A method for preparation of magnetizable cellulose and its application in radioimmunoassays for T3 and T 4 1

An easy adoptable technique has been developed to prepare magnetizable cellulose by the process of wet grinding of a mixture of iron oxide (magnetite) and cellulose in a stirred ball mill. Anti rabbit IgG was covalently coupled to this magnetizable cellulose. The immunosorbent thus prepared has been used in radioimmunoassays of T₃ and T₄ for the separation of bound and free antigens. The reliability of the above immunosorbent has been validated by studying assay parameters such as non-specific binding (NSB), maximum binding (B ₀), CV etc. The single step process of wet grinding adopted here not only firmly binds magnetite and cellulose physically, but also lowers the size of the resulting magnetizable cellulose. The conventional method of preparation involves the coprecipitation of cellulose dissolved in cuprammonium hydroxide solution along with iron oxide, followed by extensive grinding and sieving of the iron oxide impregnated cellulose.     

A New Method of Surface Preparation for High Spatial Resolution EPMA/SEM with an Argon Ion Beam

A novel specimen preparation method has been devised utilizing an Ar ion beam with a masking plate and an apparatus for this method has been developed for the preparation of good quality cross sections for high spatial resolution microscopy and microanalysis. This apparatus is defined as a Cross-section Polisher. The method overcomes most of the drawbacks inherent in the traditional method of mechanical grinding and polishing and enabled us to prepare good quality cross sections with much larger areas than those prepared by a focused ion beam method, essentially retaining the excellent characteristics of the latter method. Microstructural observations of corrosion morphology and chemical analysis of corrosion products in a corrosion-resistant alloy (Alloy 825) with a thermal field emission type electron probe X-ray microanalyzer are reported to show the power of the Cross-section Polisher.     

Cellulose sulphuric acid as a biodegradable and reusable catalyst for the Knoevenagel condensation

A green, mild and efficient method for Knoevenagel condensation of 3-formylchromone/2-chlroquinoline-3-carbaldehyde with active methylene compounds such as Meldrum’s acid/ethyl cyanoacetate using biosupported cellulose sulphuric acid (CSA) in the solid-state by grinding under solvent-free condition has been developed. This method provides several advantages including environmental friendliness, shor t reaction times, high yields and a simple work-up procedure. Moreover, the CSA was successfully reused for four cycles without significant loss of activity.     

某矿山金矿石样品加工及分析方法优化研究

某矿山金矿石样品中存在中粗颗粒金,颗粒金的存在将对分析样品的均匀性和代表性产生影响。通过棒磨、密封粉碎及盘磨等方式研究,选择出最优的样品加工方式,同时通过分析方法比对,选择出最优的样品分析方法。实验确定金矿石采用圆盘细碎机加工至样品粒度不大于0.074 mm,混匀后即获得分析试样。分析试样经王水消解后采用泡沫吸附进行富集,火焰原子吸收光谱法测定。通过研究,取得最优的金矿样品加工和分析方案,为某矿山提供了高品质的金储量评估数据。     

Tire-Rubber-Waste Recycling and Active Powder of Discretely Devulcanized Rubber

Key aspects of tire-rubber-waste collection, accumulation, processing, and further application have been examined. Special attention has been paid to application of ground tire rubber as a road-pavement modifier. The data on the structure and properties of tire-rubber powders obtained by different grinding techniques have been presented. It has been established that active tire-rubber powder (APDDR) fabricated by means of high-temperature shear grinding exhibits substantial advantages as compared to other rubber powders. In particular, applying these powders as modifiers has allowed to significantly improve properties of the paving bitumen and, as a result, the quality of asphalt concrete.     

Small‐Sized Tungsten Nitride Particles Strongly Anchored on Carbon Nanotubes and their Use as Supports for Pt for Methanol Electro‐oxidation

The anchoring of small‐sized WN (tungsten nitride) nanoparticles (NPs) with good dispersion on carbon nanotubes (CNTs) offers an effective means of obtaining promising materials for use in electrocatalysis. Herein, an effective method based on grinding treatment followed by a nitridation process is proposed to realize this goal. In the synthesis, a solution containing H₄[SiO₄(W₃O₉)₄] (SiW₁₂) and CNTs modified with polyethylenimine (PEI‐CNTs) was ground to dryness. Small‐sized WN NPs were anchored onto the CNTs with good dispersion after calcination under NH₃. Under hydrothermal assembly conditions (absence of grinding), WN particles of larger size and with inferior dispersion were obtained, demonstrating the important role of the grinding process. The benefit of the small‐sized WN has been demonstrated by using WN/CNTs as a support for Pt to catalyze the methanol electro‐oxidation reaction. The mass activity of Pt‐WN/CNTs‐G‐70 (where G denotes the grinding treatment, and 70 is the loading amount (%) of WN in the WN/CNTs) was evaluated as about 817 mA mg^?1_Pt, better that those of commercial Pt/C (340 mA mg^?1_Pt) and Pt/CNTs (162 mA mg^?1_Pt). The Pt‐WN/CNTs‐G also displayed good CO tolerance. In contrast, Pt‐WN/CNTs prepared without the grinding process displayed an activity of 344 mA mg^?1_Pt, verifying the key role of grinding treatment in the preparation of WN/CNTs with good co‐catalytic effect.     

A novel catalyst-free mechanochemical protocol for the synthesis of 2,3-dihydro-1H-perimidines

A rapid, efficient, and green grinding assisted method for the synthesis of 2,3-dihydro-1H-perimidines has been developed. 1,8-Diaminonaphthalene and aldehydes were ground using mortar and pestle for 5 minutes affording the product in moderate to excellent yields. The methodology minimises the use of conventional workup and column chromatographic techniques.     

研磨法在固相有机合成中的应用

近几十年来有机工作者将研磨法用于固态有机合成, 取得了一些成效, 综述了近年来典型的固相有机研磨反应.     

Aqueous mortar–pestle grinding: An efficient,attractive, and viable technique for the regioselective synthesis of β-amino alcohols

A green and highly regioselective approach for the synthesis of β-amino alcohols (with yields from 15 to 98%) via the aminolysis of epoxides by varied amines using LiBr under aqueous mortar–pestle grinding conditions has been described. Use of a mild catalyst, ordinary grinding, time economy, cost effectiveness, complete regioselectivity, and a very good to excellent yield of desired products makes this process an attractive route for the synthesis of biologically significant pharmacophores. Furthermore, the developed protocol has been successfully extended to the synthesis of novel series of β-amino alcohols (3r–ad) bearing benzofused 1,2,3-triazole heterocycle with complete regioselectivity. The structure of the synthesized molecules has been characterized by spectroscopic techniques such as ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and mass spectroscopy/elemental analysis.     

Calcinized eggshell: an environmentally benign green catalyst for synthesis of 2-arylbenzothiazole derivatives

The calcinized eggshell as an efficient and green catalyst has been prepared from chicken eggshell waste and is characterized by different analytical techniques such as FT-IR, XRD, TGA, SEM, and EDAX. A series of substituted 2-arylbenzothiazoles have been synthesized by reaction of o-aminothiophenol and aromatic aldehydes under solvent free conditions using a grinding method at room temperature. The reaction proceeds smoothly in excellent yields (86–97 %), short reaction time (15–48 min), and with an easy work-up procedure. The reuse of catalyst and purification of products by non-chromatographic methods are some additional features of the present protocol. The calcinized eggshell is a safe, inexpensive, and a green catalyst with high catalytic efficiency obtained from renewable resources.     

A solvent-free synthesis of 1-(4-chlorophenyl)pyrazolidin-3-one in a ball mill

An easy, solvent-free method for the synthesis of 1-(4-chlorophenyl)pyrazolidin-3-one has been achieved by grinding 4-chlorophenyl hydrazine and methyl acrylate in the presence of base in a ball mill. A systematic investigation of the reaction has been made in order to study the various factors affecting the reaction.     

Efficient NaOH-Catalyzed Reaction of Aromatic Aldehyde,Cyclic Ketones,and Malononitrile Under Solvent-Free Conditions Using a Grinding Method

An efficient and facile synthesis of 2,6-dicyanoanilines via a one-pot reaction of aromatic aldehydes, malononitrile, and cyclic ketones in the presence of NaOH under solvent-free conditions using a grinding method has been developed. Compared with the classical reaction conditions, the new synthetic method has the advantages of excellent yields, shorter reaction times, and mild reaction conditions.     

An efficient synthesis of pyrazole chalcones under solvent free conditions at room temperature

An easy,safe,solvent free and effective method for the synthesis of pyrazole-substituted chalcones has been achieved by grinding pyrazole aldehydes and acetophenones in the presence of activated barium hydroxide(C-200) in high yield within short span of time.All reactions were carried out just by grinding the two reactants in the presence of activated barium hydroxide(C-200). Results are also compared with sodium hydroxide and potassium hydroxide.     

Evaluation of grinding methods for pellets preparation aiming at the analysis of plant materials by laser induced breakdown spectrometry

It has been demonstrated that laser induced breakdown spectrometry (LIBS) can be used as an alternative method for the determination of macro (P, K, Ca, Mg) and micronutrients (B, Fe, Cu, Mn, Zn) in pellets of plant materials. However, information is required regarding the sample preparation for plant analysis by LIBS. In this work, methods involving cryogenic grinding and planetary ball milling were evaluated for leaves comminution before pellets preparation. The particle sizes were associated to chemical sample properties such as fiber and cellulose contents, as well as to pellets porosity and density. The pellets were ablated at 30 different sites by applying 25 laser pulses per site (Nd:YAG@1064 nm, 5 ns, 10 Hz, 25 J cm⁻²). The plasma emission collected by lenses was directed through an optical fiber towards a high resolution echelle spectrometer equipped with an ICCD. Delay time and integration time gate were fixed at 2.0 and 4.5 μs, respectively. Experiments carried out with pellets of sugarcane, orange tree and soy leaves showed a significant effect of the plant species for choosing the most appropriate grinding conditions. By using ball milling with agate materials, 20 min grinding for orange tree and soy, and 60 min for sugarcane leaves led to particle size distributions generally lower than 75 μm. Cryogenic grinding yielded similar particle size distributions after 10 min for orange tree, 20 min for soy and 30 min for sugarcane leaves. There was up to 50% emission signal enhancement on LIBS measurements for most elements by improving particle size distribution and consequently the pellet porosity.     

Rapid new methods for the determination of nitrogen in fertilisers and other compounds : Automatic analysis

The determination of ammonia nitrogen, or the sum of nitrate and ammonia nitrogen in fertilisers as described in a previous article, has been automated. In routine work one operator can analyse 50 samples (including grinding, weighing, distillation and titration) within one hour; the total time of analysis per sample does not exceed 3.5 min.     

A new recyclable ditribromide reagent for efficient bromination under solvent free condition

1,2-Dipyridiniumditribromide-ethane (DPTBE) has been synthesized and explored as a new efficient brominating agent. The crystalline ditribromide reagent is stable for months and acts as a safe source of bromine requiring just 0.5 equiv for complete bromination. It has high active bromine content per molecule and shows a remarkable reactivity compared to other tribromide reagents toward various substrates by just grinding the reagent and substrates in a porcelain mortar at room temperature. No organic solvent has been used during any stage of the reaction for substrates giving product as solid. Product can easily be isolated by just washing the highly water soluble 1,2-dipyridiniumdibromide-ethane (DPDBE) from the brominated product. The spent reagent can be recovered, regenerated, and reused without any significant loss.     

机械研磨时间对铜基甲醇合成催化剂性能的影响

采用机械研磨燃烧法在不同研磨时间下制备了系列Cu/ZnO/Al2O3催化剂,并评价了其在一氧化碳加氢制备甲醇反应中的活性。催化剂前驱体的焙烧过程通过热重-差热分析仪(TG-DSC)监测。采用X射线衍射(XRD)、扫描电镜(SEM)、N2吸附、程序升温还原(TPR)和N2O氧化后氢气滴定等方法对催化剂进行了表征。结果表明,催化剂的结构性质与研磨时间密切相关,催化剂的比表面积和铜原子的分散度随研磨时间延长先增大后减小,研磨2 h制得的催化剂显示了最高的催化活性。     

An efficient green procedure for the synthesis of chalcones using C-200 as solid support under grinding conditions

Abstract

A simple, rapid, efficient and environmentally benign procedure for the synthesis of chalcones has been achieved by grinding aryl aldehydes and acetophenones with anhydrous barium hydroxide (C-200) in the absence of any solvent. The use of organic solvent for extraction of compound is also avoided. This present method is highly useful for the synthesis of 2′-hydroxy chalcones, required intermediates for the synthesis of flavanoids.     

A simple fabrication method for tapered capillary tip and its applications in high‐speed CE and ESI‐MS

Fabrication of capillaries with tapered tips is an important technique that is required in many analytical chemistry areas, such as ESI‐MS, CE, electrochemical analysis, and microinjection. This paper describes a simple and effective grinding‐based fabrication method for capillaries with tapered tips. A novel grinding mode utilizing the combination of rotation and precession of an elastic capillary was developed, which significantly improved the controllability to the grinding process as well as the capillary tip shape. The capillary was fabricated by fixing it in an electric drill installed perpendicularly, and grind the capillary tip rotated around its own axis as well as the drill axis on sandpapers. Compared with conventional fabrication techniques for capillary tips, the present method is easy to control the capillary tip shape in routine laboratories without the requirement of expensive equipments or poisonous reagent (e.g. hydrofluoric acid (HF) solution). Various capillaries with different tip diameters and tip taper angles could be fabricated using the present method with good controllability and reproducibility. These capillaries were applied in high‐speed CE and ESI‐MS analysis to demonstrate the feasibility and potential of this fabrication method.