EDTA间接滴定法快速测定造纸废水中硫化物

提出了快速测定造纸废水中硫化物的EDTA间接滴定新方法.先将水样酸化,使其水中的HS-及S2-离子全部转化为H2S,然后加入过量的金属锌,反应产生的大量H2作为载气,与一并逸出的H2S气体通入热的NH3-NH4Cl缓冲溶液及已知量且过量的Zn2 标准吸收液中,当ZnS沉淀完全后,以EBT为指示剂,用EDTA标准溶液滴定剩余的Zn2 至终点.结果表明,改进后的方法简单、快捷、干扰小,测定结果的相对标准偏差＜3.0%,回收率为93.4%～96.8%.利用t检验法对测定结果进行了显著性检验,它与标准法之间未见有显著性差异.     

EDTA络合溶胶-凝胶法制备Ca3Co4O9粉体

钴基氧化物Ca3Co4O9是一种新型的中高温热电材料。本文以金属醋酸盐和乙二胺四乙酸(EDTA)为原料,利用EDTA络合溶胶-凝胶法制备了Ca3Co4O9粉体,通过X射线衍射(XRD)、热重-差示扫描量热分析(TG-DSC)、傅利叶变换红外光谱(FT-IR)、X射线能谱仪(EDX)和扫描电子显微镜(SEM)等手段对Ca3Co4O9进行表征。实验结果表明,干凝胶在700-900℃条件下恒温煅烧2h,即可获得纯相Ca3Co4O9片状晶体,其晶粒尺寸约为1-2μm。     

Selective electrochemical machining of the steel molds in hot isostatic pressing of Ti6Al4V powder

Anodic dissolution is proven to be an effective method to remove stainless steel molds from Ti6Al4V compacts obtained from powder by hot isostatic pressing. Two different working solutions were studied: 2?M NaCl and 2?M NaCl?+?0.05?M Na₂EDTA. While both were capable of removing the steel mold, the latter was also capable of removing the diffusional layer made by the intermetallic phases generated between titanium and steel during the compaction process.     

乙二胺四乙酸在纳米WC／Co复合粉制备中的应用

本文在喷雾转换法制备WC／Co纳米复合粉的基础上,采用乙二胺四乙酸与碳酸钴复合法制备高钴含量的WC／Co纳米复合粉,突破了原有技术的钴含量质量分数上限7％的瓶颈限制。采用DSC—TG分析、SEM分析、XRD分析等方法,对乙二胺四乙酸和碳酸钴的参与反应的机理进行了研究,并确定了采用新工艺制备WC／Co纳米复合粉的相关参数。实验结果表明：乙二胺四乙酸与碳酸钴反应所得有机钴盐为一种溶解度较高的螯合物,在较低温度下煅烧可分解,适用于WC／Co纳米复合粉前驱体溶液中钴含量的调节,避免了Cl-、NO3-等杂质离子的引入。通过新的复合‘工艺制备得到了适用于高温流态化床生产的前驱体粉末,最终制备得到钴含量质量分数8％的WC—Co纳米复合粉。     

改进的EDTA法检测饲料级硫酸锰中的锰

采用改进的乙二胺四乙酸二钠（EDTA）法对饲料级硫酸锰进行测定,方法步骤简便、快速省时、准确度高、重复性好,与硝酸铵法结果接近。     

影响稳定土中石灰剂量测定结果的因素分析

简要介绍了无机结合料稳定土的概念及特点,分别阐述了稳定土中结合料剂量测定的标准方法、测定原理及步骤,并先后分析了标准曲线,化学试剂,样品含水量等试验因素对测定结果的影响,以期指导实践。     

中性镀镍溶液柠檬酸钠的测定

柠檬酸钠含量的准确检测对中性镀镍溶液的维护是非常重要的。有些中性镀镍溶液还含有氯化物、光亮剂和润湿剂,这些物质对常见的分析方法有干扰,因此分析柠檬酸钠含量时必须针对镀液的成分选择适当的方法。列举了几种分析方法供从事镀液监控分析工作的同行参考。     

Use of Lysozyme,Nisin, and EDTA Combined Treatments for Maintaining Quality of Packed Ostrich Patties

ABSTRACT: The antimicrobial effectiveness of lysozyme, nisin, and ethylene diamine tetraacetic acid (EDTA) combination treatments (Mix₁: 250 ppm lysozyme, 250 ppm nisin, 5 mM EDTA; Mix₂: 500 ppm lysozyme, 500 ppm nisin, 5 mM EDTA) on bacterial growth of ostrich patties packaged in air, vacuum, and 2 different modified atmospheres (MAP₁: 80% O₂, 20% CO₂; MAP₂: 5% O₂, 30% CO₂, 65% N₂) was evaluated. Moreover, the lipid oxidation was evaluated as well as color and sensory characteristics. The growth of total viable counts and lactic acid bacteria were strongly inhibited by the antimicrobial treatments in all the running time (Inhibition Index >97%) whereas for Enterobacteriaceae and Pseudomonas spp. lower inhibition indices from 12% to about 28% were observed. The lipid oxidation was more pronounced in the control respect to the treated meat patties. Moreover, the mixture at low concentration of lysozyme and nisin showed the best antioxidative effect. High concentrations of lysozyme and nisin showed the greatest color loss. Also, off-odors for the untreated patties developed faster than the treated samples. Practical Application: Great interest is developing in food bio-preservation, because of the ever-increasing needs to protect consumers' health and to valorize the naturalness and safety of food products.