动物源性食品大环内酯类抗生素残留检测样品前处理技术研究综述

大环内酯类抗生素在全球饲料添加剂中仅次于四环素类抗生素,使用广泛,可通过食物链进入人体,对人体健康造成影响.因此,开发相应的残留检测技术有重要的社会意义.而样品前处理技术的发展与革新对抗生素残留检测技术发展具有巨大的推动作用.本文综述了近年来动物源性食品大环内酯类抗生素残留检测样品前处理技术研究进展,并对样品前处理技术在动物源性食品大环内酯类抗生素残留检测中的应用前景进行了展望,以期为相关研究者提供技术参考.     

改性植物生物炭去除水中四环素类抗生素的研究进展

四环素类抗生素滥用和缺乏有效去除技术导致广泛残留并诱导产生耐药细菌,已成为世界环境问题之一.植物生物炭具有来源广、成本低、易制备、资源有效利用和环境友好等优点,在环境修复领域,特别是抗生素污染物去除方面备受关注.本文综述了改性植物生物炭对四环素类抗生素的去除效果,讨论环境因素对改性生物炭性能的影响并深入探讨去除机制,分...     

Ni电极电化学流通池检测四环素类药品的研究

比较Au、GC和Ni电极对四环素的电化学响应,讨论了纯Ni电极对四环素的电催化氧化特性,提出以纯Ni为工作电极的电化学流通池,优化结构,建立了测定四环素类抗生素的电化学流通池安培检测法.该方法对四环素、土霉素和强力霉素都有较高的响应灵敏度,线性范围0.1～15mg/L.最低检出限分别为35、45和43μg/L.用此方法可以直接测定四环素类药品的含量.     

液相色谱-串联质谱法测定动物性食品中20种抗生素类药物残留

建立了一种专属、灵敏的方法用于同时检测动物性食品中β-内酰胺类青霉素类抗生素、大环内酯类抗生素、四环族抗生素和林可胺类共20 种抗生素药物残留.首先对动物性食品中的抗生素类药物进行提取,再经HLB固相萃取柱净化,采用电喷雾离子源,以正离子检测方式进行质谱分析.实验结果表明,在10-200 μg/L质量浓度范围内上述20...     

水热合成具有分级结构的钨酸铋纳米花及其光催化降解四环素性能

采用一种简单的无模板水热合成法制备了具有分级结构的钨酸铋纳米花,并将钨酸铋纳米花材料应用于可见光催化去除水中的四环素类抗生素。通过X射线粉末衍射、扫描电镜、透射电镜、紫外固体漫反射、比表面分析等一系列物理表征对光催化剂和催化反应体系进行了表征。研究结果表明钨酸铋纳米光催化剂对四环素类抗生素（四环素和土霉素）均具有良好的降解能力。此外,催化剂对碱性溶液中四环素的降解效率普遍较高,且该催化剂表现出良好的循环稳定性。     

微流动注射芯片化学发光法检测鱼虾中的四环素

四环素(tetracycline,TC)是广谱类抗生素,由于价格低廉,防病和抗病能力强,被许多人用于食用动物和海洋生物的养殖中,由此造成动物组织中四环素的残留,人们长期食用这种动物及制品,会对人类健康构成严重的威胁。分析四环素类抗生素残留量的方法包括微生物法、紫外法、薄层色谱法     

五种四环类抗生素的固体表面荧光法的研究

五种四环类抗生素的固体表面荧光法的研究解宏智，董川，刘长松，赵丽霞，杜学勤（山西大学化学系，太原，０３０００６）关键词固体表面荧光，碱性降解，四环类抗生素四环类抗生素的亲癌作用使其成为诊断和治疗肿瘤的荧光探针［１］，基于该类抗生素碱性降解速率的差异［...     

RGO/Fe_2O_3的制备及其对四环素的吸附性能研究

采用改进的hummer法制备氧化石墨烯,以氧化石墨烯(GO)为前驱体,六水合氯化铁为铁源,通过溶剂热法一步合成RGO/Fe_2O_3材料。使用X射线衍射、热重、红外光谱法等对所得材料进行了表征。考察了此材料对四环类抗生素的吸附性能。结果表明,该材料对四环素类抗生素的吸附量随溶液初始浓度和温度的升高而增加。当初始浓度大于6 mmol·L-1时吸附量趋于平衡。所得材料对四环素(TC)的静态饱和容量为783.53 mg·g~(-1),吸附过程对Langmuir以及Freundlich方程均呈现出的拟合度良好。将RGO/Fe_2O_3作为固相萃取剂,对牛奶样品进行加标回收实验,平均回收率为99.1%~99.6%,相对标准偏差(RSD)为5.2%~6.0%,该吸附材料RGO/Fe_2O_3可以用于四环素类抗生素的富集分离测定,结果稳定性好,并且能重复使用。     

日本拟调整进口食品、农产品药残标准

<正>日本此次对食品、农产品药残标准进行调整,有放宽的部分,例如参照美国标准,放宽了大白菜、花菜、西兰花中烯酰吗啉的最高残留限量(MRL值),但增加了我国出口日本数量较大的菠菜、芹菜、蘑菇中MRL值,还将干辣椒设为强制检测项目;对鱼虾贝类增加灭藻醌残留要求,并对所有产品提高了残留限量标准;对杏子、樱桃等增加了四环素类抗生素限量要求;对所有蔬菜、水果增加了吡唑酰胺的限量要求。日本对瘦肉精等调整了检测方法,调整后检测方法要     

高效液相色谱测定盐酸金霉素及其杂质

金霉素属于四环素类抗生素,在金霉素的生产和贮存期间产生一些四环素类的副产物,有的有一定药效,有的是有害物质。目前我国对金霉素的检验采用微生物效价测定法和薄层色谱法。国外近年内有用高效液相色谱法,但至今未见公开报道。经过一段时间的摸索,我们建立了高效液相色谱法测定金霉素及其杂质的方法,并发现了以前未知的杂质。     

红景天苷及其酯化产物的ESI MS和MS/MS裂解途径

糖苷广泛存在于自然界中,常以糖苷酯形式存在,这有效地提高了它们的酯溶性,增加它们在肠内和胞内的吸收[1-3]。红景天苷是一种具有抗疲劳、抗辐射、抗缺氧、提高记忆、延缓衰老等药理活性的天然糖苷[4-8],在此先导化合物的基础上合成了各种红景天苷酯。本文对这类红景天苷酯的E     

MS/MS: Cloned mass spectrometers

Coupling mass spectrometers in tandem (MS/MS) can greatly increase the specificity of MS analysis without significantly decreasing its unusual sensitivity and speed, particularly for trace levels of preselected compounds in complex organic mixtures. MS/MS also gives more detailed structural information for larger organic molecules in submicrogram quantities.     

Dual parallel electrospray ionization and atmospheric pressure chemical ionization mass spectrometry (MS), MS/MS and MS/MS/MS for the analysis of triacylglycerols and triacylglycerol oxidation products

Two mass spectrometers, in parallel, were employed simultaneously for analysis of triacylglycerols in canola oil, for analysis of triolein oxidation products, and for analysis of triacylglycerol positional isomers separated using reversed-phase high-performance liquid chromatography. A triple quadrupole mass spectrometer was interfaced via an atmospheric pressure chemical ionization (APCI) interface to two reversed-phase liquid chromatographic columns in series. An ion trap mass spectrometer was coupled to the same two columns using an electrospray ionization (ESI) interface, with ammonium formate added as electrolyte. Electrospray ionization mass spectrometry (ESI-MS) under these conditions produced abundant ammonium adduct ions from triacylglycerols, which were then fragmented to produce MS/MS spectra and then fragmented further to produce MS/MS/MS spectra. ESI-MS/MS of the ammoniated adduct ions gave product ion mass spectra which were similar to mass spectra obtained by APCI-MS. ESI-MS/MS produced diacylglycerol fragment ions, and additional fragmentation (MS/MS/MS) produced [RCO](+) (acylium) ions, [RCOO+58](+) ions, and other related ions which allowed assignment of individual acyl chain identities. APCI-MS of triacylglycerol oxidation products produced spectra like those reported previously using APCI-MS. APCI-MS/MS produced ions related to individual fatty acid chains. ESI-MS of triacylglycerol oxidation products produced abundant ammonium adduct ions, even for those molecules which previously produced little or no intact molecular ions under APCI-MS conditions. Fragmentation (MS/MS) of the [M+NH(4)](+) ions produced results similar to those obtained by APCI-MS. Further fragmentation (MS/MS/MS) of the diacylglycerol fragments of oxidation products provided information on the oxidized individual fatty acyl chains. ESI-MS and APCI-MS were found to be complementary techniques, which together contributed to a better understanding of the identities of the products formed by oxidation of triacylglycerols.     

LC/MS and LC/MS/MS determination of protein tryptic digests

Tryptic digests were analyzed by means of online microbore liquid chromatography combined with mass spectrometry (LC/MS) for some common proteins. Following conventional enzymatic digestion with trypsin, the freeze-dried residues were dissolved in high-performance liquid chromatography (HPLC) eluent and subjected to gradient reversed-phase microbore HPLC separation with mass spectrometric detection. The latter was done in the full-scan single or tandem (MS/MS) mass spectrometry mode. The formation of gas-phase ions from dissolved analytes was accomplished at atmospheric pressure by pneumatically assisted electrospray (ion spray) ionization. This produced field-assisted ion evaporation of dissolved ions, which could then be mass-analyzed for molecular mass or structure. In the full-scan LC/MS mode, the masses for the peptide fragments in the tryptic digests can be determined as either their singly or multiply charged ions. When the molecular weights of the peptides lie outside the mass range of the mass spectrometer, the multiply charged feature of these experimental conditions still provides reliable molecular weight determinations. In addition, collision-activated dissociation (CAD) on selected peptide precursor ions provides online LC/MS/MS sequence information for the tryptic fragments. Results are shown for the tryptic digests of horse heart cytochrome c, bovine β-lactoglobulin A, and bovine β-lactoglobulin B.     

Analysis of MS/MS fragmentation of taxoids

The fragmentation pathways of seven types of taxoids were investigated by using a LC-MS/MS method, namely: (1) neutral taxoids with a C-4(20) double bond; (2) taxoids with a C-4(20) double bond and oxygenation at C-14; (3) 5-cinnamoyl taxoids with a C-4(20) double bond; (4) a basic taxoid with a C-4(20) double bond; (5) a taxoid with a C-4(20) epoxide; (6) taxoids with an oxetane ring; and (7) taxoids with an oxetane ring and a phenylisoserine C-13 side chain. Depending on the class of core structure and the substitution pattern, each taxoid gave either the molecular adduct ion [M+NH4]+ or [M+H]+. In the MS/MS, the molecular adduct ion gave characteristic product ions corresponding to the loss of water, acetic acid, benzoic acid, and cinnamic acid or the phenylisoserine group. These could reflect the difference of the substitutions and structural modifications and should be utilized for the structure elucidation oftaxoids by LC-MS.     

Analytical performance of the various acquisition modes in Orbitrap MS and MS/MS

Quadrupole Orbitrap instruments (Q Orbitrap) permit high‐resolution mass spectrometry‐based full scan acquisitions and have a number of acquisition modes where the quadrupole isolates a particular mass range prior to a possible fragmentation and high‐resolution mass spectrometry‐based acquisition. Selecting the proper acquisition mode(s) is essential if trace analytes are to be quantified in complex matrix extracts. Depending on the particular requirements, such as sensitivity, selectivity of detection, linear dynamic range, and speed of analysis, different acquisition modes may have to be chosen. This is particularly important in the field of multi‐residue analysis (eg, pesticides or veterinary drugs in food samples) where a large number of analytes within a complex matrix have to be detected and reliably quantified. Meeting the specific detection and quantification performance criteria for every targeted compound may be challenging. It is the aim of this paper to describe the strengths and the limitations of the currently available Q Orbitrap acquisition modes. In addition, the incorporation of targeted acquisitions between full scan experiments is discussed. This approach is intended to integrate compounds that require an additional degree of sensitivity or selectivity into multi‐residue methods.     

Selective detection and identification of phosphopeptides by dansyl MS/MS/MS fragmentation

Protein phosphorylation regulates many cellular processes and pathways, such as cell cycle progression, signal transduction cascades and gene expression. Selective detection of phosphopeptides from proteolytic digests is a challenging and highly relevant task in many proteomics applications. Often phosphopeptides are present in small amounts and need selective isolation or enrichment before identification. Here we report a novel approach to label selectively phospho-Ser/-Thr residues by exploiting the features of a novel linear ion trap mass spectrometer. Using dansyl labelling and MS3 fragmentation, we developed a method useful for the large-scale proteomic profiling of phosphorylation sites. The new residues in the sequence were stable and easily identifiable under general conditions for tandem mass spectrometric sequencing.     

An impulse-driven liquid-droplet deposition interface for combining LC with MALDI MS and MS/MS

A simple and robust impulse-driven droplet deposition system was developed for off-line liquid chromatography matrix-assisted laser desorption ionization mass spectrometry (LC-MALDI MS). The system uses a solenoid operated with a pulsed voltage power supply to generate impulses that dislodge the hanging droplets from the LC outlet directly to a MALDI plate via a momentum transfer process. There is no contact between the LC outlet and the collection surface. The system is compatible with solvents of varying polarity and viscosity, and accommodates the use of hydrophobic and hydrophilic MALDI matrices. MALDI spots are produced on-line with the separation, and do not require further processing before MS analysis. It is shown that high quality MALDI spectra from 5 fmol of pyro-Glu-fibrinopeptide deposition after LC separation could be obtained using the device, indicating that there was no sample loss in the interface. To demonstrate the analytical performance of the system as a proteome analysis tool, a range of BSA digest concentrations covering about 3 orders of magnitude, from 5 fmol to 1 pmol, were analyzed by LC-MALDI quadrupole time-of-flight MS, yielding 6 and 57% amino acid sequence coverage, respectively. In addition, a complex protein mixture of an E. coli cell extract was tryptically digested and analyzed by LC-MALDI MS, resulting in the detection of a total of 409 unique peptides from 100 fractions of 15-s intervals.