Ionic Liquid-Based Submerged Single Drop Microextraction: a New Method for the Determination of Aromatic Amines in Environmental Water Samples

A rapid and sensitive liquid chromatography–electrospray tandem mass spectrometry method, combined with solid-phase disk extraction cleanup, was developed and applied to the analysis of fifteen androgens in waste water. Compounds included androstenedione, androstanolone, boldenone, clostebol, danazol, 6-dehydronandrolone acetate, fluoxymesterone, methyltestosterone, nandrolone, nandrolone propionate, testosterone, testosterone acetate, testosterone propionate, trenbolone and trenbolone acetate, respectively. The overall method recoveries ranged from 78.0 to 107.7% and the limits of detection for the fifteen analytes determined in influent samples were between 0.5 and 4 ng L^?1. The analysis of residual androgens was carried out in waste water obtained from the Beijing area and five analytes (androstenedione, fluoxymesterone, methyltestosterone, testosterone and nandrolone) could be detected in levels ranging from 1.6–3.5, 7.6–66.7, 4.1–7.0, 1.2–4.3 and 1.7 ng L^?1, respectively.     

超高效液相色谱-串联质谱法测定动物肌肉组织和鸡蛋中残留的11种甾体激素类药物

建立了采用超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定猪、牛、羊和鸡肌肉组织及鸡蛋中睾酮、甲基睾酮、黄体酮、群勃龙、勃地龙、诺龙、美雄酮、司坦唑醇、丙酸诺龙、丙酸睾酮及苯丙酸诺龙等11种甾体激素多残留的分析方法。试样在碱性条件下用叔丁基甲醚提取,冷冻离心脱脂净化,以乙腈和甲酸水溶液为流动相,梯度洗脱,反相液相色谱分离。采用电喷雾离子化、多反应监测方式(MRM),对11种甾体激素同时进行定性定量测定。动物肌肉和鲜蛋中睾酮、甲基睾酮、勃地龙、美雄酮及司坦唑醇的检出限为0.3 μg/kg,群勃龙、诺龙、黄体酮、丙酸诺龙、丙酸睾酮及苯丙酸诺龙的检出限为0.4 μg/kg。在动物组织及鸡蛋中添加1,2及10 μg/kg 水平的药物回收试验中,睾酮、甲基睾酮、勃地龙、美雄酮及司坦唑醇的回收率均在62.3%～105%之间,相对标准偏差为0.5%～15%;群勃龙、诺龙、黄体酮、丙酸诺龙、丙酸睾酮及苯丙酸诺龙的回收率大于50.0%,相对标准偏差小于16%。11种甾体激素在1～100 μg/L范围内,线性关系良好,相关系数都大于0.99。该方法的样品前处理简单、快速,测定灵敏、准确,选择性好,可满足动物源食品中甾体激素类药物多残留的同时测定。     

高效液相色谱-串联质谱法同时检测鸡肉和鸡蛋中合成类固醇类激素和糖皮质激素

建立了鸡肉和鸡蛋中合成类固醇类激素(睾酮、甲基睾酮、群勃龙、勃地龙、诺龙、美雄酮、司坦唑醇、丙酸诺龙、丙酸睾酮及苯丙酸诺龙)和糖皮质类激素(泼尼松、泼尼松龙、地塞米松、氟氢可的松、甲基泼尼松、倍氯米松及氢化可的松)多残留的液相色谱-串联质谱(LC-MS/MS)检测方法.样品经乙腈超声提取,正己烷脱脂净化,以甲醇-甲酸水溶液为流动相,经C18柱分离后进行LC-MS/MS选择反应监测模式下的定性及定量分析.合成类固醇类激素采用正离子模式检测,糖皮质激素则采用负离子模式检测,正、负离子化模式一次进样同时检测.类固醇类和糖皮质类激素的定量检出限为0.5 μg/kg.在0.5、 1.0和5.0 μg/kg 3种浓度添加水平,上述激素的平均回收率为73.4%～108.9%;相对标准偏差为3.4%～13.4%.可实现样本灵敏、准确地定性定量分析.     

Targeted analysis and determination of β‐agonists,hormones, glucocorticoid and psychiatric drugs in feed by liquid chromatography with electrospray ionization tandem mass spectrometry

A comprehensive strategy combining a quantitative method was developed for 30 banned drugs including β‐agonists, hormones, glucocorticoid and psychiatric drugs in swine and chicken feeds. This rapid, simple and effective extraction method was based on matrix solid‐phase dispersion and electrospray ionization tandem mass spectrometry. The quantitative method was validated after previous statistical optimization of the main parameters of matrix solid‐phase dispersion. The limit of quantification of dopamine hydrochloride, chlormadinone acetate, melengestrol acetate, testosterone propionate, nandrolone and midazolam was 2 μg/kg and that of the other 24 drugs was 1 μg/kg. The recoveries of β‐agonists, hormones, glucocorticoid and psychiatric drugs spiked in swine and chicken feeds at a concentration range of 1–8 μg/kg were above 70.1% with inter‐day relative standard deviations less than 15.8%. The analytical strategy was applied to 100 feed samples collected from a local market in Wuhan (China). Clenbuterol, ractopamine and melengestrol acetate were identified and quantified at the level 0.2～3.5 μg/kg. The rapid and reliable method can be used to efficiently separate, characterize and quantify the residues of 30 banned drugs in swine and chicken feeds with advantages of simple pretreatment and environmental friendly nature.     

Hair analysis of anabolic steroids in connection with doping control-results from horse samples

Doping control of anabolic substances is normally carried out with urine samples taken from athletes and horses. Investigation of alternative specimens, e.g. hair samples, is restricted to special cases, but can also be worthwhile, in addition to urine analysis. Moreover, hair material is preferred in cases of limited availability or complicated collection of urine samples, e.g. from horses. In this work, possible ways of interpretation of analytical results in hair samples are discussed and illustrated by practical experiences. The results demonstrate the applicability of hair analysis to detect anabolic steroids and also to obtain further information about previous abuse. Moreover, the process of incorporation of steroids into hairs is described and the consequences on interpretation are discussed, e.g. on the retrospective estimation of the application date. The chosen examples deal with the detection of the anabolic agent testosterone propionate. Hair samples of an application study, as well as a control sample taken from a racing horse, were referred to. Hair material was investigated by a screening procedure including testosterone, nandrolone and several esters (testosterone propionate, phenylpropionate, decanoate, undecanoate, cypionate; nandrolone decanoate, dodecanoate and phenylpropionate; limits of detection (LODs) between 0.1 and 5.0 pg/mg). Confirmation of testosterone propionate (LOD 0.1 pg/mg) was carried out by an optimised sample preparation. Trimethylsilyl (TMS) and tert-butyl dimethylsilyl derivatives were detected by gas chromatography-high-resolution mass spectrometry (GC-HRMS) and gas chromatography-tandem mass spectrometry (GC-MS/MS).     

超高效液相色谱-串联质谱法同时测定鱼制品中残留的7种性激素

以电喷雾离子源(ESI)为电离源,在正离子采集模式下建立了鱼制品中7种性激素（甲基炔诺酮、甲基睾酮、丙酸睾酮、醋酸甲羟孕酮、醋酸甲地孕酮、醋酸氯地孕酮、诺龙）的超高效液相色谱-质谱/质谱(UPLC-MS/MS)检测方法。样品被酶解后用甲醇提取,提取液经氯化锌(ZnCl2)去脂、LC-C18和LC-NH2固相萃取柱净化、Waters ACQUITYTM UPLC BEH-C18色谱柱(100 mm×2.1 mm, 1.7 μm)分离,在多反应监测模式下进行UPLC-MS/MS分析。7种性激素的方法检出限(S/N=3)为0.08～0.17 μg/kg,定量限(S/N=10)为0.24～0.58 μg/kg。考察了内标法和基质匹配外标法对7种性激素进行定量的回收率与精密度: 添加水平为1, 4 μg/kg时,以内标法定量,7种性激素的平均回收率为76%～118%,相对标准偏差（RSD）为5.0%～11.3%;以基质匹配外标法定量,7种性激素的平均回收率为66%～94%,RSD为4.5%～10.7%。该结果表明两种方法均能够满足鱼制品中7种性激素的多残留检测要求。应用建立的方法对市售脱脂大黄鱼及烤鱼片进行检测,未发现7种目标违禁性激素。     

农产品中脱氧雪腐镰刀菌烯醇的表面增强拉曼检测

利用便携式拉曼光谱仪建立了一个快速筛查与检测谷物中真菌毒素脱氧雪腐镰刀菌烯醇(DON)的表面增强拉曼散射(SERS)方法。首先利用实验室前期开发的方法制备了具有高活性的水凝胶SERS芯片。该SERS芯片是将预先制备的高SERS活性的单层碳基点(CDs)包裹的银纳米颗粒团聚体(a-AgNPs/CDs)与聚乙烯醇(PVA)水溶液混合均匀后,再利用循环冷冻-解冻的物理交联法制备而成的。实验优化了影响水凝胶SERS芯片对DON的SERS响应的实验条件,包括溶剂、浸泡温度和浸泡时间。在最佳的SERS检测条件下(溶剂为水-乙醇(1:1, v/v),浸泡温度为40 ℃,浸泡时间为5 min), DON的线性响应范围为1~10000 μg/kg(相关系数(R²)=0.9967),检出限(LOD)为0.14 μg/kg,表明该SERS基底具有较高的灵敏度。得益于水凝胶特殊的孔径结构,实际样品基质中常见的糖、蛋白质、油脂、色素等干扰物质都被阻隔在水凝胶外。因此,在复杂样品检测中仅需要简单的提取,而不需要复杂的分离处理。将该方法用于小麦粉中DON的检测,所得回收率为97.3%~103%,相对标准偏差为4.2%~5.0%。实验结果表明所建立的检测DON的SERS方法具有响应范围宽、灵敏度高、重复性好、响应迅速、操作简单、抗干扰能力强等优点,这说明本实验室所构建的水凝胶SERS芯片在粮食中生物毒素的快速筛查与检测方面具有良好的应用潜力。     

高效液相色谱法同时测定牛肉组织中6种类固醇类激素类药物

建立了高效液相色谱法同时测定牛肉组织中勃地龙、诺龙、美雄酮、甲基睾酮、丙酸睾酮和丙酸诺龙的分析方法.试样经乙腈提取,冷冻离心脱脂净化,以甲醇-水为流动相,梯度洗脱,流速为1.0 mL/min.该方法的检出限(LOD)为0.0051～0.0086 mg/kg,定量限(LOQ)为0.0220～0.0287 mg/kg,在0...     

表面增强拉曼光谱在食品安全分析中的应用

拉曼光谱技术具有样品用量少、快速高效、无损分析等特点,表面增强拉曼光谱克服了常规拉曼光谱灵敏度低的缺点,可以获得更多物质结构信息,在现场快速筛查、检测和鉴别农兽残、限用或禁用添加剂分析检测中具有广阔的应用前景。本文综述了表面增强拉曼光谱在食品中农药残留、兽药残留和限/禁用添加剂检测中的研究进展,并展望了其发展前景。     

表面增强拉曼光谱对西地那非类药物的快速检测

采用表面增强拉曼光谱(SERS)技术并结合简单的前处理流程,对保健品样品中11种西地那非类药物进行了非定向快速筛查研究.结果表明,11种西地那非类药物可根据结构分为5类,类别之间SERS谱图差异显著;类别内SERS谱图具有共性特征,特征峰相对强度差异明显.实际样品的检测中,西地那非类药物的最低检出浓度约为0.05 mg/kg;前处理和测试的总时长约为3~5 min,且与检测目标物和样品无关.本方法高灵敏度、快速和非定向检测的设计理念为快速检测保健品中违禁添加药物提供了新思路和新方法.     

An integrated portable Raman sensor with nanofabricated gold bowtie array substrates for energetics detection

An integrated field-portable surface enhanced Raman scattering (SERS) sensing system has been developed and evaluated for quantitative analysis of energetics such as perchlorate (ClO(4)(-)) and trinitrotoluene (TNT) at environmentally relevant concentrations and conditions. The detection system consists of a portable Raman spectrometer equipped with an optical fiber probe that is coupled with novel elevated gold bowtie nanostructural arrays as a sensitive and reproducible SERS substrate. Using the standard addition technique, we show that ClO(4)(-) and TNT can be quantified at concentrations as low as 0.66 mg L(-1) (or ~6.6 μM) and 0.20 mg L(-1) (~0.9 μM), respectively, in groundwater samples collected from selected military sites. This research represents the first step toward the development of a field SERS sensor which may permit rapid, in situ screening and analysis for various applications including national security, chemical, biological and environmental detection.     

高效液相色谱串联质谱法同时测定水产品中24种性激素

建立了同时测定24种性激素的高效液相色谱串联质谱法,包括:睾酮、甲基睾酮、诺龙、苯丙酸诺龙、群勃龙、康力龙、勃地酮、雄烯二酮、美雄酮、炔诺酮、乙酸甲孕酮、乙酸甲羟孕酮、乙酸氯地孕酮、17α羟基孕酮、21α羟基孕酮、甲羟孕酮、左炔诺孕酮、雌酮、雌二醇、雌三醇、炔雌醇、己烷雌酚、己烯雌酚、双烯雌酚。乙酸乙酯提取2次,硅胶柱净化。采用甲醇、水作为流动相,经过CAPCELLPAK C18色谱柱分离后,采用APCI离子源,外标法定量。方法定量限为0.5～2μg/kg,加标回收率为80%～102%,相对标准偏差为6%～10%。方法实现了3类性激素的同时定量及确证分析。     

Bioorthogonal SERS Nanoprobes for Mulitplex Spectroscopic Detection,Tumor Cell Targeting,and Tissue Imaging

A surface‐enhanced Raman scattering (SERS) technique shows extraordinary features for a range of biological and biomedical applications. Herein, a series of novel bioorthogonal SERS nanoprobes were constructed with Gold nanoflower (AuNF) and Raman reporters, the signals of which were located in a Raman‐silent region of biological samples. AS1411 aptamer was also co‐conjugated with AuNF through a self‐assembled monolayer coverage strategy. Multiplex SERS imaging using these nanoprobes with three different bioorthogonal small‐molecule Raman reporters is successfully achieved with high multiplexing capacity in a biologically Raman‐silent region. These Raman nanoprobes co‐conjugated with AS1411 showed high affinity for tumor cells with overexpressed nucleolin and can be used for selective tumor cell screening and tissue imaging.     

A novel method for human gender classification using Raman spectroscopy of fingernail clippings

This paper illustrates a novel method for human gender classification by measuring the Raman spectrum of fingernail clippings. As Raman spectroscopy reveals the characteristics of vibrational frequencies of the fingernails, it provides unique chemical fingerprints that can be used to describe the molecular structure differences of fingernail between males and females. As the differences of Raman spectra of human fingernails are very subtle, they are enhanced by using a pattern recognition method. In the present study, a combination algorithm of principal component analysis (PCA) and support vector machines (SVM) was implemented to perform the data classification. This combined algorithm provides a classification accuracy of up to 90%. The success of this present method may be used as an alternative rapid tool to identify human gender in forensic applications.     

Identification of anabolic steroids and derivatives using bioassay-guided fractionation, UHPLC/TOFMS analysis and accurate mass database searching

Biological tests can be used to screen samples for large groups of compounds having a particular effect, but it is often difficult to identify a specific compound when a positive effect is observed. The identification of an unknown compound is a challenge for analytical chemistry in environmental analysis, food analysis, as well as in clinical and forensic toxicology. In this study bioassay-guided fractionation, ultra high performance liquid chromatography combined with time-of-flight mass spectrometry (UHPLC/TOFMS) and accurate mass database searching was tested to detect and identify unknown androgens. Herbal mixtures and sport supplements were tested using an androgen bioassay and modifications in sample preparations were carried out in order to activate inactive pro-androgens, androgen esters and conjugated androgens to enable their detection in the bioassay. Two of the four herbal mixtures tested positive and bioassay-guided fractionation followed by UHPLC/TOFMS of positive fractions resulted in the identification of nortestosterone phenylpropionate, testosterone cyclohexanecarboxylate and methyltestosterone. Three of the four sport supplements reacted toxic in the bioassay or gave inconclusive results and were further investigated using UHPLC/TOFMS in combination with data processing software and an accurate mass database having approximately 40,000 entries. This accurate mass database was derived from the PubChem database on the internet and coupled to the TOFMS software. This resulted in the tentative identification of several androgens, including methylboldenone, testosterone and the androgen esters methyltestosterone propionate or testosterone isobutyrate, testosterone buciclate and methylenetestosterone acetate. The study showed that bioassay-guided fractionation in combination with UHPLC/TOFMS analysis is a useful procedure to detect, isolate and identify unknown androgens in suspected samples. As an alternative, the use of data processing software in combination with an accurate mass database and coupled on-line with the TOFMS instrument software enabled the identification of androgens and androgen esters in the chromatogram even without bioassay-guided fractionation.     

表面增强拉曼光谱技术在食品安全检测中的应用

表面增强拉曼光谱是一种强有力的食品检验技术,当待测样品吸附于具有纳米量级粗糙度的金属结构表面时,样品分子的拉曼信号将得到极大的增强。该检测技术具有灵敏度高、响应迅速以及"指纹"识别等特点,在快速检测食品污染物等方面具有巨大的应用前景。该文介绍了表面增强拉曼光谱技术的发展历史、基本原理、基底分类以及联用技术,综述了该技术在重金属离子、兽药残留、农药残留、非法添加物、食源性致病微生物等方面的最新应用,最后提出了亟需解决的问题与未来的发展趋势(引用文献74篇)。     

Imaging and SERS Study of the Au Nanoparticles Interaction with HPV and Carcinogenic Cervical Tissues

In this work, gold NPs were prepared by the Turkevich method, and their interaction with HPV and cancerous cervical tissues were studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, confocal and multiphoton microscopy and SERS. The SEM images confirmed the presence and localization of the gold NPs inside of the two kinds of tissues. The light absorption of the gold NPs was at 520 nm. However, it was possible to obtain two-photon imaging (red emission region) of the gold NPs inside of the tissue, exciting the samples at 900 nm, observing the morphology of the tissues. The infrared absorption was probably due to the aggregation of gold NPs inside the tissues. Therefore, through the interaction of gold nanoparticles with the HPV and cancerous cervical tissues, a surface enhanced Raman spectroscopy (SERS) was obtained. As preliminary studies, having an average of 1000 Raman spectra per tissue, SERS signals showed changes between the HPV-infected and the carcinogenic tissues; these spectral signatures occurred mainly in the DNA bands, potentially offering a tool for the rapid screening of cancer.     

表面增强拉曼光谱技术在食品检测中的应用研究进展

食品污染是危害公众健康和安全的重要问题,探究灵敏、快速、简单的技术,以便在痕量水平上检测污染物,对保障食品质量安全和风险评价具有十分重要的意义.表面增强拉曼光谱(SERS)是利用光与金、银等纳米结构材料相互作用产生很强的表面等离子激元共振效应,可显著增强吸附在纳米结构表面上分子的拉曼信号,以超灵敏获取样品自身或拉曼探针...     

Time-dependent picture of the charge-transfer contributions to surface enhanced Raman spectroscopy

We reexamine the Herzberg-Teller theory of charge-transfer contributions to the theory of surface enhanced Raman scattering (SERS). In previous work, the Kramers-Heisenberg-Dirac framework was utilized to explain many of the observed features in SERS. However, recent experimental and theoretical developments suggest that we revise the theory to take advantage of the time-dependent picture of Raman scattering. Results are obtained for molecular adsorption on nanoparticles in both the strong confinement limit and the weak confinement limit. We show that the Herzberg-Teller contributions to the charge-transfer effect in SERS display a resonance at the molecule-to-metal or metal-to-molecule transition while retaining the selection rules associated with normal Raman spectroscopy (i.e., harmonic oscillator, as opposed to Franck-Condon overlaps). The charge-transfer contribution to the enhancement factor scales as Gamma(-4), where Gamma is the homogeneous linewidth of the charge-transfer transition, and thus is extremely sensitive to the magnitude of this parameter. We show that the Herzberg-Teller coupling term may be associated with the polaron-coupling constant of the surface phonon-electron interaction. A time-dependent expression for the Raman amplitude is developed, and we discuss the implications of these results for both metal and semiconductor nanoparticle surfaces.     

Surface enhanced Raman spectroscopy (SERS) for the discrimination of Arthrobacter strains based on variations in cell surface composition

Surface enhanced Raman spectroscopy (SERS) is a rapid and highly sensitive spectroscopic technique that has the potential to measure chemical changes in bacterial cell surface in response to environmental changes. The objective of this study was to determine whether SERS had sufficient resolution to differentiate closely related bacteria within a genus grown on solid and liquid medium, and a single Arthrobacter strain grown in multiple chromate concentrations. Fourteen closely related Arthrobacter strains, based on their 16S rRNA gene sequences, were used in this study. After performing principal component analysis in conjunction with Linear Discriminant Analysis, we used a novel, adapted cross-validation method, which more faithfully models the classification of spectra. All fourteen strains could be classified with up to 97% accuracy. The hierarchical trees comparing SERS spectra from the liquid and solid media datasets were different. Additionally, hierarchical trees created from the Raman data were different from those obtained using 16S rRNA gene sequences (a phylogenetic measure). A single bacterial strain grown on solid media culture with three different chromate levels also showed significant spectral distinction at discrete points identified by the new Elastic Net regularized regression method demonstrating the ability of SERS to detect environmentally induced changes in cell surface composition. This study demonstrates that SERS is effective in distinguishing between a large number of very closely related Arthrobacter strains and could be a valuable tool for rapid monitoring and characterization of phenotypic variations in a single population in response to environmental conditions.