肌肉组织中四环素类抗生素的固相萃取-液相色谱法测定

建立了四环素类抗生素的高灵敏度测定方法，通过对实验条件的优化，采用固相萃取-反相高效液相色谱法同时测定肌肉组织中的土霉素(oxytetracycline)、四环素(tetracycline)、金霉素(chlortetracycline)3种四环素类抗生素残留量；土霉素、四环素、金霉素的检出限分别为20、40、100μg／kg；方法相对标准偏差为5．1％-7．1％(n＝5)，平均回收率为80％—82％。     

高效液相色谱法测定水产品中四环素类抗生素残留

建立了一种高效液相色谱法测定水产品中土霉素、四环素、去甲基金霉素、金霉素、脱氧土霉素的分析方法。样品用5.0%高氯酸溶液提取,上清液用OasisHLB固相萃取柱净化,用紫外检测器于355nm测定。土霉素、四环素、去甲基金霉素检测限为0.01mg/kg,金霉素、脱氧土霉素检出限为0.02mg/kg。5种药物的回收率在74.8%~89.3%之间,相对标准偏差为3.95%~9.95%。方法适用于水产品中四环素类抗生素残留的检测。     

固相萃取-亲水作用色谱法测定废水中四环素类抗生素

建立了固相萃取(SPE)-亲水作用色谱法(HILIC)测定废水中金霉素(CTC)、强力霉素(DC)、四环素(TC)和土霉素(OTC) 4种四环素类抗生素(TCs)残留的新方法.水样经Oasis HLB固相萃取柱净化富集后, 采用以氨基色谱柱及高极性有机溶剂-水相缓冲溶液为流动相的亲水作用色谱法(HILIC)进行分析. 对流动相中缓冲溶液的类型和pH值、离子强度、 有机溶剂的浓度以及流速进行了优化, 确定了以V(乙腈)∶V(6.7 mmol/L柠檬酸铵缓冲溶液, pH 4.0)=85∶ 15混合液为流动相的最佳条件.本方法具有良好的线性关系(r> 0.999)和重现性(峰面积RSD<1.0%), 最低检出限(S/N=3)为12～30 μg/L, 4种四环素类药物添加水平在0.5～10 μg/L范围内的标准加入回收率为 90.6%～106.5%; 相对标准偏差为 2.5%～6.2%.本方法简便、准确、流动相离子强度低,适合于与质谱联用,用于屠宰场污水及医院污水等实际样品检测,结果满意.     

猪肉中四环素类抗生素残留的固相萃取-高效液相色谱荧光测定法

采用固相萃取技术富集、分离猪肉中四环素、土霉素、金霉素、强力霉素4种四环素类抗生素,采用反相高效液相色谱荧光法测定.对固相萃取柱、流动相、检测器等条件进行了优化选择,4种物质的检出限为0.03～ 0.05μg/mL在0.02～0.20 mg/kg添加水平,4种抗生素的加标回收率为60%～91%之间,相对标准偏差(RSD,n=5)为2.1%～5.1%.     

动物源性食品中3类抗生素类药物残留检测

建立了利用固相萃取方法和高效液相色谱法检测猪肌肉中土霉素、甲砜霉素、磺胺甲氧哒嗪的残留的方法.固相萃取技术能快速有效的提取动物源性食品中的抗生素残留.建立的高效液相色谱法在5 ～ 1000 μg/L范围内线性良好(R＞0.999),土霉素、甲砜霉素、磺胺甲氧哒嗪的平均回收率分别为78.6％ ～ 86.2％,77.8％ ...     

固相萃取-色谱测定水、沉积物及土壤中氯霉素和3种四环素类抗生素

建立了固相萃取-高效液相色谱(UV)检测水、沉积物和土壤中的氯霉素、土霉素、四环素和金霉素4种抗生素的方法。水样、土壤和沉积物样品的前处理采用EDTA-McIlvaine缓冲溶液提取,用SAX-HLB串联小柱纯化和富集,用丙酮(含10%甲醇)洗脱进一步减小天然有机质的影响。采用乙腈和0.01mol/L草酸溶液作为流动相,8min内分离4种抗生素。测定了贵阳市阿哈湖、南明河和乌江渡水库的水样及沉积物,均有抗生素检出。     

RP-HPLC法测定水体表层沉积物中的磺胺类与四环素类抗生素

建立了超声提取-固相萃取/反相高效液相色谱检测水体表层沉积物中磺胺类和四环素类抗生素含量的方法。沉积物样品经冷冻干燥后用甲醇-EDTA/Mc Ilvaine缓冲液(1∶1)超声萃取,于40℃下氮气吹除提取液中有机溶剂后,过Poly-Sery HLB固相萃取小柱净化萃取,以ODS-P C_(18)反相色谱柱、紫外检测器进行色谱分析。结果表明:7种磺胺类抗生素在0.025~0.5 mg/L浓度范围内线性关系良好,相关系数(r2)均大于0.999,3个加标水平下的回收率为71.4%~107.6%,相对标准偏差(RSD,n=3)为1.4%~5.2%,方法检出限(MDL)为0.07~0.29 ng/g;3种四环素类抗生素在0.05~1 mg/L浓度范围内线性关系良好,r~2均大于0.999,3个加标水平下的回收率为62.2%~87.9%,RSD(n=3)为1.1%~4.6%,MDL为0.45~0.58ng/g。应用此方法对某城市湖泊及其引水河道表层沉积物进行检测,10种目标抗生素均被检出。该方法简单快速、精确可靠,适用于水体沉积物中磺胺类和四环素类抗生素的检测。     

固相萃取–毛细管气相色谱法同时测定水体中8种有机磷类农药残留

建立固相萃取–毛细管气相色谱法同时测定水体中敌敌畏、乙酰甲胺磷、治螟磷、乐果、甲基对硫磷、马拉硫磷、杀螟硫磷和水胺硫磷8种有机磷类农药残留。样品经OASIS HLB固相萃取柱富集,丙酮洗脱,用毛细管气相色谱(FPD)法进行定量分析。8种有机磷类农残留的质量浓度在0.05~4.0μg/m L范围内与色谱峰面积线性关系良好,相关系数均大于0.998,方法检出限为0.004~0.01μg/m L。测定结果的相对偏差为2.6%~4.5%(n=6),加标回收率为81.6%~106.2%。该方法操作简单、灵敏度高,可用于检测水体中的8种有机磷类农药残留。     

环境样品中双酚类化合物的固相萃取研究进展

双酚类化合物作为一类内分泌干扰物广泛存在于环境介质中,经过多种途径迁移至人体后,可对人体产生内分泌毒性、细胞毒性、基因毒性、生殖毒性、二噁英毒性和神经毒性,已被加拿大政府风险评估识别为进一步优先控制名录。随着环境领域对双酚类化合物的广泛关注,相关研究工作逐渐向水、沉积物、灰尘和生物样品等多介质开拓。但是,由于不同环境样品在基质复杂性和污染物浓度水平等方面存在显著差异,开发提取效率高、净化选择性好、普适性强、操作简单、高通量的提取和净化方法,有助于实现环境介质中双酚类化合物的高灵敏、批量检测。近年来,新型前处理技术发展迅速,尤其是固相萃取技术,在双酚类化合物提取与净化方面取得了长足的发展,不仅在一定程度上克服了传统提取净化方法存在的耗时、耗力和耗溶剂等不足,而且为新型污染物分析提供了更多的技术支持。该文简述了典型双酚类化合物的理化性质、用途用量和环境危害,重点围绕新型固相萃取吸附剂开发和固相萃取模式转变两个方面,总结了固相萃取在双酚类化合物提取净化方法方面取得的进展。商品化固相萃取产品普适性强,在环境监测领域应用范围较广,适用于双酚类化合物的产品种类有限;新型吸附剂研发聚焦吸附容量(如介孔硅材料、碳纳米材料、金属-有机框架材料、环糊精)和选择性(如分子印迹聚合物和混合模式离子交换聚合物)两个方面,种类多样化可满足不同检测需求;越来越多的高灵敏分析仪器不断推向市场,为适应新的发展形势,固相萃取模式正逐渐向微型化、自动化、简易化等方向发展,如QuEChERS、固相微萃取、磁固相萃取等。     

金属有机骨架复合材料在样品预处理中的研究进展

金属有机骨架（MOFs）材料是近几年涌现出的一类新型多功能多孔材料,以金属离子或金属簇为配位中心,与含氧或氮的有机配体通过配位作用形成多孔骨架结构。相比于其他传统无机多孔材料,MOFs具有比表面积高、孔隙率大、热稳定性好和结构与功能多样化的特点,因而被广泛用于气体存储、催化、吸附和分离等领域。MOFs复合材料在样品预处理方面的应用引起了研究者们的极大兴趣和广泛关注。由于MOFs材料和不同功能材料如高分子聚合物、碳基材料以及磁性材料组装复合,使MOFs复合材料的性能优于原来的MOFs材料。综述了近年MOFs复合材料在样品预处理的研究应用,尤其是在固相微萃取、固相萃取以及磁性固相萃取等方面的应用。     

Microwave-assisted micro-solid-phase extraction for analysis of tetracycline antibiotics in environmental samples

In this study, a novel solid-liquid-solid extraction approach, which was termed ‘microwave-assisted micro-solid-phase extraction’ (MAE-μ-SPE), was developed. Target analytes were extracted from the sample into extraction solvent enhanced by microwave field, following adsorption by the adsorbent in the micro-solid-phase extraction device. Without any clean-up steps, the extracts were analysed by high performance liquid chromatography coupled with ultra-violet detector. The MAE-μ-SPE approach was developed for the extraction of four tetracycline antibiotics residues in environmental soil, sludge and atmospheric particulate matters. Variables affecting extraction procedures were systematically investigated. Low detection limits of 0.1–6.3 ng/g and low quantification limits of 0.33–20.7 ng/g were achieved under optimised conditions. The recoveries of antibiotics ranged from 70.6% to 110.5% with relative standard deviation of less than 15.1%. The predominance was showed when compared to conventional MAE and μ-SPE method. According to the results, MAE-μ-SPE was proved to be a simple and effective sample preparation method for the analysis of trace organic contaminants in environmental samples.     

磁性固相萃取-高效液相色谱-串联质谱法测定环境水样中的四环素类抗生素

建立了磁性固相萃取-高效液相色谱-串联质谱同时测定环境水样中四环素类抗生素的方法。以6种四环素类抗生素(差向四环素、土霉素、四环素、去甲金霉素、金霉素和脱水四环素)为目标化合物,考察并优化了吸附和解吸条件,确定了最佳萃取条件。萃取后的目标化合物经ZORBAX Eclipse Plus C₁₈柱分离,用高效液相色谱-串联质谱在多反应监测(MRM)模式下进行检测。在优化的条件下,6种四环素在1~100 μg/L范围内线性关系良好,线性相关系数为0.9967~0.9993,检出限为2.44~25.21 ng/L,样品加标回收率为80.6%~90.0%,日内相对标准偏差(RSDs)为0.6%~2.5%,日间RSDs为1.1%~7.1%。该方法灵敏度高、背景干扰低,适用于环境水样中6种痕量四环素类抗生素的同时检测。     

固相萃取-超高压液相色谱-串联质谱同时分析环境水样中四环素类和喹诺酮类抗生素

应用固相萃取及超高压液相色谱-质谱联用技术,建立了环境水样中4种四环素类和6种喹诺酮类抗生素的同时分析方法。样品经HLB固相萃取柱富集、净化后用甲醇洗脱,以超高压液相色谱-串联质谱仪多反应监测(MRM)离子模式定性、定量分析。以河水和海水为基质,卡巴氧为替代物进行回收率评价,4种四环素类抗生素在加标质量浓度分别为20.0 ng/L和100.0 ng/L时的回收率为94.0%～117.0%,相对标准偏差为2.0%～9.7%(n=4),方法的检出限均为20.0 ng/L;6种喹诺酮类抗生素在加标质量浓度分别为5.0 ng/L和20.0 ng/L时的回收率为63.6%～93.9%,相对标准偏差为1.6%～8.1%(n=4),方法的检出限为0.4 ng/L。结果表明,所建立的方法可成功地应用于近岸海域表层环境水样中目标抗生素残留的分析。     

High‐throughput 96‐well solid‐phase extraction for preparation of tetracycline followed by liquid chromatography and mass spectrometry analysis

Tetracyclines abuse has frequently occurred in aquaculture against bacteria, rickettsiae, spirochetes, and mycoplasmas. In this study, a high‐throughput sample preparation method was developed using 96‐well plate solid‐phase extraction (p‐SPE) and the extract was analyzed by ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS). The experimental conditions were optimized such that the pH is 4, the eluting solvent is methanol (2 mL), and the sorbent is hydrophilic‐lipophilic balance (HLB) microsphere. The whole protocol was validated, and it showed that the tetracyclines were linear with correlation coefficients ≥ 0.9990, precision and accuracy (RSD%) in 3.9–6.1%, and mean recoveries of 88.6–103.6%. To exhibit the potential of 96‐well p‐SPE as a routine tool for inspection and quarantine, fresh aquatic samples were tested, and among which positive samples were observed. This method was demonstrated to be promising for the purification and enrichment of tetracyclines with reduced time and labor, and indeed practically and particularly suitable for widespread tetracyclines analysis.     

Degradation patterns of tetracycline antibiotics in reverse micelles and water

The objective of this study was to determine the chemical stability of tetracycline and oxytetracycline hydro-chlorides in reverse micelles. Their reverse micellar solutions were prepared using cetyltrimethylammonium bromide, water and ethyl formate. The aqueous solutions of the tetracycline antibiotics were also prepared for comparison. The reverse micellar and aqueous solutions were stored at 37 degrees C. Samples were analyzed by high performance liquid chromatography. When evaluation was performed on an aqueous tetracycline HCl solution, its half-life was estimated to be 329 h. Its chemical stability was not improved after being dissolved in the reverse micelles, and a similar half-life of 330 h was observed. However, there were noticeable differences between the two systems in terms of degradation kinetics and degradation byproducts. On the other hand, oxytetracycline HCl was unstable in water so that its half-life was only 34 h. Very interestingly, pronounced improvement in stability was attained with the reverse micellar system: upon dissolving in the reverse micelles, its half-life was increased to 2402 h. There were also marked differences in degradation patterns and mechanisms of oxytetracycline HCl in water and the reverse micelles. Our study indicates that the reverse micellar system has potential applications in solubilizing and stabilizing oxytetracycline HCl, thereby contributing to the development of its dosage forms.     

Trace analysis of tetracycline antibiotics in human urine using UPLC–QToF mass spectrometry

A rapid, sensitive and specific ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC–QToF-MS) method has been developed and validated for simultaneous determination of three tetracyclines (TCs) including oxytetracycline, tetracycline, and chlortetracycline in human urine. Human urine sample preparation involves pH adjustment to 4 with hydrochloric acid, pre-concentration, and cleanup by solid phase extraction (SPE) process. The chromatographic separation of all TCs was achieved in less than 5 min using UPLC and ESI-QToF-MS was successfully employed for the identification and quantification. The accurate masses of the product ions were calculated using lock mass correction, and were deviated from the theoretical masses by 0.5–1.9 mDa and 1.1–4.5 ppm, respectively. The developed method was validated in terms of linearity, sensitivity, selectivity, decision limit, detection capability, accuracy, and precision. Limit of detection and limit of quantitation for all TCs were estimated in the range of 0.089–0.138 ng mL^{− 1} and 0.294–0.455 ng mL^{− 1}, respectively. High overall recoveries of greater than 90% were achieved with linear responses over the 0.5–2 ng mL^{− 1} range for all TCs in urine samples.     

Simple and rugged SPE method for the determination of tetracycline antibiotics in serum by HPLC using a volatile mobile phase

Summary A simple and rugged SPE method for the determination of tetracycline (TC), minocycline (MC) and demeclocycline (DCC) in porcine serum by high performance liquid chromatography (HPLC) was developed. The spiked serum sample was pretreated with 2% phosphoric acid followed by a simple and rugged solid-phase extraction procedure using the Oasis^TM HLB extraction cartridges. High and reproducible recoveries were obtained even though the cartridges were run dry. The extracted sample analytes were injected onto a Waters SymmetryShield^TM RP₈ column. The mobile phase was a simple volatile solution containing 0.1% TFA, 2% methanol and 7% acetonitrile in Water. The antibiotics were detected at 350 nm. The calibration curves were linear from 2.0 to 25.0 μg mL⁻¹ of TC and MC with DCC as the internal standard at a concentration of 25.0 μg mL⁻¹. For six replicate analyses, the average recoveries of TC and MC from porcine serum sample fortified at the level of 2.5 μg mL⁻¹ were 96.1% with 1.3% RSD and 101% with 0.54% RSD; at level of 0.5 μg mL⁻¹ the average recoveries were 88% with 1.6% RSD and 97.8% with 1.4% RSD.     

Simultaneous extraction and determination of fluoroquinolones,tetracyclines and sulfonamides antibiotics in soils using optimised solid phase extraction chromatography-tandem mass spectrometry

An analytical method was developed for the simultaneous extraction and determination of 18 fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) antibiotics from soils using solid phase extraction and liquid chromatography-tandem mass spectrometry. The soils were extracted by different solvents with the help of mechanical shaking and ultrasonic treatment at 59?kHz, followed by a strong anion exchange (SAX) cartridge to clean up soil samples and a hydrophilic lipophilic balance (HLB) cartridge as enrichment. The method was evaluated by testing the following variables: extraction solvents, the type of SPE cartridges, solvent volumes, initial spiking levels and soil types (silty clay loam and clay loam soils). The soil extraction method was validated using these two types of soils, representing two typical agricultural soils in northern China. For 2?g soil, the extraction steps with the mixture of potassium phosphate buffer and acetonitrile (ACN) (1/1, v/v, pH 3.2) provided satisfactory recoveries. In the clay loam soil, the recoveries of all the compounds were from 56% to 89% at the spiking level of 50?µg?kg^?1 soil, and from 69% to 97% at the spiking level of 200?µg?kg^?1 soil, respectively. Recoveries in silty clay loam soil were similar to that in clay loam. The method was successfully employed using soil samples collected from a farmland and afforestion area irrigated with sewage in northern China. The result indicates that trace antibiotics in sewage may accumulate in soil irrigated by river water containing sewage.     

On-line solid phase extraction LC-MS/MS analysis of pharmaceutical indicators in water: A green alternative to conventional methods

A method using automated on-line solid phase extraction (SPE) directly coupled to liquid chromatography/tandem mass spectrometry (LC-MS/MS) has been developed for the analysis of six pharmaceuticals by isotope dilution. These selected pharmaceuticals were chosen as representative indicator compounds and were used to evaluate the performance of the on-line SPE method in four distinct water matrices. Method reporting limits (MRLs) ranged from 10 to 25 ng/L, based on a 1 mL extraction volume. Matrix spike recoveries ranged from 88 to 118% for all matrices investigated, including finished drinking water, surface water, wastewater effluent and septic tank influent. Precision tests were performed at 50 and 1000 ng/L with relative standard deviations (RSDs) between 1.3 and 5.7%. A variety of samples were also extracted using a traditional off-line automated SPE method for comparison. Results for both extraction methods were in good agreement; however, on-line SPE used approximately 98% less solvent and less time. On-line SPE coupled to LC-MS/MS analysis for selected indicators offers an alternative, more environmentally friendly, method for pharmaceutical analysis in water by saving time and costs while reducing hazardous waste and potential environmental pollution as compared with off-line SPE methods.