Electrical Conductance Studies in Aqueous Solutions with Ascorbate Ions

Conductivity measurements in dilute aqueous solutions of L-ascorbic acid, sodium-L-ascorbate, magnesium-L-ascorbate, calcium-L-ascorbate and ferrous-L-ascorbate were performed in the (288.15 to 323.15) K temperature range. The limiting molar conductances of the ascorbic anion, λ^∘(HAsc⁻, T), and the dissociation constants of ascorbic acid, K(T), were derived by the use of the Debye-Hückel equation for the activity coefficients and the Onsager and Quint and Viallard conductivity equations.     

铁矿粉化学热加工中亚铁含量的测定

提出了一种铁矿粉热加工生产工艺中亚铁含量测定的新方法。在氮气保护下，用盐酸溶出样中的亚铁，在硫磷混酸介质中以重铬酸钾标准溶液滴定，并对溶样条件进行了研究。该方法简单、快速、准确，已成功地应用于氧化催化法生产氧化铁中亚铁的控制分析和成品鉴定。     

Gas–liquid partition coefficients and Henry's law constants of methyl mercaptan in aqueous solutions of Fe(II)–CDTA chelate complex

Utilization of ferric chelate complex of trans-1,2-cyclohexanediaminetetraacetic acid (CDTA) for the oxidative scrubbing of H₂S and CH₃SH in Kraft mill streams can be beneficial from the standpoints of iron protection against precipitation and oxygen-mediated regenerative oxidation of the ferrous chelate CDTA. The physical solubility of methyl mercaptan in CDTA–Fe(III) complex cannot be measured directly because of oxidation of the sulfur-bearing gaseous species with the ferric chelate. Therefore, this investigation was carried out to determine the gas–liquid partition coefficients and Henry's law constants of methyl mercaptan in aqueous iron-free CDTA solutions and non-reacting ferrous chelate solutions (CDTA–Fe(II) complex), using the static headspace method with an estimated accuracy of about 2%. Experiments with aqueous solutions of chelate concentrations varying between 38 and 300 mol m⁻³ were carried out at temperatures between 298 and 333 K and atmospheric pressure. It was shown that the methyl mercaptan solubility decreases with increasing temperature for all systems but was not much influenced, in the studied conditions, by the chelate concentration especially at larger temperatures.     

自动电位滴定法标定硫酸铈溶液和测定硫酸亚铁片中铁含量

采用自动电位滴定法标定硫酸铈溶液,并进行硫酸亚铁片中铁含量的测定。自动电位滴定法以电位突跃监测终点,在45℃~50℃之间,以草酸钠溶液标定硫酸铈溶液,测定值的相对标准偏差(n=5)为0.070%。取硫酸亚铁片1片用0.01mol·L-1硫酸溶液30mL溶解,直接用硫酸铈溶液滴定测定铁含量。方法用于硫酸亚铁片样品分析,回收率为100%,测定值的相对标准偏差(n=5)在1.2%~2.6%之间。     

光纤过程检测硫酸亚铁缓释片释放度

建立光纤药物溶出度实时测定仪（FODT）在线监测硫酸亚铁溶出度测定的新方法.研究发现通过络合反应检测Fe2＋是可行的,FODT测定硫酸亚铁缓释片释放度与AAS测定结果无统计学意义.利用FODT过程检测硫酸亚铁缓释片释放度,全面直观地反映了药品的释放过程和内在质量,较经典方法能提供更多信息,测定过程简便自动,测定结果准确可靠.     

Morin transition suppression in Polycrystalline 57Hematite (α-Fe2O3) exposed to 56Fe(II)

We used the isotope selectivity of ⁵⁷Fe Mössbauer spectroscopy to investigate changes in the magnetic properties of polycrystalline hematite exposed to ferrous iron (Fe(II)). We found that sorption of ⁵⁶Fe(II), followed by interfacial electron exchange, alters the bulk magnetic properties of ⁵⁷hematite. After reaction with ⁵⁶Fe(II), we observed partial suppression of the Morin transition of ⁵⁷hematite to below 13 K. This is significantly lower than the Morin temperature (T _M) of ～230 K measured for isotopically enriched polycrystalline ⁵⁷hematite, as well as the T _M of 264?±?2 K reported for normal polycrystalline hematite.     

酒石酸亚铁分光光度法测定茶多酚

采用没食子酸丙酯为基准物质酒石酸亚铁作为显色剂，光度法测定茶多酚制品中茶多酚的含量。最大吸收波长５４０ｎｍ摩尔吸光系数２．６５×１０＾３回收率为９８％－１０１％，相对标准偏差为０．９０％。方法简便，结果令人满意。     

Porphyrin-cyclodextrin supramolecular complexes as myoglobin model in water

This mini-review reports supramolecular system composed of O-methylated β-cyclodextrins and metalloporphyrins that mimic the functions of myoglobin (Mb) in aqueous solution. Although many Mb functional models have been demonstrated so far, most models can bind dioxygen only in organic solvents such as toluene. Recently, we prepared the model systems composed of O-methylated β-cyclodextrin dimers having pyridine and imidazole linkers and tetrakis(4-sulfonatophenyl)porphinato iron(II) (hemoCD and Fe(II)PImCD). HemoCD binds dioxygen reversibly in aqueous solution, and the dioxygen adduct of hemoCD is very stable (a half-lifetime is 30 h at pH 7). Although the dioxygen affinity of Fe(II)PImCD is much higher than hemoCD, the stability and the reversibility of this system is lower. This review compares the functions of these model systems with those in biological systems. This review was written to dedicate to Professor Janos H. Fendler on the occasion of his 70th birthday. He gave me a chance to study biomimetic chemistry when he was a professor of Texas A&M University.     

8-羟基喹啉化学修饰壳聚糖亚铁配合物的合成及结构表征

为了利用高分子壳聚糖的生物特性降低药物的毒副作用,寻找理想的高分子药物载体,增加药物的生物特性,本文以高分子壳聚糖为载体,以8-羟基喹啉对其进行共价修饰,合成了喹啉类抗疟杀菌药的高分子药物前体,为增加其活性,与亚铁配位,合成了壳聚糖-8-羟基喹啉-亚铁配合物,用元素分析、TG-DTA分析、IR光谱、UV光谱和荧光光谱等研究了配合物的性质,并优化了配合物合成条件.结果表明,CTS-HQ对Fe²⁺离子的吸附等温线符合Langmuir吸附等温线方程,在室温下,pH=4时吸附8h的饱和吸附量Q_max=86.96mg/g,K=1.474J/mg.     

乳酸亚铁中总铁的溶样及比色测定

本文研究在ＨＮＯ３－ＨＣｌ体系乳酸亚铁中的Ｆｅ＾２＋会被氧化成Ｆｅ＾３＋，用碘基水杨酸比色法就能准确测定总铁量，回收率在９８％－１００％，相对标准偏差为１．１４％，摩尔吸光系数为５．６×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，含铁量在０－７００μｇ／１００ｍＬ范围内符合比耳定律。