热解吸-电喷雾离子源-三重四极杆质谱法快速筛查火锅底料和肉汤中非法添加罂粟壳

通过简单的金属探针直接接触火锅底料和肉汤表面采集待测物,经热解吸离子源进一步热解吸和电喷雾离子化,最终进入三重四极杆质谱检测器在多反应监测模式下进行定性分析,实现了火锅底料和肉汤中罂粟壳的现场实时快速检测。结果表明,设置热解吸温度为260℃,以0.1%甲酸水溶液（含10 mmol/L甲酸铵-乙腈（1:1,v/v）作为注射溶剂、注射泵流速为200 μL/h时,仪器响应值最优,灵敏度最高;5种生物碱中罂粟碱、那可丁、蒂巴因在火锅底料和肉汤中的检出限均为2 μg/kg,可待因、吗啡在火锅底料中的检出限为10 μg/kg,在肉汤中的检出限为5 μg/kg。该法与罂粟壳胶体金卡片快检试剂盒相比,灵敏度具有明显优势。应用该法对50批次市售火锅底料、肉汤等样品进行检测,发现1批次鸡汤含有那可丁、罂粟碱、蒂巴因和吗啡4种生物碱,与高效液相色谱-三重四极杆质谱法的检测结果一致。由此说明该方法具有无需样品制备和色谱分离的特点,是一种快速、绿色、环保的分析方法,能够满足对食品中罂粟壳的快速定性分析。     

超高效液相色谱-串联质谱法测定食品中4种罂粟壳生物碱

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)测定食品中可卡因、可待因、吗啡、盐酸罂粟碱的检测方法.样品经氨化甲醇提取,采用Capcell Pak C_(18)(250 mm×2.0 mm,MGⅡ 5μm)色谱柱,以色谱纯乙腈为流动相A,以20 mmol/L乙酸铵和0.1%甲酸缓冲液为流动相B,进行梯度洗脱.在优选条件下,可待因、吗啡方法线性范围为5.0~50.0μg/L,可卡因、盐酸罂粟碱的方法线性范围为1.0~20.0μg/L,相关系数均大于0.999,方法检出限在0.1~0.8μg/kg之间,平均回收率为76.0%~111.2%,相对标准偏差RSD低于10%.     

四极杆-轨道阱高分辨质谱联用技术用于食品中罂粟壳特征成份的确证

采用液相色谱-四极杆/轨道阱高分辨质谱(Q-Exactive)技术,建立了火锅底料、食品调味料、烤肉、凉皮中吗啡、可待因、蒂巴因、罂粟碱、那可丁5种生物碱的确证方法。样品在稀盐酸溶液中超声提取,经三氯甲烷除脂,离子交换固相萃取柱净化,氨化甲醇-乙酸乙酯洗脱,Accucore a Q色谱柱分离,电喷雾模式下通过静电场轨道阱全扫描得到5种生物碱的准分子离子峰,同时设定阈值自动触发二级质谱进行定性确证,同位素内标法定量,实现了食品中罂粟壳主要特征成份的筛查,同时对5种生物碱的特征子离子裂解方式进行研究。在最佳实验条件下,5种生物碱的质谱扫描质量精度误差小于5 ppm。吗啡的定量下限(LOQ)为2.0μg/kg,可待因为0.2μg/kg,罂粟碱、蒂巴因和那可丁为0.1μg/kg。分析物浓度与对应峰面积呈良好的线性关系(r20.999),方法回收率为63.4%~112.8%,相对标准偏差(RSD)为5.5%~13.6%。将该方法应用于多种实际样品分析,其定量结果准确,定性可靠。     

同位素内标-多反应监测同步在线质谱全扫描确证火锅料中罂粟壳成分

建立了高效液相色谱-三重四极杆线性离子阱质谱测定火锅料中吗啡、可待因、蒂巴因、罂粟碱、那可丁等5种生物碱残留的确证方法。样品采用稀盐酸加热提取,正己烷除脂,阳离子混合机理固相萃取柱净化,5%氨化乙酸乙酯-甲醇洗脱,PAK ST色谱柱分离,5 mmol/L乙酸铵甲醇溶液-10 mmol/L乙酸铵水溶液(pH 3.6)作为流动相洗脱,电喷雾正离子模式下多反应监测同步增强子离子在线全扫描(EPI)。在该实验条件下,5种生物碱的LOD在0.05~0.5 μg/kg之间,增强型子离子全扫描水平限和LOQ在0.2~2 μg/kg之间,方法回收率为64.2%~110.6%, RSD为4.2%~12.5%。阳性样品的定性确证需采用其子离子全扫描质谱图与标准图库中子离子质谱图检索匹配。经测定多种火锅料,表明本方法操作简单、测定结果准确,可用于火锅料中5种生物碱残留的阳性结果确证分析。     

基于轨道阱高分辨质谱联用技术建立食品中罂粟壳生物碱的快速筛查方法

本文采用超高效液相色谱-四极杆/轨道阱高分辨质谱法,建立食品中5种罂粟壳生物碱的快速筛查方法,同时建立质谱数据库,摆脱标准品依赖,实现高通量筛查。食品中5种罂粟壳生物碱采用优化后的前处理方法进行提取,HILIC色谱柱实现分离,采用全扫描自动触发二级扫描模式(Full MS/dd MS²)对吗啡、可待因、罂粟碱、那可丁和蒂巴因进行检测。方法线性范围1～100 ng/mL,相关系数大于0.99,检出限0.1～0.5μg/kg,回收率69.9%～118.7%,相对标准偏差3.2%～15.4%。方法前处理简便、检测灵敏度高、重现性好,可用于食品中罂粟壳生物碱的快速筛查。     

固相萃取/HPLC-MS/MS检测食品中吗啡等五种罂粟壳生物碱残留

建立了同时检测食品中非法添加罂粟壳所产生的吗啡、可待因、蒂巴因、那可汀、罂粟碱残留量的固相萃取/HPLC-MS/MS方法。样品用体积分数1%三氯乙酸与乙腈混合液提取、正已烷脱脂后的净化液直接用PCX固相萃取柱净化。以乙腈-10 mmol/L乙酸铵为流动相、梯度洗脱、CR色谱柱分离、液相色谱-串联质谱联用仪检测,ESI(+)SRM模式、标准曲线外标法检测吗啡等5种生物碱。化合物标准曲线相关系数均≥0.996,定量限均为0.5,1.0,5.0μg/kg,3个浓度添加水平的回收率在62.2%~117.9%之间,相对标准偏差在5.1%~17%(n=6)之间。     

液相色谱-串联四极杆质谱法测定罂粟壳主要成分在止咳药中的含量

采用液相色谱-电喷雾串联四极杆质谱仪,用多离子反应检测(MRM)定量法检测,通过对样品SPE净化预处理、色谱条件、质谱参数等的优化选择和方法学验证,建立了定量检测止咳药中的罂粟壳含量的理想方法。吗啡、可待因、罂粟碱、那可丁的母离子质荷比分别为286.2、300.2、340.7、413.4、289.3;定量用子离子分别为165.0、215.1、202.5、324.7、220.0、201.1,另一组子离子分别为181.1、165.1、324.7、353.1、165.0。本方法灵敏度高、操作简单、定量准确。吗啡、可待因、罂粟碱、那可丁的检出限LOD分别为0.073、0.024、0.003和0.0009μg/L(进样量10μL),定量限LOQ分别是0.24、0.08、0.01和0.003μg/L。回收率为95%~110%。     

超高效液相色谱-串联质谱法快速测定镇咳祛痰药中阿片类物质的含量

建立了镇咳祛痰药中吗啡、可待因、海洛因、蒂巴因、罂粟碱、那可汀6种阿片类物质含量的LCM S/M S快速测定方法。药品经超声浸取,甲醇稀释过滤后经Waters C₁₈柱分离,以乙腈和10 mmol/L乙酸铵(含0.1%甲酸)溶液进行梯度洗脱,采用电喷雾正离子化(ESI+)、多反应监测模式进行测定。6种阿片类物质在相应的线性范围内线性均良好(r> 0.9995),检出限为吗啡0.2 ng/mL、可待因0.1 ng/mL、海洛因0.03 ng/mL、蒂巴因0.07 ng/mL、罂粟碱0.002 ng/mL、那可汀0.001 ng/mL。日内精密度为0.89%~2.5%,日间精密度为1.5%~5.5%,加标回收率在77.7%~90.5%之间。方法适用于镇咳祛痰药中吗啡、可待因、海洛因、蒂巴因、罂粟碱、那可汀6种阿片类物质的定性定量检测及质量控制。     

TurboFlow在线净化-超高效液相色谱-三重四极杆/复合线性离子阱质谱法快速测定食品中违禁添加的罂粟壳

采用在线净化-超高效液相色谱-三重四极杆/复合线性离子阱质谱(TF-UPLC-QTRAP MS)技术,建立了食品中吗啡、可待因、蒂巴因、罂粟碱、那可丁和原阿片碱6种罂粟壳标志物的快速确证检测方法。样品经0.10 mol/L盐酸提取、正己烷脱脂后,直接注入TF-UPLC-QTRAP MS进行分析。对影响净化的条件如TF-净化柱、流动相、洗脱溶液等条件进行了优化。确定以TurboFlow Cyclone MCX柱作为净化柱,Acquity BEH C_(18)柱为分析柱,甲醇-0.05%(体积分数)氨水溶液作为流动相,电喷雾正离子模式下多反应监测-触发增强子离子(MRM-IDA-EPI)扫描方式检测,以溶剂标准内标法定量。方法的检出限为0.05~0.5μg/kg,定量限为0.2~2μg/kg。平均加标回收率为81.1%~98.6%,相对标准偏差为2.9%~15.7%(n=6)。该方法灵敏、准确,适用于食品中非法添加罂粟壳的检测,已应用于实际样品的测定。     

酶联免疫法检测火锅底料及小吃类食品中吗啡及可待因

通过对吗啡分子结构进行改造,制备了吗啡半抗原及人工抗原,免疫动物,制备了吗啡的单克隆抗体,建立了吗啡及可待因间接竞争酶联免疫检测方法。方法的IC50为0.7μg/L,检测范围为0.3~24.3μg/L,标准曲线R~2为0.998,检测限5μg/kg,检测时间45 min。在5,10,20μg/kg添加水平火锅底料、辣椒酱样品中平均添加回收率为77%~118%,RSD小于12%,经t检验,该法与上海地标法无明显差异。     

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     

Studies on the Formation of Catalytically Active PGM Nanoparticles from Model Solutions as a Basis for the Recycling of Spent Catalysts

The paper presents basic studies on the precipitation of platinum, palladium, rhodium, and ruthenium nanoparticles from model acidic solutions using sodium borohydride, ascorbic acid, and sodium formate as reducing agents and polyvinylpyrrolidone as a stabilizing agent. The size of the obtained PGM particles after precipitation with NaBH₄ solution does not exceed 55 nm. NaBH₄ is an efficient reducer; the precipitation yields for Pt, Pd, Ru, Rh are 75, 90, 65 and 85%, respectively. By precipitation with ascorbic acid, it is possible to efficiently separate Pt, Rh, and Ru from Pd from the two-component mixtures. The obtained Pt, Pd, and Rh precipitates have the catalytic ability of the catalytic reaction of p-nitrophenol to p-aminophenol. The morphological characteristic of the PGM precipitates was analyzed by AFM, SEM-EDS, and TEM.     

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.     

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.     

Sample preparation and current applications of liquid chromatography for the determination of non-structural carbohydrates in plants

This article summarizes the current methods of determination of non-structural carbohydrates (NSCs) in plant samples based on liquid chromatography (LC). NSCs comprise several types of carbohydrates: sugar alcohols (e.g., sorbitol), monosaccharides (e.g., glucose and fructose), disaccharides (e.g., sucrose), oligosaccharides (e.g., raffinose) and polysaccharides [e.g., starch and polyfructans (e.g., inulin)]. NSCs are important in plant metabolism and have to be strictly distinguished from all sorts of structural carbohydrates (e.g., polysaccharide cellulose) that make up the backbone of the plants. Consequently, preservation of structural carbohydrates is a crucial step during sample preparation for NSC determination and is therefore addressed.Sugar alcohols, monosaccharides, disaccharides and those oligosaccharides that are easily soluble in polar solvents can be analyzed directly by high-performance LC. They are also referred to as free carbohydrates (FCs).However, polysaccharides are generally submitted to hydrolyzation into monomers prior to their quantitative analysis. This can be done either chemically, using acids, or enzymatically - both methods are discussed. For identification and quantification of the NSCs after LC separation, the following detectors are used: pulsed amperometry, refractive index, evaporate light scattering and finally, mass spectrometry.     

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.     

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.