固相萃取–超高效液相色谱三重四级杆质谱联用法测定水中四环素、土霉素及罗红霉素

建立了固相萃取–超高效液相色谱三重四级杆质谱联用法同时测定水中的罗红霉素、四环素和土霉素残留。水样经过固相萃取纯化、富集,液质联用分析,采用甲酸溶液和乙腈作为流动相,在5 min内完成对3种目标化合物的分析,3种目标化合物的方法检出限介于0.08~0.35 ng/L之间,测定结果的相对标准偏差为1.4%~5.6%,空白样品和实际样品的加标回收率分别为82.5%~114%,71.5%~126%。     

生物质碳点的合成及初步用于盐酸土霉素的测定(英文)

以活性炭为碳源,过氧化氢和醋酸为混合氧化剂,通过化学氧化法合成了碳点。经过乙醚提取纯化,并用聚乙二醇2000进一步钝化,碳点性能得到了改善。最终制得的碳点在316 nm处激发时,最大发射波长出现在435 nm左右,其荧光量子产率为19.6%。盐酸土霉素对碳点有猝灭作用,据此实现了对土霉素的测定。该方法线性关系良好(r=0.998 6),回收率在98.0%~102.0%(RSD=1.7%),检测限达1.4×10-3μg·mL-1。     

高效液相色谱同时测定饲料中三种抗生素

建立了反相高效液相色谱法同时检测饲料中土霉素、四环素、金霉素的方法.色谱柱为AichromBond-AQ C18柱,150×4.6mm,粒度5μm;流动相:0.01mol/L磷酸二氢钠溶液(pH2.5)+乙氰,采用梯度洗脱,乙氰浓度在0～13min内由13%上升到40%;柱温35℃;流速为1.0mL/min;进样量101μL;检测波长375nm.方法检出限:土霉素和四环素0.25μg/mL、金霉素0.50μg/mL,回收率91.70%～101.19%,RSD<1.39%(n=7).     

An overview of analytical methodologies for the determination of antibiotics in environmental waters

The widespread occurrence of antibiotics as contaminants in the aquatic environment has increased attention in the last years. The concern over the release of antibiotics into the environment is related primarily to the potential for the development of antimicrobial resistance among microorganisms. This article presents an overview of analytical methodologies for the determination of quinolone (Qs) and fluoroquinolone (FQs), macrolide (MLs), tetracycline (TCs), sulfonamide (SAs) antibiotics and trimethoprim (TMP) in different environmental waters. The analysis of these antibiotics has usually been carried out by high-performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) and to a lesser extent by ultraviolet (UV) or fluorescence detection (FD). A very important step before LC analysis is sample preparation and extraction leading to elimination of interferences and prevention of matrix effect and preconcentration of target analytes.     

气泡富集-高效液相色谱法测定地表水样中微量土霉素

建立了气泡富集-高效液相色谱（HPLC）测定地表水样中微量土霉素的方法。采用新型样品前处理方法--气泡富集法,对水溶液中的微量土霉素进行富集,考察了气泡富集条件对富集效果的影响。研究发现,在优化的气泡富集和色谱条件下,土霉素的富集倍数可达37.06,土霉素含量测定的RSD为4.8%（n=11）,LOD为0.038 mg/L。将该方法用于地表水样中土霉素的测定,平均加标回收率为101.9%。可见,气泡富集法对土霉素的富集效果好,能与色谱结合用于地表水样中土霉素的快速、灵敏、准确检测。同时,在进行样品前处理时无需任何有机溶剂,而且装置简单、成本低廉、易操作。可见气泡富集法是一种非常有研究和推广价值的绿色样品前处理方法,有望用于复杂样品中其他微量甚至痕量物质的分析。     

钙对钐、铕-四环素类体系荧光法测定钐和铕的增敏作用及其机理探讨

本文研究了常见金属离子（Cr3+、Mn2+、Fe3+、Ni2+、Cu2+、Ca2+、Sr2+、Ba2+、Sn2+、Al3+、Zn2+、Li+、Ms2+）对钐、铕-四环素（TC）、土霉素（OTC）、强力霉素（DOTC）、金霉素（CTC）体系荧光的影响，并从电子自旋磁性和多核络合物的形成等方面对其作用机理进行了探讨。进一步探讨了Ca2增敏TC类体系恻定Sm3+、Eu3+的最佳测定条件。由于钙的加入，可使钐、铕的荧光强度分别增敏3～5和6～30倍。以TC体系为最佳，加入钙，可分别使钐、铕的检测限由38.2和0.09μg／L降低到7.9和0.015μg／L。成功地对样品进行了分析测定。     

毛细管电泳电化学发光法测定蜂蜜中土霉素残留量

基于土霉素对联吡啶钌(Ru(bpy)2+3)的电化学发光(ECL)信号的增强效应,建立了毛细管电泳-电化学发光法(CE-ECL)测定土霉素的新方法。利用场放大效应将检测灵敏度提高了3.5倍,最佳检测电位为1.22 V,运行缓冲液为8 mmol·L-1硼砂溶液(p H 8.0),进样时间及电压分别为6 s和10 k V。在优化条件下,土霉素可在9 min内检出,其线性范围为20~200μg·L-1,相关系数为0.995 3,仪器检出限(S/N=3)为5μg·L-1;5次测定100μg·L-1土霉素溶液的ECL信号和迁移时间的日内重现性分别为2.4%和2.1%,日间重现性分别为3.6%和2.8%。方法用于市售蜂蜜中土霉素残留的测定,在200,1 000,2 000μg·kg-1加标浓度下的回收率为91.5%~105.2%。方法检出限(LOD,S/N=3)为10μg·kg-1,低于食品中土霉素的最大残留限值(MRL)。结果表明该方法在食品分析中具有一定的应用价值。     

生物质碳点的合成及初步用于盐酸土霉素的测定

以活性炭为碳源,过氧化氢和醋酸为混合氧化剂,通过化学氧化法合成了碳点。经过乙醚提取纯化,并用聚乙二醇2000进一步钝化,碳点性能得到了改善。最终制得的碳点在316nm处激发时,最大发射波长出现在435nm左右,其荧光量子产率为19.6%。盐酸土霉素对碳点有猝灭作用,据此实现了对土霉素的测定。该方法线性关系良好(r=0.9986),回收率在98.0%~102.0%(RSD=1.7%),检测限达1.4×10^-3μg·mL^-1。     

Highly luminescent water-dispersed silicon quantum dots for fluorometric determination of oxytetracycline in milk samples

A fluorescent probe based on silicon quantum dots (SiQDs) was developed for the selective and sensitive detection of oxytetracycline (OTC) via the inner filter effect (IFE). The water-soluble fluorescent SiQD was synthesized based on the reaction of 3-Aminopropyltriethoxysilane (APTES) and sodium citrate as precursors by the one-pot hydrothermal process. The strong fluorescence emission of quantum dots (QDs) was obtained at 440 nm when excited at 350 nm and OTC had a broad absorption band between 200 and 400 nm. The excitation spectrum of SiQDs was completely overlapped with the absorption spectrum of OTC. The light at an excitation wavelength of QDs absorbed by OTC caused a decrease in fluorescence intensity with an increase in the concentration of OTC. Under optimal conditions, the linear concentration range was 0.92–9.2 µg mL1 with a detection limit (LOD; S/N = 3) of 0.19 µg mL ^-1 . The proposed method was applied to the determination of OTC in milk samples and satisfactory recoveries (98.8–100.5%) with low RSD % values (0.93–2.31%) were achieved. This simple, selective, sensitive, rapid, and cheap method can be used as a promising tool for OTC analysis in food safety.