以乙醇-水(10+90)混合液作为模拟液,于100℃浸泡88h;2乙酸-水(3+97)溶液为模拟液,于100℃浸泡6h;3乙醇-水(95+5)混合液为模拟液,在60℃浸泡40h;4异辛烷为模拟液,于60℃浸泡5h。浸泡结束后,将模拟液移入已称至恒重的蒸发皿(m1)中,蒸发至干,移入105℃烘箱中放置过夜并称至恒重(m2),根据m2与m1的差值(残渣量)除以浸泡体积即得总迁移量。采用上述改进的浸泡条件,不仅缩短了检测时间,而且能满足相关法规的要求。     

大学物理实验CAI课件的研制

本文介绍了大学物理实验 Ｃ Ａ Ｉ 课件的研制。     

ICP-AES法同时测定搪瓷餐具中铅镉锑镍的溶出量

采用ICP-AES法同时测定搪瓷餐具中铅、镉、锑、镍的溶出量,并对ICP-AES法测定乙酸（4％）浸泡液时分析线的选择,入射功率、护套气流量、载气压力的影响,以及基体和共存离子的干扰等进行研究。方法简便快速,回收率为100．8-104．0%,相对标准偏差为0．66％～1．75％。