A confirmatory method for the simultaneous extraction,separation, identification and quantification of Tetracycline,Sulphonamide, Trimethoprim and Dapsone residues in muscle by ultra-high-performance liquid chromatography–tandem mass spectrometry according to Commission Decision 2002/657/EC

A rapid confirmatory multi-residue method for the analysis of tetracyclines, sulphonamides, trimethoprim and dapsone by UPLC-MS/MS is described. The method is able to quantify and confirm the following 19 compounds, oxytetracycline, tetracycline, chlortetracycline, doxycycline, sulfadiazine, sulfathiazole, sulfapyridine, trimethoprim, sulfamerazine, sulfamethizole, sulfamethazine, sulfamethoxypyridazine, sulfamonomethoxine, sulfachlorpyridazine, dapsone, sulfamethoxazole, sulfisoxazole, sulfaquinoxaline and sulfadimethoxine. Samples are extracted with 0.1 M EDTA and acetonitrile, which is then evaporated under a stream of nitrogen and reconstituted in water. Following centrifugation and filtering, an aliquot is analysed by UPLC-MS/MS using positive electrospray ionisation and multiple reaction monitoring. The method is deemed rapid as all analytes are extracted by a single extraction technique, with no solid-phase extraction clean up required. Validation is according to Commission Decision 2002/657/EC and was carried out for bovine, porcine, ovine and poultry species. Specificity, recovery, repeatability, reproducibility, CCα and CCβ data is presented.     

致癌性多环芳烃萘、蒽、芘的分析方法比较

利用薄层色谱（TLC）、紫外光谱（UV）、反相高效液相色谱（RPHPLC）对多环芳烃（PAHs）萘、蒽、芘的分析方法进行了研究。TLC中使用环己烷：氯仿（5：4,V／V）作为展开剂时,三者的R,值分别为0．78、0．65和0．72;用UV法在溶液中测定了三者的最大吸收波长分别为303、380、338nm;当流动相为甲醇：水（9：1,V／V）时三者在RP—HPLC中的保留时间为4．179、5．190、6．178min,5次重复RSD分别为1．1％、1．8％、0．91％,并用于实际水样中萘、蒽、芘的分析。     

MORPHOLOGY EVOLUTION IN PTFE AS A FUNCTION OF MELT TIME AND TEMPERATURE Ⅱ. LOW MOLECULAR WEIGHT FOLDED CHAIN SINGLE CRYSTALS AND BAND STRUCTURES

The effect of sintering dispersed and bulk, low molecular weight (Mn = 50,000 Da), nano-emulsion polytetrafluoroethylene (PTFE) particles near their melting point is described. With the nascent particles consisting of ca.75 nm diameter, hexagonal, single crystals, sintering at, e.g., 350℃, results, initially, in merger of neighboring particles,followed by individual molecular motion on the substrate and the formation of folded chain, lamellar single crystals and spherulites, and on-edge ribbons. It is suggested these structures develop, with time, in the mesomorphic "melt". Sintering of the bulk resin yields extended chain, band structures, as well as folded chain lamellae; end-surface to end-surface merger,possibly by end-to-end polymerization, occurs with increasing time.     

Simultaneous analysis of pesticides from different chemical classes by using a derivatisation step and gas chromatography-mass spectrometry

This work presents a new method to analyse simultaneously by GC–MS 31 pesticides from different chemical classes (2,4 D, 2,4 MCPA, alphacypermethrin, bifenthrin, bromoxynil, buprofezin, carbaryl, carbofuran, clopyralid, cyprodinil, deltamethrin dicamba, dichlobenil, dichlorprop, diflufenican, diuron, fenoxaprop, flazasulfuron, fluroxypyr, ioxynil, isoxaben, mecoprop-P, myclobutanil, oryzalin, oxadiazon, picloram, tau-fluvalinate tebuconazole, triclopyr, trifluralin and trinexapac-p-ethyl). This GC–MS method will be applied to the analysis of passive samplers (Tenax^® tubes and SPME fiber) used for the evaluation of the indoor and outdoor atmospheric contamination by non-agricultural pesticides. The method involves a derivatisation step for thermo-labile or polar pesticides. Different agents were tested and MtBSTFA (N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide), a sylilation agent producing very specific fragments [M−57], was retained. However, diuron could not be derivatised and the isocyanate product was used for identification and quantification. Pesticides which did not need a derivatisation step were not affected by the presence of the derivatisation agent and they could easily be analysed in mixture with derivatised pesticides. The method can be coupled to a thermal-desorption unit or to SPME extraction for a multiresidue analysis of various pesticides in atmospheric samples.     

Inorganic arsenic: A dangerous enigma for mankind

Human being have been using inorganic arsenic for a long time. Many reports on arsenic poisoning have been published: eg case reports, examination reports, post mortem reports, and epidemiological studies. Several aspects and features of arsenic poisoning are discussed in this report. Methods of inferring arsenic-related disease, disease classification according to acute or chronic criteria, exposure route, interaction, confounding factors, and the oxidation state of arsenic are all discussed. The effects of arsenic are classified into skin, respiratory system, gastrointestinal tract, liver, cardiovascular system, nervous system, and bone marrow effects. Carcinogenicity is an important chronic effect of arsenic poisoning, so special attention is paid to it in this review. In Japan, there have been many incidents of arsenic poisoning. In this review, we often use data from these cases, such as the Morinaga powdered-milk poisoning case, the Ube soy-sauce poisoning case, the Toroku mine incident, and the Nakajo well-water poisoning case. We emphasize here the necessity of planning follow-up studies and total health care for patients exposed to arsenic.     

Three types of reactions with intramolecular five-membered ring compounds in organic synthesis

There are three types of reactions with intramolecular five-membered ring compounds in organic syntheses: The first type is reactions involving intramolecular five-membered ring compounds which are utilized for the ease of synthesis of these compounds and the stability of the products. The second is reactions performed via intramolecular five-membered ring intermediates, because such intermediates are very reactive and labile compounds. The third is the metal-catalyzed reactions with the intramolecular five-membered ring compounds because these metal compounds have catalytic activities. The third type reactions involving intramolecular five-membered ring pincer compounds are also provided.The first type reactions include carbonylations, alkenylations, alkynylations, acylations, isocyanations, Diels-Alder reactions, etc. The second type reactions include carbonylations, cross-coupling reactions, hydroacylations, ring expansion reactions, carbocyclizations, etc. The third type reactions include cross-coupling reactions, rearrangements, metatheses, reductions, Michael reactions, dehydrogenations, Diels-Alder reactions, etc.     

铋系超导体组成分析

本文首次提出了一种离子交换柱分离——滴定法测定Bi系超导体中Bi、Pb、Cu、Ca和Sr含量的方法。研究了进样条件和淋洗方法,特别是Bi~(3+)在微酸性溶液中的亚稳态进样。测定合成样品时,Bi、Pb、Cu、Ca和Sr的相对标准偏差分别为0.7％、1.6％、0.5％、0.4％和0.2％。分析了超导体样品,并测定了其中Cu~(3+)。     

Determination of the Pesticides Alachlor,Anilazine, Bromoxynil,and Dichlobenil by Low Temperature Phosphorimetry

Abstract

Sensitive low temperature phosphorimetric methods for the determination of the pesticides Alachlor, Anilazine, Bromoxynil, and Dichlobenil in EPA solvent have been developed. The minimum detectable amounts are 0.08, 0.006, 0.2, and 0.006 p.p.m. for Alachlor, Anilazine, Bromoxynil, and Dichlobenil respectively. The ranges in linearity of the analytical calibration graphs are 0.01–5, 0.2–7.5, and 0.03–20 p.p.m. for Anilazine, Bromoxynil, and Dichlobenil respectively. The analytical calibration graph for Alachlor is linear from 0.3 to 10 p.p.m. and with a different slope, linear from 10 to 50 p.p.m. The procedure for Alachlor has been applied to the analys of a solid commercial formulation.     

Multi-Elemental Analysis as a Tool to Ascertain the Safety and the Origin of Beehive Products: Development,Validation, and Application of an ICP-MS Method on Four Unifloral Honeys Produced in Sardinia,Italy

Despite unifloral honeys from Sardinia, Italy, being appreciated worldwide for their peculiar organoleptic features, their elemental signature has only partly been investigated. Hence, the principal aim of this study was to measure the concentration of trace and toxic elements (i.e., Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sb, Sn, Sr, Te, Tl, V, and Zn) in four unifloral honeys produced in Sardinia. For this purpose, an original ICP-MS method was developed, fully validated, and applied on unifloral honeys from asphodel, eucalyptus, strawberry tree, and thistle. Particular attention was paid to the method’s development: factorial design was applied for the optimization of the acid microwave digestion, whereas the instrumental parameters were tuned to minimize the polyatomic interferences. Most of the analytes’ concentration ranged between the relevant LoDs and few mg kg⁻¹, while toxic elements were present in negligible amounts. The elemental signatures of asphodel and thistle honeys were measured for the first time, whereas those of eucalyptus and strawberry tree honeys suggested a geographical differentiation if compared with the literature. Chemometric analysis allowed for the botanical discrimination of honeys through their elemental signature, whereas linear discriminant analysis provided an accuracy level of 87.1%.     

Traditional uses,phytochemistry, pharmacology and other potential applications of Vitellaria paradoxa Gaertn. (Sapotaceae): A review

Vitellaria paradoxa Gaertn. is a multipurpose medicinal plant of the family Sapotaceae, and it has been widely used usually in the clinical traditional medicine as remedy for a wide range of diseases for several decades. In addition, the plant has also found applications in confectionery, cosmetics and soaps, and pharmaceuticals both locally and internationally. V. paradoxa, which has been identified with >150 phytoconstituents, is rich in oleanane-type triterpene acids and glycosides, such as paradoxosides A-E, tieghemelin A, parkiosides A-C, bassic acid, as well as flavonoids such as quercetin and catechin-type compounds. The extracts and the active constituents of V. paradoxa have been investigated for various pharmacological activities, including but not limited to anticancer, melanogenesis-inhibitory, antibacterial, anti-diabetic, antioxidant, anti-inflammatory, anti-diarrhoeal, and antifungal activities. Additionally, V. paradoxa has also been utilized in nanoparticles (NPs) synthesis. These NPs among other things have shown significant antinociceptive and antiedematogenic activities as well as environmental friendly adsorptive properties for the removal of pollutants from pharmaceutical effluents. Overall, this review comprehensively examines the traditional uses, phytochemistry, pharmacology, toxicology, clinical studies, and nanoparticles synthesized from V. paradoxa and their applications.     

Self-Assembling Drug Formulations with Tunable Permeability and Biodegradability

This review focuses on key topics in the field of drug delivery related to the design of nanocarriers answering the biomedicine criteria, including biocompatibility, biodegradability, low toxicity, and the ability to overcome biological barriers. For these reasons, much attention is paid to the amphiphile-based carriers composed of natural building blocks, lipids, and their structural analogues and synthetic surfactants that are capable of self-assembly with the formation of a variety of supramolecular aggregates. The latter are dynamic structures that can be used as nanocontainers for hydrophobic drugs to increase their solubility and bioavailability. In this section, biodegradable cationic surfactants bearing cleavable fragments are discussed, with ester- and carbamate-containing analogs, as well as amino acid derivatives received special attention. Drug delivery through the biological barriers is a challenging task, which is highlighted by the example of transdermal method of drug administration. In this paper, nonionic surfactants are primarily discussed, including their application for the fabrication of nanocarriers, their surfactant-skin interactions, the mechanisms of modulating their permeability, and the factors controlling drug encapsulation, release, and targeted delivery. Different types of nanocarriers are covered, including niosomes, transfersomes, invasomes and chitosomes, with their morphological specificity, beneficial characteristics and limitations discussed.     

Physico-chemical properties of Chitosan films

Chitosan films obtained by dry phase inversion were prepared from an aqueous solution of chitosan in acetic acid. The films, of thickness less than 20 μm, were transparent, very flexible and had smooth surfaces. Increasing the film thickness induced an increase of the internal tensions and the consequent formation of a rough surface. Structural investigations by X-ray diffraction and Fourier transform IR analysis, showed that the chitosan films, as prepared, are amorphous. Further annealing to evaporate acetic acid and water traces, changed the amorphous phase into a more ordered phase, characterized by diffraction peaks at 2θ values of 9, 17, 20 and 23 degrees. Thermal investigations by TG, DTG, and DTA revealed that the decomposition of the chitosan films as prepared proceeds in two stages, starting from 180°C and 540°C.     

From halo-azasilylenes to halo-phosphasilylenes (X-CNSi vs. X-CPSi) at ab initio and DFT levels

The higher the electropositivity of the substituents has been associated with the higher possibility of encountering a triplet ground state silylene [P.P. Gaspar, M. Xiao, D. Ho Pae, D.J. Berger, T. Haile, T. Chen, D. Lei, W.R. Winchester, P. Jiang, J. Organomet. Chem. 646 (2002) 68]. Here, going from the reported halo-azasilylenes X-CNSi [M.Z. Kassaee, S.M. Musavi, H. Hamadi, M. Ghambarian, S.E. Hosseini, J. Mol. Struct. (Theochem) 730 (2005) 33] to the analogues more electropositively substituted halo-phosphasilylenes X-CPSi has reduced the chances of encountering triplet ground state silylenes (X = H, F, Cl and Br). Even though all singlet isomers seem to be more stable than their corresponding triplets, singlet-triplet cross over diagrams may help the future design of new acyclic triplet state silylenes.     

Advances in Research on Food Bioactive Molecules and Health

Fresh and processed food products are rich in bioactive molecules, including polysaccharides, vitamins, carotenoids, peptides, antioxidants, phenolics, phytosterols, and novel lipids. Bioactive molecules in food could prevent several diseases (i.e., metabolic syndrome, cardiovascular diseases, cancer, etc.). Thus, consumer awareness is growing about the health-promoting impact of food bioactive molecules. Health claims are essential added-value features, wherein health-enhancing potential of bioactives depend on their chemical structure. On the other hand, the investigation of the structure-function relationship of food bioactive molecules is of importance. In this regard, Molecules is delighted to highlight the importance of food bioactive molecules and their effect on health. In this Special Issue of Molecules, researchers are invited to contribute original research and up-to-date reviews.     

Simultaneous Determination of Cadmium,Mercury, Lead,Arsenic, Copper,and Zinc in Human Breast Milk by ICP‐MS/Microwave Digestion

Abstract

An analytical method using microwave digestion and inductively coupled argon plasma-mass spectrometry (ICP‐MS) analysis was developed for the measurement of Cd, Hg, Pb, As, Cu, and Zn in human breast milk. We applied external calibration, internal calibration, and standard addition for reference material and pooled milk analysis. Method performances were defined in terms of detection limits, accuracy, and precision. Accuracy varied between 93% and 105% and precision between 3% and 8%. External calibration and background interferences were checked through a calibrator addition procedure. Our method has shown high accuracy, precision, and sensitivity, as well as linearity within a wide range of values. Our methodology, developed by treatment of reference material and pooled milk samples, was applied for determination of Cu, Zn, As, Cd, Hg, and Pb in 120 human breast milk samples.     

金属气凝胶：可控制备与应用展望

作为多孔材料家族的最新成员之一,金属气凝胶(Metal aerogels,MAs)是完全由纳米结构金属构筑而成的一类新型气凝胶。MAs兼有金属独特的物理化学性质与气凝胶的结构特征,同时拥有高速传质通道、高导电性三维网络、自支撑性与独特的光学特性,故在电催化、表面增强拉曼散射和生物传感等领域均表现出卓越性能。然而,MAs的研究历史较短,其可控制备、构效关系探索等研究存在众多挑战性问题,距离商业化应用尚有较长的道路。因此,系统梳理MAs的研究工作,从中汲取经验与总结设计原理是极为有益的。本文将对MAs的合成策略、应用研究进行系统评述,在此基础上对本领域的挑战与机遇进行总结展望。希望招徕更多科研工作者,共同探索MAs这一年轻而前景广阔的新材料领域。     

Perkin-Elmer introduce new gas chromatograph

Abstract

APPLICATIONS OF MASS SPECTROMETRY TO TRACE ANALYSIS. Ed. S. Facchetti, Elsevier, US $78.75, Dfl. 185.00.

QUANTITATIVE AQUATIC BIOLOGICAL INDICATORS. by David J. H. Phillips, Fisheries Research Station Aberdeen, Hong Kong, POLLUTION MONITORING SERIES (1980), 488 pages (including 99 figures, 103 tables, 44 pages of literature references up to 1978, an author index of 10 pages, a species index of 4 pages, and a subject index of 18 pages), linen, format 228 × 148 mm, ISBN 0-85334-884-7, Applied Science Publishers Ltd., London, £26.

DIRECTORY OF POLLUTION CONTROL EQUIPMENT COMPANIES IN WESTERN EUROPE, Third Edition (1980), 588 pages (including an index of 127 pages, which is however-structured somewhat arbitrarily according to types of equipment and according to countries), stiff paper cover, format 210 × 147 mm, ISBN 0 906685 00 1, European Directories, a Division of Inter Company Comparisons Ltd., 23, City Road, London EC1Y 1AA, £30.

HALOGENATED BIPHENYLS, TERPHENYLS, NAPHTHALENES, DIBENZODIOXINS AND RELATED PRODUCTS, by R. D. Kimbrough (ed.) (Elsevier Biomedical Press, R.V., Amsterdam, NL. U.S. $95.00, Dfl 195.

CHROMATOGRAPHY AND THE ENVIRONMENT, Environmental problem solving using gas and liquid chromatography, R. L. Grob and M. A. Kaiser, Elsevier, Amsterdam, 1982, XII + 240 pages, ISBN 0-444-42065-7     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Chemical Reactions of 2-Methyl-5,7-diphenyl-6,7-dihydropyrazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidine

The hydrolysis, oxidation, reduction, alkylation, formylation, and nitrosation reactions of 2-methyl-5,7-diphenyl-6,7-dihydropyrazolo[1,5-a]pyrimidine have been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 577–581, April, 2005.     

Recent trends on electrochemical carbon-based nanosensors for sensitive assay of pesticides

Pesticides are substances or mixtures used to prevent, control, and reduce harmful organisms, are divided into various groups as carbamates, organophosphates, organochlorines, pyrethroids, fungicides, herbicides, and rodenticides. Uncontrolled and long-term use of pesticides has become an important issue that causes environmental pollution and health problems. Therefore, it is necessary to develop effective sensors to determine pesticides in various samples. Electrochemical techniques stand out with high sensitivity, easy application, low cost, and user-friendliness, among other analysis techniques such as spectroscopic and chromatographic methods. Furthermore, carbon nanomaterials are advantageous materials for the sensor design as modification agents due to their unique electrical, physical, electrocatalytic, and chemical features. In this review, the most significant studies on the electroanalysis of pesticides (e.g., carbaryl, carbofuran, chlorpyrifos, malathion, methyl parathion, paraoxon) using carbon-based nanosensors in the last five years are overviewed. In addition, electrochemical methods and the carbon nanomaterials used in these studies are also evaluated.