大孔弱酸树脂对妥布霉素纯化的工艺研究

工业生产中妥布霉素发酵液粗提物的纯度只能达到50~60%,通常采用强酸树脂进行纯化,但纯化纯度很难达到国家药典要求。本文比较了5种阳离子交换树脂对妥布霉素的吸附性能,利用静态吸附与动态吸附实验优选出了大孔弱酸树脂HZ-3B,并对其纯化妥布霉素工艺进行了进一步的优化:选用浓度为5mg/m L,pH值为6.8~7.2的妥布霉素溶液以9BV/h的流速进行上样,上样200BV;然后利用0.125mol/L的氨水溶液作为解吸液,以6BV/h的流速进行解吸,合并解吸液。HPLC分析结果显示,妥布霉素纯度由50~60%提升到了97.15%,收率为89.52%,且无其他氨基糖苷类抗生素杂质,达到了国家药典的要求。     

高效液相色谱-串联质谱法检测乳制品中10种氨基糖苷类抗生素残留

建立了乳制品中链霉素、双氢链霉素、新霉素、卡那霉素、妥布霉素、庆大霉素、安普霉素、潮霉素B、巴龙霉素、阿米卡星等10种氨基糖苷类抗生素(aminoglycosides, AGs)残留的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。乳制品提取液经亲水-亲脂平衡(hydrophilic- lipophilic balance, HLB)柱净化后,采用反相离子对高效液相色谱分离,电喷雾串联四极杆质谱检测。对样品前处理条件、液相色谱流动相以及质谱条件进行了优化。结果表明: 10种AGs在20～1000 μg/L范围内定量离子的峰面积和样品的质量浓度之间有很好的线性关系;在乳制品中的加标回收率为71.2%～101.7%,相对标准偏差为3.4%～13.8%。该方法简便、灵敏、准确,可用于乳制品中多种AGs残留的同时检测。     

分子印迹聚合物固相萃取-超高效液相色谱-串联质谱法检测水产品中11种氨基糖苷类药物残留

建立了水产品中巴龙霉素、壮观霉素、妥布霉素、庆大霉素、卡那霉素、潮霉素B、安普霉素、链霉素、双氢链霉素、丁胺卡那霉素和新霉素共11种氨基糖苷类药物(AGs)残留的超高效液相色谱-串联质谱(UPLCMS/MS)检测方法。样品经磷酸盐缓冲液提取,分子印迹聚合物(MIP)固相萃取柱净化,Obelisc R色谱柱分离,采用超高效液相色谱-串联质谱仪进行测定。方法检出限(LOD,S/N≥3)为1.0~10.0μg/kg,定量限(LOQ,S/N≥10)为2.0~20.0μg/kg。11种AGs在1.0~1000μg/kg范围内线性关系良好(R20.994),在水产品中加标回收率为78.4%~109.6%,相对标准偏差(RSD,n=6)为2.3%~14.9%。本方法灵敏度高,且可实现11种AGs同时检测。     

高效液相色谱-脉冲积分安培电化学检测牛奶中的妥布霉素

采用C18键合硅胶柱和脉冲积分安培电化学检测器对妥布霉素样品进行了分离检测。对两种检测电位波形进行了对比，并选取了表现优良的检测电位。方法对妥布霉素的检出限19μg／L，在0．1～25mg／L范围内表现良好线性（r=0．9999）。该方法应用于市售鲜奶的检测，妥布霉素的回收率为98％。     

鲁米诺-过渡金属超常氧化态配合物化学发光体系测定氨基糖苷类抗生素

研究发现过渡金属超常氧化态配合物(二羟基二过碘酸根合铜(Ⅲ)配离子(DPC)、二羟基二过碘酸根合银(Ⅲ)配离子(DPA)和二羟基二过碘酸根合镍(Ⅳ)配离子(DPN))在碱性条件下可以氧化鲁米诺而产生化学发光,氨基糖苷类抗生素对该化学发光体系有增敏作用。以DPC为例研究了氨基糖苷类抗生素——托普霉素对该体系的增敏作用,建立了测定血清中托普霉素含量的新方法。考察了溶液酸碱度和化学发光试剂对化学发光强度的影响,在最佳实验条件下,托普霉素浓度在6.0×10-8~2.0×10-6g/mL范围内与化学发光强度呈良好的线性关系,方法的检出限(3σ)为1.5×10-8g/mL,对浓度为5.0×10-7g/mL的托普霉素溶液连续测定7次,相对标准偏差为2.7%。该方法用于血清中托普霉素含量的测定,结果令人满意。     

混合型离子交换液相色谱-串联质谱法检测鸡蛋中10种氨基糖苷类药物残留

该研究系统地优化了样品前处理过程及仪器分析中影响氨基糖苷残留分析准确度与灵敏度的各主要因素,建立了鸡蛋中10种氨基糖苷类药物(链霉素、双氢链霉素、潮霉素B、卡那霉素、阿米卡星、妥布霉素、安普霉素、大观霉素、新霉素、庆大霉素)残留量的混合型离子交换液相色谱-串联质谱分析方法。样品经10 mmol/L乙酸铵缓冲溶液(含0.4 mmol/L EDTA和50 g/L三氯乙酸)超声提取,调节pH至6~7后,经PRiME HLB固相萃取柱富集净化,采用SIELC Obelisc R色谱柱分离,以乙腈和1.0%(v/v)甲酸水溶液(含1 mmol/L甲酸铵)为流动相进行梯度洗脱,在正离子、多反应监测模式下经串联质谱仪测定,外标法定量。该方法在5~200 μg/L质量浓度范围内线性关系良好,相关系数(r²)均大于0.99;方法的检出限(LOD, S/N≥3)为2~5 μg/kg,定量限(LOQ, S/N≥10)为5~10 μg/kg。在空白鸡蛋中进行LOQ、20 μg/kg、100 μg/kg 3个水平的加标回收实验,方法的平均回收率(n=6)为68.1%~111.3%,相对标准偏差为1.2%~12.3%。利用该方法对市售的20批次鸡蛋样品进行测定,均未检出目标物。本方法简单、灵敏、准确,可实现鸡蛋中10种氨基糖苷类药物残留的批量检测。     

丽春红G与妥布霉素的共振散射光谱研究及其分析应用

在弱酸性条件下,丽春红G和妥布霉素反应后形成的产物导致体系的共振散射强度急剧增强,并在276、382和597 nm波长处产生3个新的共振散射峰,最大散射波长为597 nm.研究了反应的适宜条件和体系的光谱特征,妥布霉素的浓度在0.05~6.88μg/mL范围内与共振散射强度(ΔIRS)呈良好的线性关系,线性回归方程为△I597 nm=1.52c-2.68(R=0.9986),方法的检出限(3σ)为22.9 ng/mL.方法已用于硫酸妥布霉素注射液和滴眼液中含量的测定,结果满意.     

基于HILIC模式的超高效液相色谱-串联质谱法检测牛奶中12种氨基糖苷类药物

利用低密度键合C18柱,在亲水作用色谱(HILIC)模式下,对氨基糖苷类(AGs)抗生素进行分离测定,建立了牛奶中12种AGs类药物的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。方法采用乙腈、甲酸和水作为流动相,梯度洗脱,40℃柱温条件,整个反应体系中未使用离子对试剂。该方法在250~5000μg/L范围内对庆大霉素和新霉素、150~3000μg/L范围内对安普霉素和巴龙霉素以及在50~1000μg/L范围内对其它6种药物的线性关系良好。方法的检测限为20~100μg/L,定量限为50~250μg/L。20~1000μg/L浓度添加试验表明,样品中的平均添加回收率在60.9%~109.2%之间,日内变异系数在6.8%~15%之间,日间变异系数在3.2%~18%之间。综上所述,本研究建立的AGs类抗生素残留检测方法能够为AGs类抗生素的残留监测提供有效的技术支持。     

曲利本红分光光度法测定氨基糖苷类抗生素

在pH2.8~7.0的条件下,曲利本红(TR)与硫酸妥布霉素(TOB)、硫酸庆大霉素(GEN)和硫酸新霉素(NEO)等氨基糖苷类抗生素反应生成红色离子缔合物,最大显色波长位于392nm(NEO、GEN)和570nm(TOB),不同体系的线性范围从0~14.0mg.L-1至0~16.0mg.L-1,摩尔吸光系数(ε)在7.65×103~1.40×104L.mol-1.cm-1之间;最大褪色波长位于502nm(NEO)和498nm(GEN、TOB),线性范围从0~13.0mg.L-1至0~16.0mg.L-1,摩尔吸光系数(ε)在4.02×103~9.32×103L.mol-1.cm-1之间。当用双波长叠加法测定时,ε值在1.46×104~2.67×104L.mol-1.cm-1之间。探讨了适宜的反应条件及主要的分析化学性质。该法用于市售药物中氨基糖苷类抗生素含量的测定,结果满意。     

离子色谱-脉冲安培电化学检测引流组织液中的妥布霉素

建立了一种离子色谱(IC)分离,脉冲安培电化学法(PAD)直接检测人体引流组织液中妥布霉素的分析方法.采用高交换容量阴离子交换柱和低浓度KOH在线淋洗分离,不需要采用衍生化和离子对-柱后加碱等实现分离,并可在短时间内完成妥布霉素的测定.采用本方法测定的妥布霉素线性范围为0.05～10 mg/L,线性相关系数为0.9997,保留时间、峰面积和峰高的相对标准偏差分别为0.14％,0.38％和0.81％,检出限为7.11 μg/L.本方法成功应用于骨髓炎患者引流组织液中妥布霉素的测定,样品实际加标回收率为100.8％.     

Copolymers of tetrafluoroethene with chlorotrifluoroethene and with bromotrifluoroethene

Tetrafluoroethene (TFE)–chlorotrifluoroethene (CTFE) and TFE–bromotrifluoroethene (BTFE) copolymers have been synthesized by solution copolymerization over the entire range of comonomer composition. Crystallinity data are reported and first- and second-order transitions have been investigated by DSC. Glass transition temperatures of TFE-CTFE copolymers vary in a nonlinear fashion in the range defined by the homopolymers conforming best to the Johnston equation; the behavior in the TFE-BTFE system is more linear. Whereas TFE-BTFE copolymers show a steep decrease of melting temperature at higher BTFE content, due to the amorphous character of the polymers, more regular behavior was found for TFE-CTFE copolymers. Enthalpies of fusion are also reported. The results are discussed in relation to copolymer composition and structure and are compared with data on tetrafluoroethene–hexafluoropropene (FEP) fluorocarbon resins.     

Asymmetric sorbents with N-carboxymethyl-L-valine and with N-carboxymethyl-L-aspartic acid

Conclusions The asymmetric sorbents with N-carboxymethyl-L-valine with N-carboxymethyl-L-aspartic acid can be used to resolve racemates by the ligand-exchange chromatography method. Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2378–2380, October, 1976.     

Extraction with supercritical gases in coupling with thin-layer chromatography

Summary Numerous substances can be extracted from samples by supercritical gases, e.g. either carbon dioxide or nitrous oxide in the fluid condition at temperatures of 40° C and pressures between 70 and 400 bar. An apparatus for such solvent-free extraction in the analytical field is described. It is coupled directly with a receiving apparatus for subsequent thin-layer chromatography. Three examples with corresponding chromatograms show the possibilities and advantages of this new coupling procedure.

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Extraktion mit überkritischen Gasen in Kopplung mit der Dünnschicht-Chromatographie1. Mitteilung: Aufbau der Apparatur, Handhabung und Anwendung

Zusammenfassung Zahlreiche Substanzen lassen sich mit überkritischen Gasen aus Proben fraktioniert abtrennen. Als Gase dienen z.B. Kohlendioxid und Distickstoffoxid im fluiden Zustand, d.h. bei Temperaturen von 40° C und Drücken zwischen 70 und 400 bar. Für derartige lösungsmittelfreie Extraktionen im analytischen Bereich wird eine Apparatur beschrieben. Sie ist direkt mit einer Auffangapparatur zur anschließenden Dünnschicht-Chromatographie gekoppelt. An 3 Beispielen mit entsprechenden Chromatogrammen werden die Möglichkeiten und Vorteile dieser neuen Kopplungsmethode demonstriert.

     

Reactions of indole derivatives with cardioprotective activity with reactive oxygen species. Comparison with melatonin

We have previously reported on the synthesis of novel indole derivatives containing an amine-triazole moiety (1a-d, 2a-c), and their antioxidant activity on in vitro non-enzymatic rat hepatic microsomal lipid peroxidation. Some of the compounds showed protective activity against oxidative injury of ischemic myocardium. In the present paper we investigated the interactions of these derivatives with reactive oxygen species, in order to find a mechanism of their antioxidant capacity and to identify structural characteristics responsible for these properties. These interactions were compared with melatonin, which is also an indole derivative. The antioxidant profiles of the compounds were established by different in vitro protocols as follows: 1) by the interaction of the compounds with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable free radical, 2) their scavenging effects on superoxide anions using an enzymic system of xanthine-xanthine oxidase, 3) their inhibitory effects on xanthine oxidase and 4) their ability to scavenge hydroxyl radicals by comparison with dimethyl sulfoxide (DMSO) for *OH. All compounds were found to interact with DPPH, most of them to be superoxide anion scavengers and to be strong hydroxyl radical scavengers. Derivatives 1a and 1d substituted on the nitrogen of the indolic nucleus were found to have better antioxidant properties than the reference compounds used and melatonin.     

Voltammetry with a Fluoride-Selective Electrode with Solid-Phase Reference System

Experimental results obtained in a study of the voltammetric response of an all-solid fluoride-selective electrode based on LaF₃ (Eu²⁺ 0.8 mol %), LaF₃ (Sr²⁺ 5 mol %) and CeF₃ (Sr²⁺ 5 mol %) single crystals brought in contact with Ag, Bi, and Sn metal samples are presented. The method of cathodic inversion voltammetry was applied to study the reduction of La³⁺ and Ce³⁺-cations from the rigid sublattice of solid electrolytes, which determines the threshold of the electrochemical stability of a membrane. Anodic inversion voltammetry was used to investigate the characteristics of solid-phase generation of metal fluorides at the interface between the fluoride-selective electrode and metals.     

Microfibrillated cellulose with sizing for reinforcing composites with LDPE

Microfibrillated cellulose (MFC) fibers were acylated by the sizing agent, alkenyl succinic anhydride (ASA) reagent in an aqueous medium, by simple impregnation. The chemical modification was confirmed by Fourier transform infrared spectroscopy and solid-state ¹³C NMR. All the samples were combined with low-density polyethylene and the morphology, thermal properties, mechanical properties and water absorption behavior of the ensuing composites were investigated. The chemical modification of the MFC with ASA improved the interfacial adhesion with the matrix and hence the mechanical properties of the composites while decreasing their water uptake capacity. In addition, it was shown that the degree of substitution strongly influenced the performance of the composites.     

Reaction of isatin with alkylating agents with acidic methylenes

The reaction of isatin (1) with different alkyl halides 2 and alkaline carbonates in aprotic polar solvents leads mainly to N-alkyl derivatives 3. The use of alkylating agents that have acidic methylenes leads to competitive formation of the corresponding epoxide 5. The formation of 5 is favored by low-polarity solvents at low temperatures and strong bases. Epoxides 5c, d obtained using NaEtOH/EtOH at 0–5 °C are transformed into the corresponding 4-quinolinones 6 at higher temperatures. The use of Ag₂CO₃ allows obtaining compounds 3 as major products, along with varying amounts of labile O-alkyl derivatives 4 and dimerization products.     

Multielement analysis with ICP-AES-possibilities for quality control with CRMs

Summary An analysis using Certified Reference Materials (CRMs) together with routine samples is by far the best approach for quality control in multielement analysis of environmental samples. The selection of the correct CRM is thus the first important step for all reliable analysis. The chosen material should have a similar matrix, similar concentration of the element(s) of interest and a sufficient number of well-certified elements. For the analysis of samples from the Environmental Specimen Bank only a few CRMs could be successfully used. These were analyzed for a considerable period of time, together with the routine samples for quality control. The results of these analyses were compared with the certified values.