编者的话

本刊自1952年7月出版以来,由于读者的关心爱护,投稿的踊跃,每月收入的稿件,一向是很多的。尤其是近几个月来,收到的稿件每月多至一二百篇,但选用的则只是寥寥几篇,大部分的稿件都需要退远,长此下去,浪费了投稿同志的时间和精力,我们很是抱歉,仔细地检查一下,造成这种情况的原因,一部分固然是由于稿件的内容,另一部分是由于征稿的办法计划的不够周密,究竟最切实用是什么样的稿,或稿件的时间期性是怎样,都没     

ICP–AES法测定超高强度钢中的Al,Mn,Si,Ti

建立ICP–AES法测定超高强度钢中Al,Mn,Si,Ti 4种杂质元素的分析方法。研究了溶解条件试验及共存元素对4种分析元素的光谱干扰的情况,选择了Al 394.401 nm,Mn 257.610 nm,Si 251.611 nm,Ti 334.941 nm作为分析谱线。在选定的实验条件下,Al,Mn,Si,Ti的含量在0.001%~0.2%的范围内有良好的线性关系,相关系数均大于0.993,Al,Mn,Si,Ti的检出限为0.000 1~0.003 5 mg/L,加标回收率为94%~120%,测定结果的相对标准偏差小于10%(n=8)。该方法准确、快速,可用于超高强度钢中Al,Mn,Si,Ti的含量测定。     

微波辅助消解-电感耦合等离子体原子发射光谱法(ICP-AES)测定几种血藤中17种元素

建立电感耦合等离子体原子发射光谱法(ICP-AES)测定血藤类中药中K,Ca,Mg,P,Sr,Fe,Mn,Zn,Cu,Co,Cr,Al,Ba,Ni,As,Pb和Cd 17种常量和微量元素含量的分析方法。样品用微波辅助消解,ICP-AES法检测几种血藤中17种元素的含量,方法的检出限为0.000 03~0.009 81μg/mL,加标回收率88.37%~110.00%,相对标准偏差(RSD)均小于5.0%,方法可快速、灵敏、准确测定血藤类中药中多种常量、微量元素的含量。血藤样品中除含有人体必需的常量元素K,Ca,Mg外,还含有Fe,Zn,Mn,Cr,Co等必需的微量元素和其它元素P,Ni,Ba,Al,Sr,Pb,Cd,Ba等。     

心宝丸中11种微量、宏量元素的测定分析

采用火焰原子吸收分光光度法测定了心宝丸中钠,钾,钙,镁,铁,铬,锰,镍,镉,铜,锌１１种微,宏量元素的含量。结果表明,心宝丸中含有丰富的微量,宏量元素。为探讨中成药中微量,宏量元素与治疗冠心病的关系提供了有用的数据。     

提纯硫酸的方法

1958年是我国工农业生产大跃进的一年。在这一年里,我国工业农业得到了空前的大发展,特别是钢铁工业,更是一日千里的向前跃进,因此象钢铁分析,电池工业,半导体制造,制药工业等部门,对于纯硫酸的需要量日增,而目前的产量还不能满足各方面日益增长的需要,为了解决这个问题,就必须走党提出来的,土洋结合,全民办工业的路线。下面,我们介绍一下提纯硫酸的方法,步骤和原理。     

电导滴定

溶液电导的测定,可用来做酸碱滴定或沉淀滴定,以计算溶液的浓度。如在强碱溶液中,慢慢滴入强酸溶液,则OH~-渐渐减少,电导亦随之减少,至电导减至最小时,即表示OH~-已完全中和,再多加一滴酸则因H~+的生成又使电导加大。这样,假若我们在一定量的碱溶液内,慢慢的滴入酸溶液,在滴定的过程中,随时测定溶液的电导,将结果作图,用所加入的酸溶液的体积为横标,比电导为纵标,当得两个直线,这两个直线的交点,就是中和点。在实际做物理化学实验时,我们是用威斯登电桥,求溶液的电阻的,所以我们只须用威斯登电桥上的数为纵标作图即可。我们知道,为了避免电解作用或极化作用的发生,我们测电导时的电源一定要用交流电,而且因为我们要用耳机听音去找平衡点,所以     

X射线荧光光谱法测定灰岩中14种主次量元素

采用X射线荧光光谱法对灰岩中的Ca,Mg,Si,K,Na,Fe,Al,Ti,P,S,Mn,Sr,Ba,Cl等14种元素进行同时测定,采用硼酸镶边垫底的粉末压样法,优化了测量条件。对比较轻的元素,采用经验影响系数法校正基体效应,对于较重的元素,采用理论α影响系数法校正基体效应。分析标准参考物质GBW 07132,各元素的精密度(RSD)为0.1%~5.9%,分析标准参考物质GBW 07130,各元素的测定值与标准值相符,该方法对各元素的测定范围宽、速度快。     

从各种途径,培养学生学习化学的兴趣,提高学生的智能

我校已办了三届化工职业班,招生时学生的各科入学成绩都较低,一般同学的素质较差。当然化学成绩也不好,而我校的化工职业班的性质决定了对化学教学的要求较高,根据江苏省教育厅对化工类职业中学的统一要求,我校开设的与化学有关的课程,有中学化学,有机化学,化工分析基础,化工原理,化工基础,化工仪表,化工机械等。由于多方面的原因,我们要完成这样的教学任务的确很艰巨。怎样培养学生学习化学的兴趣,怎样提高学生的知识和能力,以适应将     

改性硝酸铵自敏化结构特征

对经复合表面活性剂处理的改性硝酸铵及普通硝酸铵晶体进行电镜扫描,孔径孔容分布,粒径分布,比表面积测定,抗吸湿结块性,差示量热分析以及爆炸性能的实验研究,结果表明,与普通硝酸铵相比,改性硝酸铵的晶形歧化,比表面积大,富含气孔,大部分的有效孔径座落在介孔范围,有较好的粒度级配,晶变热降低,且晶变点后移,具备自敏化结构特征,并且有良好的抗吸湿结块性,用它代替普通硝酸铵所制得的粉状工业炸药具有良好的物理性能和爆炸性能。     

植物样中氮磷铁硼等十六个元素的测定

报道了植物样品经Ｈ２ＳＯ４＋ＨＳ２Ｏ凯氏法消煮处理,试液分别用蒸馏法测氮,用ＩＣＰ－ＡＥＳ法测定的钠,钙,钾,镁,铁,磷,锶,钛,锰,锌,硼,铜,锂钒,镍常量及痕量元素的分析方法。此法一次溶样,多元素测定,快速,简便,可靠。植物档样的分析结果与标准值的相对误差符合要求。     

Application of a UPLC‐MS/MS method for the analysis of alosetron in human plasma to support a bioequivalence study in healthy males and females

A simple, rapid and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed and validated for the determination of alosetron (ALO) in human plasma. The assay method involved solid‐phase extraction of ALO and ALO 13C‐d3 as internal standard (IS) on a LichroSep DVB‐HL (30 mg, 1 cm³) cartridge. The chromatography was performed on an Acquity UPLC BEH C₁₈ (50 × 2.1 mm, 1.7 µm) column using acetonitrile and 2.0 mm ammonium formate, pH 3.0 adjusted with 0.1% formic acid (80:20, v/v) as the mobile phase in an isocratic mode. For quantitative analysis, the multiple reaction monitoring transitions studied were m/z 295.1/201.0 for ALO and m/z 299.1/205.1 for IS in the positive ionization mode. The method was validated over a concentration range of 0.01–10.0 ng/mL for ALO. Post‐column infusion experiment showed no positive or negative peaks in the elution range of the analyte and IS after injection of extracted blank plasma. The extent of ion‐suppression/enhancement, expressed as IS‐normalized matrix factor, varied from 0.96 to 1.04. The assay recovery was within 97–103% for ALO and IS. The method was successfully applied to support a bioequivalence study of 1.0 mg alosetron tablets in 28 healthy Indian male and female subjects. Copyright © 2015 John Wiley & Sons, Ltd.     

Enhanced macrophage polarization induced by COX-2 inhibitor-loaded Pd octahedral nanozymes for treatment of atherosclerosis

Inhibition of foam cell formation is considered a promising treatment method for atherosclerosis, the leading cause of cardiovascular diseases worldwide. However, currently available therapeutic strategies have shown unsatisfactory clinical outcomes. Thus, herein, we design aloperine (ALO)-loaded and hyaluronic acid (HA)-modified palladium (Pd) octahedral nanozymes (Pd@HA/ALO) that can synergistically scavenge reactive oxygen species (ROS) and downregulate cyclooxygenase-2 (COX-2) expression to induce macrophage polarization, thus inhibiting foam cell formation to attenuate atherosclerosis. Due to the targeted effect of HA on stabilin-2 and CD44, which are overexpressed in atherosclerotic plaques, Pd@HA/ALO can actively accumulate in atherosclerotic plaques. Subsequently, the antioxidative effects of Pd octahedral nanozymes are mediated by their intrinsic superoxide dismutase- and catalase-like activities capable of effective scavenging of ROS. In addition, anti-inflammatory effects are mediated by controlled, on-demand near-infrared-triggered ALO release leading to inhibition of COX-2 expression. Importantly, the combined therapy can promote the polarization of macrophages to the M2 subtype by upregulating Arg-1 and CD206 expression and downregulating expression of TNF-α, IL-1β and IL-6, thereby inhibiting atherosclerosis-related foam cell formation. In conclusion, the presented in vitro and in vivo data demonstrate that Pd@HA/ALO enhanced macrophage polarization to reduce plaque formation, identifying an attractive treatment strategy for cardiovascular disease.     

Ultra-sensitive detection of bacterial toxin with silicon nanowire transistor

Nanowire field effect transistors (nano-FET) were lithographically fabricated using 50 nm doped polysilicon nanowires attached to two small gold terminals separated from each other by a approximately 150 nm gap to serve as the basis for electronic detection of bacteria toxins. The device characterizations, semiconducting properties and use in a robust and sensitive bio-molecular detection sensor of bacterial toxins were reported in this work. The device characteristics were demonstrated with varying gate and drain voltages. The bio-molecular detection was demonstrated using electrochemical impedance spectroscopy (EIS), using Staphylococcus aureus Enterotoxin B (SEB) as the target molecule. The detection limit of SEB was observed in the range of 10-35 fM.     

质膜微囊的分离及原子力显微镜研究

采用非去污剂在OptiPrep梯度中漂浮超声处理质膜的方法, 从鼠肺中分离质膜微囊, 在原子力显微镜下以不同条件进行了观察. 该非去污剂法能分离出完整的质膜微囊, 在去离子水稀释500倍的条件下得到了清晰的质膜微囊的原子力显微镜图片, 建立了一种新的快速分离完整质膜微囊的方法和用原子力显微镜观测质膜微囊结构的新方法.     

Liquid chromatography with tandem mass spectrometry method for trace level analysis of migrated secondary alkanesulfonate from poly(tetramethylene terephthalate) into food simulants

Secondary alkanesulfonate has been widely used as an antistatic additive in polymers for producing anti‐dust food packaging containers. Currently, no reported method exists for accurate quantification of secondary alkanesulfonate in ethanolic and acidic food simulants. A new liquid chromatography with tandem mass spectrometry method was developed to quantify the migrated amount of secondary alkanesulfonate at trace levels in food simulants from a poly(tetramethylene terephthalate) containing secondary alkanesulfonate. The poly(tetramethylene terephthalate) samples loaded with the antistatic additive were exposed to various food simulants. The collected extracts were directly analyzed by liquid chromatography with tandem mass spectrometry in electrospray ionization negative mode. As secondary alkanesulfonate is a mixture containing C14 to C17 chain lengths, it was separated on a Poroshell 120 EC‐C8 column adopting methanol water gradient program. The migration of secondary alkanesulfonate ranged from 58 to 329 ppb; which is well within the allowed permissible regulatory limits and the adopted method was validated by conducting spiking studies and acceptable recoveries were obtained. The developed method was not only sensitive to detect lower levels of the migrated antistatic additive, but it also avoided more cumbersome sample preparation methodologies like sample enrichment and other derivatization approaches.     

(S)-4-(4-aminobenzyl)-2-oxazolidinone based 2-azetidinones for antimicrobial application and luminescent sensing of divalent metal cations

The impact of linezolid as an antibiotic against gram-positive bacteria has inspired synthetic chemists to use oxazolidinones as substrate molecule in the synthesis of newer scaffolds with important pharmacological implication. The oxazolidin-2-ones are key intermediates in the synthesis of many interesting biologically active compounds. Design and synthesis of a new series of (S)-4-(4-aminobenzyl)-2-oxazolidinone based multifunctional azetidinones were accomplished. Synthesis of the scaffolds was performed through a multi-step reaction process involving protection of amine functional group, conversion of protected (S)-4-(4-aminobenzyl)-2-oxazolidinone to its acetic acid derivative and then to acid chloride, and finally coupled with different substituted aromatic imines under mild reaction conditions in presence of an appropriate base. Structural characterization was carried out using conventional spectroscopic techniques. The compounds were screened for their antimicrobial activity against gram-positive and gram-negative bacteria and were found to possess better and promising antimicrobial property than some of the reported antimicrobial drugs like disulfonamide and tetracycline. Additionally, the scaffolds also exhibit prominent sensing property for divalent metal cations like Cu²⁺, Zn²⁺, and Ni²⁺, through fluorescence quenching effect.     

Palladium polyether diphosphinite complex anchored in polyethylene glycol as an efficient homogeneous recyclable catalyst for the Heck reactions

Palladium polyether diphosphinite complex anchored on polyethylene glycol is reported as an efficient catalyst for Heck coupling reactions. The catalyst is soluble in the solvent with reactants and products during reaction and can be separated from reaction media in biphasic form by the addition of anti-solvent like n-hexane and further recycled. The developed methodology offers mild reaction condition, short reaction time with an excellent recyclability of the catalyst. Aryl iodides as well as aryl bromides are well tolerated giving excellent yields.     

High-performance capillary electrophoresis to determine intact keratan sulfate and hyaluronic acid in animal origin chondroitin sulfate samples and food supplements

Chondroitin sulfate is extracted from animal cartilaginous tissues and is commercialized as active principle against osteoarthritis. Its biological activity depends on its purity grade and could be altered by the presence of other glycosaminoglycans like keratan sulfate that could be contemporarily extracted from animal tissues or like hyaluronic acid that, instead, is added on purpose in food supplements. Although numerous methods are reported in literature for quality control analyses of chondroitin sulfate, few of them are able to detect other glycosaminoglycans. In this paper, for the first time, a new high-performance CE method was set up to quantify the chondroitin sulfate, the eventual keratan sulfate, and hyaluronic acid as intact chains: five chondroitin sulfate standards and 13 animal origin samples or food supplements from six different suppliers were analyzed. The new method was able to determine keratan sulfate similarly to a previously reported high-performance anion-exchange chromatography method, but in addition it showed the advantage to determine also the hyaluronic acid as never reported before.     

Enzymatic Polymerization of Natural Anacardic Acid and Antibiofouling Effects of Polyanacardic Acid Coatings

Anacardic acid, separated from cashew nut shell liquid, is well known for its strong antibiotic and antioxidant activities. Recent findings indicate that phenolic compounds from plant sources have an effect on Gram-negative bacteria biofilm formation. In this work, a polyphenolic coating was prepared from anacardic acid using enzymatic synthesis and tested for its effects on biofilm formation of both Gram-negative and Gram-positive bacteria. Natural anacardic acid was enzymatically polymerized using soybean peroxidase. Hydrogen peroxide and phenothiazine-10-propionic acid were used as an oxidizing agent and redox mediator, respectively. Nuclear magnetic resonance and Fourier transform infrared (FTIR) analyses showed the formation of oxyphenylene and phenylene units through the phenol rings. No linkage through the alkyl chain was observed, which proved a high chemo-selectivity of the enzyme. Aqueous solvents turned out to play an important role in the polymer production yield and molecular weight. With 2-propanol, the highest production yield (61%) of polymer (molecular weight = 3,900) was observed, and with methanol, higher-molecular-weight polymers (5,000) were produced with lower production yields (43%). The resulting polyanacardic acid was cross-linked on a solid surface to form a permanent natural polymer coating. The FTIR analysis indicates that the cross-linking between the polymers took place through the unsaturated alkyl side chains. The polyanacardic acid coating was then tested for its antibiofouling effect against Gram-negative and Gram-positive bacteria and compared with the antibiofouling effects of polycardanol coatings reported in the literature. The polyanacardic acid coating showed more reduction in biofilm formation on its surface than polycardanol coatings in the case of Gram-positive bacteria, while in the case of Gram-negative bacteria, it showed a similar reduction in biofilm formation as polycardanol.     

A lysozyme and magnetic bead based method of separating intact bacteria

As a response to environmental stress, bacterial cells can enter a physiological state called viable but noncultivable (VBNC). In this state, bacteria fail to grow on routine bacteriological media. Consequently, standard methods of contamination detection based on bacteria cultivation fail. Although they are not growing, the cells are still alive and are able to reactivate their metabolism. The VBNC state and low bacterial densities are big challenges for cultivation-based pathogen detection in drinking water and the food industry, for example. In this context, a new molecular-biological separation method for bacteria using point-mutated lysozymes immobilised on magnetic beads for separating bacteria is described. The immobilised mutated lysozymes on magnetic beads serve as bait for the specific capture of bacteria from complex matrices or water due to their remaining affinity for bacterial cell wall components. Beads with bacteria can be separated using magnetic racks. To avoid bacterial cell lysis by the lysozymes, the protein was mutated at amino acid position 35, leading to the exchange of the catalytic glutamate for alanine (LysE35A) and glutamine (LysE35Q). As proved by turbidity assay with reference bacteria, the muramidase activity was knocked out. The mutated constructs were expressed by the yeast Pichia pastoris and secreted into expression medium. Protein enrichment and purification were carried out by SO₃-functionalised nanoscale cationic exchanger particles. For a proof of principle, the proteins were biotinylated and immobilised on streptavidin-functionalised, fluorescence dye-labelled magnetic beads. These constructs were used for the successful capture of Syto9-marked Microccocus luteus cells from cell suspension, as visualised by fluorescence microscopy, which confirmed the success of the strategy.