火焰原子吸收光谱法测定血浆代用品中钾和钠

本文报道了火争原子吸收光谱法测定血浆代用品中钾，钠，使用镧和氯化铯，消除了电离干扰和共存元素干扰，本法简便，快速，本法的准确度和精密度均令人满意。     

Interaction parameters and (solid + liquid) equilibria calculation for KCl–H2O–HCl–C2H5OH,K2SO4–H2O–H2SO4 and K2SO4–H2O–C2H5OH mixed solvent-electrolyte systems

This work deals with the prediction and experimental measurements of the (solid + liquid) equilibrium (SLE) in acid medium for industrial purposes. Specific systems including KCl–ethanol–water–HCl and K₂SO₄–water–H₂SO₄ were analyzed. At first, a critical discussion of SLE calculations was given, based on the well-known UNIQUAC extended and LIQUAC models. Two new proposals were derived, considering the explicit necessity of a new reference state for SLE calculations for the studied (solvents + acid) mixtures. The solubility of KCl in water–ethanol–HCl mixed solvents was measured in the temperature range of 300.15 to 315.15 K using an analytical gravimetric method. These results combined with some other experimental data reported in the open literature let us to propose a set of parameters for the new models. They included the interaction parameters between ethanol and the H⁺ ion. The prediction capability of the new models, for calculations in acid medium, was illustrated. Experimentally, it was observed that the (K₂SO₄ + water + H₂SO₄) system presented the unusual behavior of increasing K₂SO₄ solubility with an increase in the sulfuric acid concentration. This was accurately predicted by the newly proposed models.     

Sulfonyl Ketenimines as Key Intermediates in One‐Pot Synthesis of N‐Sulfonyl‐2‐alkaneimidoyl Selenocyanates

Sulfonyl‐ketenimine intermediates, generated by the addition of Cu acetylides to sulfonyl azides, are trapped by KSeCN to afford N‐sulfonyl‐2‐alkaneimidoyl selenocyanates in moderate‐to‐good yields.     

基于DNA酶催化增敏的微流控顺序注射化学发光法检测钾离子的研究

基于G-四联体/血红素形成的DNA酶催化增敏鲁米诺-H2O2发光反应原理,建立了微流控顺序注射化学发光检测K+的新方法。在K+的促进作用下,富含鸟嘌呤的寡核苷酸PS5.M折叠成G-四联体,并对血红素表现出较高的亲合力,形成DNA酶,显著地增强血红素的类辣根过氧化物酶活性,催化鲁米诺-H2O2化学发光反应。在优化的实验条件下,化学发光检测K+的线性范围为1.0~700μmol·L-1,检出限为0.54μmol·L-1,用100μmol·L-1的K+形成的DNA酶连续测定10次,相对标准偏差(RSD)为1.61%。常见的碱金属和碱土金属离子均无显著干扰。该方法可用于真实水样中K+的分析,测定结果与原子吸收法一致。     

原子荧光光谱法测定萤石中的微量铅

以铁氰化钾–盐酸羟胺体系代替铁氰化钾–草酸体系,建立原子荧光法测定萤石中铅含量的方法。对实验条件进行了优化,在负高压280 V,灯电流65 m A,原子化高度8 mm,还原剂3%硼氢化钾溶液(含0.5%Na OH),载流4%盐酸的工作条件下,铁氰化钾–盐酸羟胺体系有明显的增感作用。样品中Ca~(2+)含量在4 g/L之内不影响铅的测定,溶解阶段通过高氯酸冒烟赶尽HF排除氟离子的干扰,并加入硫氰酸钠–邻菲罗啉消除铁和铜等离子的干扰。测定铅的线性范围为0~80 ng/L,相关系数r=0.999 6,方法检出限为0.187μg/L,测定结果的相对标准偏差为0.25%~1.40%(n=12),加标回收率为97.8%~104.5%。该方法测定结果与电感耦合等离子体原子发射光谱法测定结果相符。原子荧光光谱法快速准确,基体干扰少,灵敏度高。     

Environmentally friendly homocoupling reaction of functionalized potassium aryl trifluoroborates salts in aqueous media

The homocoupling reaction between potassium aryl trifluoroborates containing different functionalities promoted by a catalytic amount of Pd(OAc)₂ is described. The methodology uses water as a solvent under aerobic conditions to give the corresponding biaryl compounds in good yields.     

Structure and Thermal Properties of Lithium Cyanate

The synthesis, structural, and thermal characterization of lithium cyanate are reported in this work. LiOCN forms crystals in the trigonal crystal system. The structure was solved in the space group R$\bar{3}$ m. It is isomorphous to the structure of sodium cyanate. In the temperature range from –90 °C up to the melting point no phase transition was observed. Furthermore the vibrational Raman spectrum was measured. The system KOCN‐LiOCN shows a dystecticum and the new phase was confirmed by powder X‐ray diffraction.     

同时测定血清中4种电解质的流动注射微电极串联电化学自动分析系统

基于流动注射-微电极串联的动态电化学技术,建立了能快速、自动、同时测定血清中K(+),Na(+),Cl(-)和Ca(2+)的分析方法和系统,并成功用于血清样品的测定.为稳定4种电极的基线电位、加快电极响应速度,优化了载流的组分:23mmol/L Na2B4O7-H3BO3(pH 7.40),0.25mmol/L K(+...     

The effect of boric acid on the vapour liquid equilibrium of aqueous potassium carbonate

Aqueous potassium carbonate has seen renewed interest as a viable solvent for pre and post combustion carbon capture and storage. However, slow reaction kinetics may require the addition of a rate promoter such as boric acid to improve efficiency. The vapour liquid equilibrium of 30 weight percent potassium carbonate with 0, 3 and 5 weight percent boric acid was investigated at 50 and 70 °C using a dynamic inert gas stripping method. By estimating the boric acid reactions an Electrolyte-NRTL model was able to fit this data and literature results very closely.     

One-pot approach for the synthesis of 2-aryl benzothiazoles via a two-component coupling of gem-dibromomethylarenes and o-aminothiophenols

One-pot synthesis of 2-aryl benzothiazoles from gem-dibromomethylarenes using 2-aminoarylthiols is described. Benzothiazoles were obtained in high chemical yields under mild conditions. This transformation would facilitate synthesis by short reaction times, large-scale synthesis, easy and quick isolation of the products, which are the main advantages of this procedure.