Separation and determination of biphenyl nitrile compounds by microemulsion electrokinetic chromatography with mixed surfactants

A mixture of six biphenyl nitrile compounds and three related substances with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The microemulsion system contained 100 mM sodium dodecyl sulfate (SDS), 80 mM sodium cholate (SC), 0.81% v/v heptane, 7.5% v/v n-butanol, 10% v/v acetonitrile, and 10 mM borate. The addition of SC, organic modifiers, sample preparation, and temperature all showed remarkable effects on the separation. The capacity factor (k) was calculated by using dodecyl benzene as the marker for microemulsion, and the calculated partition coefficient log P(o/w) of the solutes was in the range of 3.35-7.38. The log k values matched well with the log P(o/w) with a correlation coefficient of 0.96. In addition, the linear correlation coefficients of each compound between peak area and concentration were from 0.996 to 0.998 with the repeatability RSD value < 1.2% for migration time and < 4.8% for peak area, and the highest theoretic plate number was > 586000. MEEKC was compared with micellar electrokinetic chromatography (MEKC) indicating that the former method is more suitable for this separation and can be used for the quality control of biphenyl nitrile compounds in the synthesis of liquid crystals.     

Separation of enantiomers in capillary electrophoresis with contactless conductivity detection

Contactless conductivity detection is successfully demonstrated for the enantiomeric separation of basic drugs and amino acids in capillary electrophoresis (CE). Derivatization of the compounds or the addition of a visualization agent as for indirect optical detection schemes were not needed. Non-charged chiral selectors were employed, hydroxypropylated cyclodextrin (CD) for the more lipophilic basic drugs and 18-crown-6-tetracarboxylic acid (18C6H4) for the amino acids. Acidic buffer solutions based on lactic or citric acid were used. The detection limits were determined as 0.3 microM for pseudoephedrine as an example of a basic drug and were in the range from 2.5 to 20 microM for the amino acids.     

金(Ⅲ)与某些中性氧配体(RnXO)形成的配合物及其表征

合成了金(Ⅲ)与七种中性氧配体RnXO(R=辛基或苯基;X=N,P,As和S;n=2,3)形成的十种配合物,可概括为两种类型:H(RnXO)x·AuCl_4·Sy(RnXO=TONO、TOPO、TPPO、DOSO、DPSO、TPAsO和bipyO_2;S=乙醇或水;x=1,2,3,y=0,1,2或3)和[Au(L)X_2](L=bipyO_2;X=Cl或Br)。用元素分析、摩尔电导、紫外和红外光谱、核磁共振和热重分析等方法测定了它们的组成和性质,并对其可能的结构也进行了讨论。     

High extraction ability of 1,3-dialkynyl calixarene towards mercury（Ⅱ） ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury(II)acetate could give mercury-containing alkynyl calixarenepolymer.The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury(II)ion was examined.When the moleratio of Hg~(2 )/calixarene was 1:1,the extractive percent can reach to 99.1%,and the extraction capacity was up to 431 mg/g.It couldalso decrease the Hg~(2 )concentration from 5 to 0.85 mg/L,which was only 17%of the national standard of effluent and satisfied thenational standard of drinking water.The extraction process included chemical reaction.     

Waterborne polyurethane assembly multifunctional coating for hydrophobic and antibacterial fabrics

Surface modification of fabrics is a powerful strategy that can endow fabrics with desired effects while keeping the intrinsic properties. Herein, an ordinary strategy, dipping-drying based layer-by-layer self-assembly (LbL) coating, is reported to functionalize fabrics’ surfaces. Firstly, the novel cation waterborne polyurethanes (QAHDPU) and anion waterborne polyurethanes (HDPU) are successfully designed and synthesized. By incorporating targeted molecule, hydantoin diol (HD) and quaternary ammonium salt with long alkyl chain (DOQA), the QAHDPU are antibacterial and hydrophobically functionalized. Taking advantage of strong adhesion, waterborne polyurethanes (WPUs) are physically bonded to surfaces of fabrics to generate durable antibacterial and hydrophobic fabrics. The QAHDPU with long alkyl chain combined with rough and porous fabric surface fabricates hydrophobic fabric surface, which can prevent bacteria from adhering to the fabrics. Furthermore, the coated fabrics present excellent antibacterial properties after chlorination, forming a second barrier against bacteria. The chlorinated coated fabrics, can inactivate 85.0–99.9% of Staphylococcus aureus and 85.0–97.7% of Escherichia coli with contact time of 60 min. The hydrophobic properties of coated fabrics are greatly improved with water contact angles of 122.0°–141.1°. In addition, the proposed method is applicable for a variety of fibers and expected to be used for industrial production.

Graphical abstract

     

纳米微晶Y_2Sn_(2-x)FexO_(7-δ)的制备及其催化选择性能研究

采用共沉淀并加法制备了Ｂ位掺杂烧绿石型稀土复合氧化物纳米微晶Ｙ２Ｓｎ２－ｘＦｅｘＯ７－δ（ｘ＝００～１０）。制备的纳米微晶属于立方晶系，Ｆｄ３ｍ，晶胞参数与掺杂量呈线性关系。通过Ｍｓｂａｕｅｒ、ＴＧＤＴＡ，气相色谱和γ射线辐照等技术研究了纳米微晶对ＣＯ的催化选择性能。结果表明，纳米微晶对ＣＯ的催化选择性明显高于一般粉料对ＣＯ的选择性；纳米微晶对ＣＯ的选择性与掺杂量有关；未辐照的纳米微晶，当掺杂量ｘ＝０６时，其对ＣＯ的选择性为最高，辐照后的纳米微晶，当掺杂量ｘ＝０４时，其对ＣＯ的选择性为最高     

Cellulose hydrolysis using zinc chloride as a solvent and catalyst

Cellulose gel with < 10% of crystallinity was prepared by treatment of microcrystalline cellulose, Avicel, with zinc chloride solution at a ratio of zinc chloride to cellulose from 1.5 to 18 (w/w). The presence of zinc ions in the cellulose gels enhanced the rate of hydrolysis and glucose yield. The evidence obtained from X-ray diffraction, iodine absorption experiments; and Nuclear Magnetic Resonance spectra analysis suggested the presence of zinc-cellulose complex after Avicel was treated with zinc chloride. Zinc-cellulose complex was more susceptible to hydrolysis than amorphous cellulose. Under the experimental condition, cellulose gels with zinc ions were hyrolyzed to glucose with 95% theoretical yield and a concentration of 14% (w/v) by cellulases within 20 h. The same gel was hydrolyzed by acid to glucose with 91.5% yield and a concentration of 13.4% (w/v).     

Oxidative Methyl Esterification of Primary Alcohols with Iodine‐Mediated Poly[4‐(Diacetoxyiodo)Styrene]

An operationally simple oxidative methyl esterification of primary alcohols in good yields using an iodine‐mediated poly[4‐(diacetoxyiodo)styrene] in methanol at room temperature is described. The polymeric reagent can be regenerated and reused as an environmentally benign reagent.     

A General, Highly Efficient Ullmann C-O Coupling Reaction under Microwave Irradiation and the Effects of Water

A general, rapid and highly efficient method for the synthesis of diaryl ethers under the assistance of microwave irradiation was described. A series of diaryl ethers were prepared by direct coupling of phenols and aryl halides in good to excellent yields in anhydrous DMF or NMP at 150 ℃ within 20 rain. The presence of water was found to have a significant impact on the Ullmann C-O coupling reaction between aryl halides and phenols under microwave irradiation.     

Determination of Osmium(VIII) by Flow Injection-Kinetic Methods Using Bromopyrogallol Red and Hydrogen Peroxide

A new flow injection-kinetic method has been developed for the determination of trace amount of osmium(WI), based on its catalytic effect on the bromopyrogallol red and hydrogen peroxide reaction. The reaction is followed spectrophotometrically by measuring the decrease in absorbance at 559 nm. The calibration graph for osmium(VIII) is linear over the range from 0.0040 to 0.10 μg/ml and the detection limit and sampling frequency are 0.0030 μg/ml and 47 per hour, respectively. The proposed method was applied to the determination of trace amounts of osmium in refined ores and chlorination residues with satisfactory results.