EDTA交换法制备脑灌注显像剂99Tcm-ECD--反应条件研究

用脂溶性分数和放射化学纯度两项指标,系统地观察了以ＥＤＴＡ作为交换配体（转移螯合剂）时,制备脑灌注显像剂＾９９Ｔ制剂的反应条件及其稳定性。结果表明,用ＥＤＴＡ交换法标记＾９９Ｔｃ＾ｍ－ＥＣＤ时,放射性浓度对标记影响不大,ｐＨ５￣８范围宽,容易标记,ＥＤＴＡ用量为３６０μｇ和反应体积在２￣６ｍＬ为宜;＾９９Ｔｃ＾ｍ－ＥＣＤ在不同ｐＨ的溶液中可稳定保存。     

EDTA分光光度法测定铸造锌合金中铜

试样用盐酸,过氧化氢溶解,在醋酸－醋酸钠介质中,ＥＤＴＡ与Ｃｕ（Ⅱ）生成１＋１兰色配合物,借以进行光度测定,铜量在０－１５ｍｇ／１００ｍｌ范围内符合比尔定律。     

钨酸钙核／卤化银壳微晶乳剂的二次定影研究

近２０年来,随着卤化银微晶合成技术的进步,合成出了诸如Ｔ－颗粒、核壳乳剂和外延复合颗粒乳剂等性能优异的微晶体,极大地提高了乳剂的感光性能．但这些乳剂也有一个共同的缺点,即大量消耗贵金属银,且未成影像的银均随定影过程而浪费．为改善此类乳剂的不足,各国科...     

EDTA容量法测定反应炉石膏排渣中氟化钙量

本法基于将试样与碳酸钠溶液共沸使硫酸钙转化为碳酸钙,加入醋酸使碳酸钙溶解与氟化钙分离。将分离后的氟化钙溶于盐酸-硫酸-硼酸混合液,在pH> 12 介质中,用EDTA标准溶液滴定[1]。     

火电机组锅炉的EDTA化学清洗

对火电机组锅炉EDTA化学清洗的研究和应用进行了综述,主要内容包括清洗方法的原理、影响清洗效果的主要因素以及清洗废液回收处理的方法。     

EDTA滴定法测定锡铋焊料中铋

采用盐酸-硝酸溶样,高氯酸冒烟,在硝酸介质中将锡转化成偏锡酸沉淀与铋进行分离,最后用EDTA滴定法测定铋含量,建立了一种测定锡铋焊料中高含量铋的方法。考察了硝酸用量、锡含量和干扰离子对测定的影响。结果表明,硝酸用量为30 mL时,锡可完全沉淀,铋不会水解,锡铋分离效果好;偏锡酸沉淀会对铋产生吸附和包裹,通过控制试样的称样量可降低干扰;与铋共存的 Cu²⁺、Fe³⁺、Sb、Te、In³⁺干扰滴定,其中Cu²⁺、Fe³⁺、Sb、Te可通过加入掩蔽剂或控制滴定条件消除干扰,In³⁺与EDTA络合,使铋的测定结果偏高,可用原子吸收光谱法或电感耦合等离子光谱法测定后从滴定总量中进行扣除。本方法用于Sn20-Bi焊料和Sn38-Bi焊料中铋的测定,测得结果与氢溴酸挥发-EDTA滴定法一致,相对标准偏差（RSD, n=8）小于或等于0.14%。     

Simultaneous recovery of heavy metals and degradation of organic species – copper and ethylenediaminetetra‐acetic acid (EDTA)

In mixed industrial effluent the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of metal is reduced by the presence of the organic species. Results are presented for a copper–ethylenediaminetetra‐acetic acid (EDTA) system in which both effects occur. An electrochemical cell alone can be used to recover copper in pH range 1.5–4.5 but is not capable of achieving complete mineralisation of EDTA by anodic oxidation. A photolytic cell alone can achieve the destruction of EDTA at pH 3.5 but leaves copper in solution. A combined photolytic–electrochemical system using an activated carbon concentrator cathode achieves the rapid simultaneous destruction of EDTA and recovery of copper. © 2000 Society of Chemical Industry     

Biological degradation of EDTA: Reaction kinetics and technical approach

The microbial mineralization of EDTA in waste water by a mixed culture was studied with suspended and immobilized cells. Efficient degradation of EDTA could be achieved, though the chelator is stated not to be biodegradable. A complete set of kinetic parameters was determined that enables the modelling of EDTA degradation and, related to this, bacterial growth, ammonium release, maintenance requirement as well as oxygen uptake. In order to obtain important technical scale-up parameters, the microorganisms were immobilized on different carrier particles and employed in continuously operated three-phase airlift-loop reactors. The reactors could be operated at a dilution rate up to D=1·2 h⁻¹ (D≪μ_max) that, at an EDTA concentration of 450 mg dm⁻³, led to EDTA degradation rates up to 12·8 kg m⁻³ day⁻¹. The extent of EDTA deg-radation remained constant at 95–99% with increasing values of D. Achieved kinetic parameters of the biofilm systems were compared with those which were obtained from experiments with suspended cells. © 1998 Society of Chemical Industry     

EDTA滴定法测定镍镁合金中镍和镁

建立了EDTA络合滴定法测定镍镁合金中镍和镁含量的分析方法。试样以硝酸、滴加盐酸溶解,分取一定体积的试液,加柠檬酸掩蔽铁离子,以丁二酮肟沉淀镍,用硝酸和高氯酸破坏沉淀剂,以紫脲酸铵作指示剂,用EDTA标准溶液滴定镍含量;同时,另取部分试液,以铜试剂预先分离镍基体,并以盐酸羟胺、氰化钾、三乙醇胺等掩蔽剩余干扰离子,以铬黑T为指示剂,用EDTA标准溶液滴定镁含量。对沉淀剂进行探讨,结果表明,测定镍时,加沉淀剂丁二酮肟与其络合沉淀,选择性好;而测定镁时,选择铜试剂络合沉淀基体镍和其他干扰离子,滤液可直接用于镁离子的测定,干扰少。对镍镁合金样品中镍、镁含量进行多次平行测定,相对标准偏差(RSD,n=6)分别为0.23%~0.57%和0.76%~0.90%。并模拟镍镁合金的主要成分及含量合成试样溶液进行测定,结果与理论值一致。将方法应用于镍镁合金实际样品分析,结果与参照方法结果一致。     

EDTA络合滴定法测定稀土镁中间合金中镁

研究了分别采用草酸和氢氧化铵沉淀分离稀土镁中间合金中的稀土,EDTA络合滴定法快速测定电解稀土镁中间合金中镁的两种方法。分析对比了两种方法的适用范围,结果表明,草酸分离稀土方法简便快速,但草酸用量需控制在理论用量的1.2～1.7倍,且合金中铁含量要求小于0.5%;氢氧化铵分离稀土方法分析流程比前者长,但可将主要干扰杂质铁分离完全,终点敏锐。两种方法均已应用于实际产品检测中,测定结果的相对标准偏差为0.69%～1.23%,回收率在97.2%～102.5%之间。