凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

加速溶剂萃取-固相萃取净化-气相色谱/质谱法测定沉积物中多氯联苯和多环芳烃

建立了加速溶剂萃取-固相萃取净化-气相色谱/三重四极杆串联质谱联用(ASE-SPE-GC-QqQ-MS/MS)法同时测定沉积物中28种多氯联苯(PCBs)和16种多环芳烃(PAHs)。对萃取、净化及仪器分析条件进行了优化。优化条件为:ASE萃取温度90℃,萃取时间6 min;净化小柱为硅胶-Florisil固相复合柱(填料自下而上为弗罗里硅土、0.7 g活化硅胶、1 g无水硫酸钠);洗脱溶液为丙酮-正己烷(1∶19,V/V)混合溶液,洗脱速率为0.6 mL/min。PCBs和PAHs在2～500μg/L和5～1000μg/L浓度范围内的线性相关系数(R2)分别为0.9987～0.9999和0.9939～0.9999;PCBs和PAHs方法检出限分别为0.001～0.08 ng/g和0.07～0.45 ng/g;定量限为0.003～0.25 ng/g和0.24～1.67 ng/g;实际样品平均加标回收率为95.6%～125.7%和70.4%～124.7%;方法相对标准偏差(n=6)为0.7%～6.4%和1.1%～12.8%。运用本方法对滇池入湖河口表层沉积物样品进行测定,该区域PCBs单体浓度为n.d.(未检出)～0.13 ng/g,PAHs单体浓度为0.79～131.12 ng/g。     

气相色谱-串联质谱法测定得克隆及其相关化台物在土壤样品中的含量

建立了得克隆(DP)及其脱氯产物和结构类似物等共11种化合物的气相色谱-串联质谱联用分析方法,并用于环境土壤中目标物的分析和污染特征研究.土壤样品抽提液经多段硅胶-氧化铝柱净化后,采用如下仪器条件分析:电子轰击电离源;选择反应离子对监测模式;DB-5HT毛细管柱(15 m×0.25 mm i.d.,0.1μm);进样口温度260℃,传输线温度280℃,离子源温度250℃;无分流进样1μL,载气为氦气(1.5 mL/min).实验结果表明,测定DP及其相关化合物的标准曲线线性范围为4~5个数量级,线性相关系数在0.9977~0.9999之间,仪器检出限在0.005~0.100 pg之间,方法检出限为0.25~5.00 fg/g,50 pg/μL标准样品平行5次进样的相对标准偏差(RSD)为1.1%~19.8%.对某典型污染区及其周边地区土壤进行分析,其中DP及相关化合物的总浓度在0.275~681 ng/g dw之间,检出率100%;单个目标物浓度在n.d.~537 ng/g dw之间,其中anti-DP和syn-DP为优势污染物,样品及质控样品中两种回收率指示物的加标回收率分别为55.0%~103.0%和83.4%~107.0%,空白/基质加标样品中目标物的平均回收率和RSD分别为53.9%~117.0%和6.0%~19.1%.     

GC-NCI/MS法分析海水中得克隆类物质

建立了固相萃取-气相色谱-负化学源质谱联用法(SPE-GC-NCI/MS)同时测定海水中5种得克隆类物质的方法。采用二氯甲烷进行液液萃取(LLE),萃取液经过硅胶固相萃取小柱净化后,在15 m长的DB-5HT高温毛细管气相色谱柱上分离,NCI/MS以选择离子监测模式检测目标化合物。方法中5种得克隆类物质Dec 602,Dec 603,Syn DP和Anti DP的检出限分别为0.01,0.01,0.08,0.02和0.01 ng/L,平均加标回收率分别为61%,75%,75%,87%和91%,RSD均小于5.1%。采用该法对河北近岸海域16个采样站位海水样品进行分析,所有采样站位均有得克隆类物质检出。     

粗径毛细管气相色谱法测定F8426在土壤和小麦中的残留量

 用气相色谱法测定了快灭灵 40 %干悬浮剂中F842 6在土壤和小麦中的残留量。用丙酮 水 (体积比为 80∶2 0 )溶液提取土壤和小麦样本中的F842 6 ,然后用石油醚萃取。石油醚相经浓缩后过弗罗里硅土和活性炭 (0 97g +0 0 3g)混合小柱净化 ,再用OV 170 1粗径毛细管柱分离 ,用电子捕获检测器 (ECD)测定。该方法对F842 6的最小检出量为 0 0 2ng ,在小麦和土壤中F842 6的最低检出限分别为 2 μg/kg和 1μg/kg ,对土壤和小麦空白样本的平均添加回收率为 89 6 0 %～ 97 5 3%,变异系数为 4 42 %～ 8 6 7%。。     

凝胶渗透色谱净化-气相色谱-质谱法同时测定金银花中33种农药残留组分

建立了凝胶渗透色谱(GPC)净化、气相色谱-质谱(GC-MS)同时测定金银花中33种有机氯、有机磷和拟除虫菊酯农药残留的方法.样品中的待测农药组分经乙酸乙酯-环己烷混合溶剂(1∶ 1, V/V)提取、GPC净化去除色素等杂质,GC-MS采用全扫描/选择离子监测模式(Scan/SIM)采集数据后进行定性/定量分析.方法的相对标准偏差(RSD)≤16.70 %(6.9～84.6 ng/g,n=5);5种不同加标浓度下,待测农药的标准加入回收率在57.4%(甲胺磷)～109.9%(马拉硫磷)之间;各农药组分的定性检出限(3σ)为0.10～10.5 ng/g,定量检出限(10 σ)为0.33～20.0 ng/g.     

固相萃取/气相色谱-串联质谱法测定竹笋产地土壤中42种持久性有机污染物

建立了同时测定竹笋产地土壤中8种多环芳烃(PAHs)、18种多氯联苯(PCBs)和16种有机氯农药(OCPs)的方法。样品经丙酮-正己烷(1∶1,体积比)大功率超声提取,复合弗罗里硅土柱固相萃取净化、氮吹浓缩后,利用气相色谱-三重四极杆质谱(GC-MS/MS)测定。结果表明,42种持久性有机污染物(POPs)在35 min内得到分离,在2. 0～2 000. 0μg/L范围内线性关系良好,相关系数(r2)为0. 995 2～0. 999 8;方法的加标回收率为62. 3%～128%,相对标准偏差(RSD)为0. 5%～15. 8%,检出限(S/N=3)为0. 070～6. 902μg/kg。该法操作简便,准确度好,灵敏度高,可用于竹笋产地土壤样品中42种POPs的同时测定。     

基质固相分散-加速溶剂萃取-气相色谱法测土壤中有机氯农药残留

建立了用弗罗里硅土作基质固相分散剂的加速溶剂萃取、并以灭蚁灵（Mirex）为内标的快速、同时测定土壤中16种有机氯农药的气相色谱法。加速溶剂萃取仪在100℃,10．3Mpa用正己烷和丙酮（1：1,V／V）静态提取样品10min,0．01μg/g加标水平回收率为77．3％-101．3％;方法检出限为0．01—0．04ng／g。方法满足了土壤中有机氯农药残留测定的要求。对我国南方不同地域的72个土壤样品进行了测定,大部分有机氯农药在土壤中都有一定检出量,其中环氧七氯最高（2．6～844．5ng／g）,甲氧DDT（23．2—219．8ng／g）和P,P’-DDT（4．0—183．1ng／g）次之,而o,P＇-DDT在72个土样中都没有检出。     

工作场所空气中54种挥发性烃类物质的检测

采用Tenax-TA吸附剂管采集工作场所空气中54种挥发性烃类化合物,经热脱附-气相色谱检测。结果显示,1,1-二氯乙烯、二氯甲烷、1,2-二氯乙烯(反式)、1,2-二氯乙烯(顺式)、2,2-二氯丙烷、溴氯甲烷、1,1,1-三氯乙烷、1,2-二氯乙烷、1,1-二氯丙烯的相关系数在0.9941～0.9986之间,溴氯甲烷、二溴甲烷、三氯甲烷、溴二氯甲烷、2,2-二氯丙烷、二溴氯甲烷、溴仿的检出限为5.4～10.3ng,最低检出浓度0.01～0.1mg/m3(采样体积0.5L)。其余38种挥发性烃类物质的相关系数均大于0.999,最低检出浓度0.001～0.01mg/m3;其中烯烃类检出限为0.4～2.7ng、烷烃类为1.4～3.7ng、芳香烃类为0.2～1.0ng、萘为2.2ng;54种挥发性烃类物质的热脱附效率92.1%～113.1%,RSD为0.6%～17.4%,除1,2-二氯乙烯(顺式)、1,1-二氯乙烷、1,1,1-三氯乙烷、1,1-二氯乙烯、2,2-二氯丙烷、三氯甲烷、1,2-二氯乙烯(反式)、二氯甲烷、溴氯甲烷的RSD值在5.1%～17.4%外,其余45种挥发性烃类物质的RSD均小于5%;9种化合物...     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

Synthesis of Some Novel Class of Bis(isoxazoline) and Bis(aziridine) Derivatives

Synthesis of some new bis(isoxazoline) derivatives has been described from terepthaldehyde derived bis(nitrones) using microwave irradiation via 1,3‐dipolar cycloaddition reaction. Bis(isoxazoline) derivatives in turn successfully converted into new bis(aziridine) derivatives via Baldwin rearrangement. Simple reaction methodology, non involvement of catalysts, and good to excellent yields are the important features noticed in this synthesis.     

柴油加氢精制催化剂制备技术

柴油加氢精制催化剂制备技术的发展大致经历了3个阶段,由此形成了三代柴油加氢催化剂:单层分散的负载型金属硫化物催化剂,多层分散的负载型金属硫化物催化剂和非负载型金属硫化物催化剂。本文对金属硫化钼基柴油加氢精制催化剂的应用背景、制备思想及催化剂研究开发现状进行了系统的总结,对柴油加氢催化剂的发展方向进行了展望。     

Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals

Coordination compounds based on imidazole and benzimidazole substituted nitronyl nitroxide radicals with transition metal ions and trivalent lanthanide ions are described from the perspective of their magnetic properties.For the transition metal compounds the crystal structures show various metal-nitroxide dimensionalities including mononuclear (0D), one-dimensional (1D) and two-dimensional (2D) complexes. The mononuclear complexes were isolated with most metal ions of the first transition series. One copper(II) complex shows a copper(II)-radical ferromagnetic coupling (J = +75 cm⁻¹) while for the other mononuclear compounds, mainly with manganese(II), the metal-radical interactions are antiferromagnetic. The one-dimensional and two-dimensional complexes are manganese(II) compounds which show canting effects leading to weak ferromagnetism.For the trivalent lanthanide ions [La(III), Gd(III) and Eu(III)], three series of mononuclear complexes were obtained in which the metal center is bound to four, two or one nitroxide radicals depending on the counter ions and ancillary ligands. Unexpectedly, in most gadolinium(III) complexes, the Gd(III)-radical interactions were found to be antiferromagnetic in contradiction with other foundings and previous theoretical models. In support to the magnetic studies, the optical properties of the lantanide complexes have also been investigated and are briefly described.     

Transition metal complexes of the tripodal ligand 4-(2′-pyridylmethyl)-4-azaheptane-1,7-diamine. Crystal structures of [CuLCl]ClO4 and [NiL(MeCN)2](ClO4)2

The tripodal ligand 4-(2′-pyridylmthyl)-4-azaheptane-1,7-diamine has been prepared by reaction of 2-aminemethyl pyridine with acrylonitrile, followed by the reduction of the nitrile groups. Copper(II), nickel(II), zinc(II), cobalt(III) and chromium(III) complexes of the ligand have been prepared and characterized and the crystal structures of the complexes [CuLCl]ClO₄ and [NiL(MeCN)₂](ClO₄)₂ determined. The copper complex is five coordinate with approximate square pyramidal stereochemistry with the apical position occupied by a primary amine donor. The nickel complex is octahedral with the pyridine nitrogen donor lying trans to an acetonitrile ligand.     

The development and application of guidance on equipment qualification of analytical instruments

 This paper describes the development of guidance for the equipment qualification (EQ) of analytical instruments. EQ is a formal process that provides documented evidence that an instrument is fit for its intended purpose and kept in a state of maintenance and calibration consistent with its use.     

Simple,Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel（Ⅱ）, Copper （Ⅱ）, Cobalt （Ⅱ）, and Iron （Ⅲ） with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.     

Electrochemically selective determination of dopamine in the presence of ascorbic and uric acids on the surface of the modified Nafion/single wall carbon nanotube/poly(3-methylthiophene) glassy carbon electrodes

A voltammetric method based on a combination of incorporated Nafion, single-walled carbon nanotubes and poly(3-methylthiophene) film-modified glassy carbon electrode (NF/SWCNT/PMT/GCE) has been successfully developed for selective determination of dopamine (DA) in the ternary mixture of dopamine, ascorbic acid (AA) and uric acid (UA) in 0.1M phosphate buffer solution (PBS) pH 4. It was shown that to detect DA from binary DA-AA mixture, the use of NF/PMT/GCE was sufficient, but to detect DA from ternary DA-AA-UA mixture NF/SWCNT/PMT/GCE was required. The later modified electrode exhibits superior electrocatalytic activity towards AA, DA and UA thanks to synergic effect of NF/SWCNT (combining unique properties of SWCNT such as high specific surface area, electrocatalytic and adsorptive properties, with the cation selectivity of NF). On the surface of NF/SWCNT/PMT/GCE AA, DA, UA were oxidized respectively at distinguishable potentials of 0.15, 0.37 and 0.53 V (vs. Ag/AgCl), to form well-defined and sharp peaks, making possible simultaneous determination of each compound. Also, it has several advantages, such as simple preparation method, high sensitivity, low detection limit and excellent reproducibility. Thus, the proposed NF/SWCNT/PMT/GCE could be advantageously employed for the determination of DA in real pharmaceutical formulations.     

Multi-instrument characterization of HiPIMS and DC magnetron sputtered tungsten and copper films

In this work, copper and tungsten were sputtered onto silicon wafers by direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS). The resulting films were characterized by energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and X-ray diffraction (XRD). By EDX and XPS, all the sputtered films showed only the expected metal peaks. By XPS, the surfaces sputtered by DCMS were richer in oxygen than those produced by HiPIMS. By AFM, the surfaces were quite smooth. The root mean square (RMS) roughness values are as follows: 0.83 nm (W, HiPIMS), 1.10 nm (W, DCMS), 0.85 nm (Cu, HiPIMS), and 1.78 nm (Cu, DCMS). By SEM, the HiPIMS films exhibited smaller grain sizes, which was confirmed by XRD. The crystallite sizes estimated by XRD are as follows: 4 nm (W, body-centered cubic, HiPIMS), 13 nm (W, body-centered cubic, DCMS), 7 nm (W, cubic, HiPIMS), 14 nm (W, cubic, DCMS), 25 nm (Cu, HiPIMS), and 35 nm (Cu, DCMS). By SE, the HiPIMS surfaces showed higher refractive indices, which suggested that they were denser and less oxidized than the DCMS surfaces.     

Simultaneous determination of mercury and arsenic by anodic stripping voltammetry

An electrochemical method for the simultaneous determinations of Hg^II concentration and total As^III and As^V concentration has been developed. The method does not require the additional preliminary step of the chemical reduction of As^V to As^III, or oxidation of As^III to As^V before stripping analysis takes place. Also, the method for the simultaneous determination of Hg^II concentration and As^III concentration is described. Measurements were performed in 0.1 M HCl using a gold-plated graphite electrode as sensor. Detection limits for both methods are below 0.4 ppb. Relative standard deviation did not exceed 15%. The possible interference by other trace metals was investigated. Analyses of natural water and industrial solutions were made using proposed methods and AAS. The t-test demonstrates that there was no significant difference between the results obtained with these methods. Proposed methods decrease the time of analysis because concentrations of the Hg^II and arsenic ions were measured simultaneously. Also, the removal of the additional step of chemical reduction of As^V to As^III or oxidation of As^III to As^V decreases analysis time, and also reduces the chance of contamination due to the use of additional reagents.