新一代萃取分离技术──固相微萃取

介绍了一种新型样品制备法——固相做萃取（SPME）的原理及其应用。与其它样品制备技术相比,SPME法具有操作时间短、样品量小、无需萃取溶剂、适于分析挥发性与非挥发性物质、重视性好等优点。     

固相萃取技术在食品痕量残留和污染分析中的应用

食品痕量残留和污染分析中,样品的前处理极为重要,也是其难点所在。由于食品和农产品样品的多样性和复杂性,目前还没有一种前处理技术能够适合所有情况下的所有样品。本文对近年来发展起来的新型固相萃取技术如固相微萃取、搅拌棒吸附萃取、基质固相分散萃取、分子印迹固相萃取、免疫亲和固相萃取、整体柱固相萃取、碳纳米管固相萃取等在食品痕量残留和污染分析中的应用进行了综述,对未来的发展前景作了展望。     

环境样品中双酚类化合物的固相萃取研究进展

双酚类化合物作为一类内分泌干扰物广泛存在于环境介质中,经过多种途径迁移至人体后,可对人体产生内分泌毒性、细胞毒性、基因毒性、生殖毒性、二噁英毒性和神经毒性,已被加拿大政府风险评估识别为进一步优先控制名录。随着环境领域对双酚类化合物的广泛关注,相关研究工作逐渐向水、沉积物、灰尘和生物样品等多介质开拓。但是,由于不同环境样品在基质复杂性和污染物浓度水平等方面存在显著差异,开发提取效率高、净化选择性好、普适性强、操作简单、高通量的提取和净化方法,有助于实现环境介质中双酚类化合物的高灵敏、批量检测。近年来,新型前处理技术发展迅速,尤其是固相萃取技术,在双酚类化合物提取与净化方面取得了长足的发展,不仅在一定程度上克服了传统提取净化方法存在的耗时、耗力和耗溶剂等不足,而且为新型污染物分析提供了更多的技术支持。该文简述了典型双酚类化合物的理化性质、用途用量和环境危害,重点围绕新型固相萃取吸附剂开发和固相萃取模式转变两个方面,总结了固相萃取在双酚类化合物提取净化方法方面取得的进展。商品化固相萃取产品普适性强,在环境监测领域应用范围较广,适用于双酚类化合物的产品种类有限;新型吸附剂研发聚焦吸附容量(如介孔硅材料、碳纳米材料、金属-有机框架材料、环糊精)和选择性(如分子印迹聚合物和混合模式离子交换聚合物)两个方面,种类多样化可满足不同检测需求;越来越多的高灵敏分析仪器不断推向市场,为适应新的发展形势,固相萃取模式正逐渐向微型化、自动化、简易化等方向发展,如QuEChERS、固相微萃取、磁固相萃取等。     

石墨相氮化碳材料在样品前处理中的研究进展

作为一种新型非金属材料,石墨相氮化碳以其独特的优点,如简单的制备方法、优良的化学及热稳定性、良好的生物兼容性和无毒性等,受到越来越多的关注。石墨相氮化碳及其复合材料目前已被广泛应用于电催化、光催化、生物成像等领域。由于具有大的比表面积,同时又是富电子的疏水材料,石墨相氮化碳相关材料被认为是一种理想的样品前处理吸附剂。该文探讨了近年来石墨相氮化碳及其复合材料作为固相萃取、分散固相萃取、磁性固相萃取、固相微萃取吸附剂在样品前处理中的应用,并对未来的发展趋势和应用前景进行了展望,以期为相关领域的研究提供帮助。     

固相微萃取与色谱联用方法分析水中12种有机氯化合物

运用顶空固相微萃取与色谱闻用方法（ＨＳ－ＳＰＭＥ－ＧＣ）对水中的残留有机氯化合物进行了分析。对影响ＨＳ－ＳＰＭＥ－ＧＣ分析灵敏度的各种实验因素如涂层种类,萃取温度、平衡时间,离子浓度等进行了讨论并将该方法与固相萃取法（ＳＰＥ）,液液萃取法（ＬＬＥ）作了对比,同时考察了常见环境共存污染物直链烷基苯磺酸钠（ＬＡＳ）对几种方法的影响。     

金属有机骨架复合材料在样品预处理中的研究进展

金属有机骨架（MOFs）材料是近几年涌现出的一类新型多功能多孔材料,以金属离子或金属簇为配位中心,与含氧或氮的有机配体通过配位作用形成多孔骨架结构。相比于其他传统无机多孔材料,MOFs具有比表面积高、孔隙率大、热稳定性好和结构与功能多样化的特点,因而被广泛用于气体存储、催化、吸附和分离等领域。MOFs复合材料在样品预处理方面的应用引起了研究者们的极大兴趣和广泛关注。由于MOFs材料和不同功能材料如高分子聚合物、碳基材料以及磁性材料组装复合,使MOFs复合材料的性能优于原来的MOFs材料。综述了近年MOFs复合材料在样品预处理的研究应用,尤其是在固相微萃取、固相萃取以及磁性固相萃取等方面的应用。     

金属有机骨架应用于样品前处理研究的最新进展

作为一类新型多孔晶体材料,金属有机骨架（MOFs）在储能、催化、传感和分离等领域得到了广泛应用。MOFs多样的拓扑结构、大的比表面积和可调的孔径使得其在样品前处理领域拥有广阔的应用前景,基于MOFs及其衍生材料的样品预处理新方法层出不穷。该文总结了近几年MOFs粉末、MOFs膜、MOFs纳米片和MOFs复合材料等应用于固相萃取、固相微萃取和磁固相萃取等样品前处理技术的研究进展,并对该领域研究进行了展望。     

糖肽的固相合成

目前糖肽的固相合成可以分为两种策略：构建单元策略和固相糖基化策略。本文对O-连接和N-连接糖肽固相合成的研究进展进行了综述。     

氮化碳及其复合材料在样品前处理领域的应用

氮化碳(g-C_3N_4)是一种新型二维碳纳米材料,目前已在催化降解、生物传感、能源存储和生物医药等领域得到了广泛应用。g-C_3N_4材料结构中丰富的含氮官能团和电子离域特性,赋予其独特的理化性质,使之能够与一些离子或分子产生络合、疏水、π-π键、氢键和静电力等相互作用。此外,g-C_3N_4材料比表面积大、性质稳定且制备简单,价格低廉,在样品前处理领域展现出良好的应用潜力。近几年,基于g-C_3N_4材料的样品前处理新方法不断涌现,该文总结了g-C_3N_4及其复合材料在固相萃取、磁性固相萃取和固相微萃取等领域的应用并进行了展望。     

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.     

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.     

电感耦合等离子发射光谱法测定镍铁中Si,Mn,P,Ni

建立ICP–AES法测定新型材料镍铁中的Si,Mn,P,Ni元素的方法。考察了镍铁基体和共存元素对测定结果的影响。通过基体匹配消除基体干扰,确定各待测元素谱线为Mn 293.930 nm,P 178.280 nm,Ni 231.604 nm,Si251.611 nm。Si,Mn,P,Ni的检出限分别为0.06,0.04,0.08,0.04 mg/L,测定结果的相对标准偏差均小于5%(n=11),加标回收率在95%~105%之间。该方法操作简便、测定结果准确可靠,可用于镍铁中Si,Mn,P,Ni的含量测定。     

微波消解-微波等离子体矩原子发射光谱法测定乳胶管中的铁、钙、镍、镁、锌

本文研究了用HNO3-H2O2微波消解样品,微波等离子体矩原子发射光谱(MPT-AES)测定乳胶管中铁,钙,镍,镁,锌的含量方法。详细考察了测定铁、钙、镍、镁、锌的最佳实验条件,以及介质酸、共存离子的影响。本方法测定铁、镍、镁、钙、锌的检出限分别为77.80、7.55、2.70、275.87、46.23 ng/mL,方法的精密度分别为3.10%、2.19%、2.22%、1.27%、2.90%,线性范围分别为0.08~2 mg/L0、.06~2 mg/L0、.001~3 mg/L、0.005~2 mg/L、0.05~1 mg/L,加标回收率分别在97.7%~107.8%、96.0%~106.7%、98.0%~106.2%、92.3%~108.8%、98.7%~106.8%范围。     

电感耦合等离子体原子发射光谱法测定纯银中镉、铋、铁、铅、锑、钯、硒、碲

样品用硝酸溶解,加入过量盐酸沉淀分离银,过滤后利用电感耦合等离子体原子发射光谱法测定镉、铋、铁、铅、锑、钯、硒、碲,方法检出限分别为:0.0028,0.0075,0.0036,0.011,0.010,0.021,0.0075,0.0039μg/mL;加标回收率为98.1%～114.3%;RSD小于4.2%,方法能同时准确测定镉、铋、铁、铅、锑、钯、硒、碲,满足日常分析要求。     

Nondestructive characterization of nanoscale layered samples

Multilayered samples consisting of Al, Co and Ni nanolayers were produced by MBE and characterized nondestructively by means of SRXRF, μ-XRF, WDXRF, RBS, XRR, and destructively with SIMS. The main aims were to identify the elements, to determine their purity and their sequence, and also to examine the roughness, density, homogeneity and thickness of each layer. Most of these important properties could be determined by XRF methods, e.g., on commercial devices. For the thickness, it was found that all of the results obtained via XRR, RBS, SIMS and various XRF methods (SRXRF, μ-XRF, WDXRF) agreed with each other within the limits of uncertainty, and a constant deviation from the presets used in the MBE production method was observed. Some serious preliminary discrepancies in the results from the XRF methods were examined, but all deviations could be explained by introducing various corrections into the evaluation methods and/or redetermining some fundamental parameters.     

野生和种植翅果油树果实中微量元素的分析比较

采用火焰原子吸收光谱法对野生和种植翅果油树不同形状果实的果仁、果皮、果壳中Cu、Zn、Fe、Mg、Ca、K、Na、Mn 8种微量元素进行了分析比较.结果显示:在果仁果皮果壳中,8种微量元素的含量是K＞Mg＞Ca＞Fe＞Na＞Zn＞Mn＞Cu,其中果仁的Cu、Zn、Mg含量高.在果仁中Zn、Mg、K、Na、Mn是野生＞种...     

A Facile and Efficient Synthesis of 2‐(5‐(4‐Substitutedphenyl)‐4, 5‐dihydro‐3‐phenylpyrazol‐1‐yl)‐6‐Substitutedbenzothiazoles and Their Biological Studies

A series of new 1‐substituted 3, 5‐diarylpyrazolines ( 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ) were synthesized in good yield by both conventional and microwave‐assisted synthesis from α, β‐ unsaturated ketones ( 6 , 7 , 8 , 9 ) in n‐butanol and benzothiazole hydrazines ( 2 , 3 , 4 , 5 ). All the new compounds were characterized by IR, NMR, and mass spectral data. The synthesized compounds ( 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ) were evaluated for antibacterial and anthelmintic activities. The compounds showed potent anthelmintic activity against earthworm species (Eudrilus eugeniae) and moderate antibacterial activity against bacterial strains such as Gram positive bacteria, Enterococcus faecalis, Staphylococcus aureus, and Bacillus subtilis, and Gram negative bacteria, Escherichia coli and Proteus mirabilis.     

Silyl group deprotection by Pd/C/H2. A facile and selective method

An easy, high yield, RT, short-reaction-time Pd/C hydrogenation of silyl groups is described. This includes TES, TPS, TBS, TBDMS, TIPS, and TBDPS. The relative selectivity of the process has been investigated and we can show, for example, that TES, TPS, TBS, and TBDMS removal can be performed in the presence of TIPS and TBDPS.     

The ethnobotanical,phytochemistry and pharmacological activities of Psidium guajava L.

Psidium guajava L., commonly known as guava is an important tropical food plant with diverse medicinal values. In traditional medicine, it is used in the treatment of various diseases such as diarrhoea, diabetes, rheumatism, ulcers, malaria, cough, and bacterial infections. The aim of this review is to provide up-to-date information on the ethnomedicinal uses, bioactive compounds, and pharmacological activities of P. guajava with greater emphasis on its therapeutic potentials. The bioactive constituents extracted from P. guajava include phytochemicals (gallic acid, casuariin, catechin, chlorogenic acid, rutin, vanillic acid, quercetin, syringic acid, kaempferol, apigenin, cinnamic acid, luteolin, quercetin-3-O-α-L-arabinopyranoside, morin, ellagic acid, guaijaverin, pedunculoside, asiastic acid, ursolic acid, oleanolic acid, methyl gallate and epicatechin) and essential oils (limonene, trans-caryophyllene, α-humulene, γ-muurolene, selinene, caryophyllene oxide, bisabolol, isocaryophyllene, δ-cadinene, α-copaene, α-cedrene, β-eudesmol, α-pinene, β-pinene, β-myrcene, linalool, α-terpineol and eucalyptol). In vitro and in vivo studies demonstrated that P. guajava possesses pharmacological activities such as antidiabetic, antidiarrhoeal, hepatoprotective, anticancer, antioxidant, anti-inflammatory, antiestrogenic, and antibacterial activities which support its traditional uses. The exhibited pharmacological activities reported may be attributed to the numerous bioactive compounds present in different parts of P. guajava. Based on the beneficial effects of P. guajava as well as its bioactive constituents, it can be exploited in the development of pharmaceutical products and functional foods. However, there is a need for comprehensive studies in clinical trials to establish the safe doses and efficacy of P. guajava for the treatment of several diseases.