Trace determination of beta-lactam antibiotics in surface water and urban wastewater using liquid chromatography combined with electrospray tandem mass spectrometry

A sensitive and reliable method using liquid chromatography-electrospray tandem mass spectrometry has been developed and validated for the trace determination of beta-lactam antibiotics in natural and wastewater matrices. Water samples were enriched by solid-phase extraction. The analytes included amoxicillin (AMOX), ampicillin (AMP), oxacillin (OXA), cloxacillin (CLOX) and cephapirin (CEP). Average recoveries of beta-lactams (BLs) in fortified samples were generally above 75% (except amoxicillin) with the standard deviations lower than 10% in water matrices. Amoxicillin was not quantified due to poor recovery (less than 40%) in the investigated water matrices. Matrix effects were found to be minimal when measuring these compounds in water matrices. The accuracy, within- and between-run precision of the assay fell within acceptable ranges of 15% absolute. The method detection limit (MDL) was estimated to range between 8 and 10 ng/L in surface water, 13 and 18 ng/L in the influent and 8 and 15 ng/L in the effluent from a wastewater treatment plant. A large number of actual water samples were analyzed using this method in order to evaluate the occurrence of the beta-lactams in a river and a wastewater treatment plant in northern Colorado. Most of the samples were negative for all analytes. These compounds were found at 15-17 ng/L in the three influent samples and at 9-11 ng/L in three surface water samples out of a total of 200 samples. This indicates that contamination by beta-lactam antibiotics is of minor importance to the small mixed-watershed.     

Trace determination of 10 β-lactam antibiotics in environmental and food samples by capillary liquid chromatography

A sensitive and reliable method using capillary HPLC with UV-diode array detection (DAD) has been developed and validated for the trace determination of residues of 10 β-lactam antibiotics of human and veterinary use, in milk, chicken meat and environmental water samples. The analytes included ampicillin, amoxicillin, penicillin V, penicillin G, cloxacillin, oxacillin, dicloxacillin, nafcillin, piperacillin and clavulanic acid. Legal levels are regulated by the EU Council regulation 2377/90 in animal edible tissues for these compounds. For food analysis, a solid-phase extraction (SPE) procedure consisting in a tandem of Oasis HLB and Alumina N cartridges was applied for off-line preconcentration and cleanup. For water analysis, the first step was only necessary. The limits of detection for the studied compounds were between 0.04–0.06 μg l⁻¹ for water samples and 0.80–1.40 μg l⁻¹ (or μg kg⁻¹) in the case of foods derived from animals. Average recoveries for fortified samples at different concentration levels ranged between 82.9% and 98.2%, with relative standard deviations (RSDs) lower than 9%. The method showed the advantages of capillary HPLC for the detection of these widely applied antibiotics in different samples at very low concentration levels.     

Application of a dispersive solid‐phase extraction method using an amino‐based silica‐coated nanomagnetic sorbent for the trace quantification of chlorophenoxyacetic acids in water samples

Herein, an amino‐based silica‐coated nanomagnetic sorbent was applied for the effective extraction of two chlorophenoxyacetic acids (2‐methyl‐4‐chlorophenoxyacetic acid and 2,4‐dichlorophenoxyacetic acid) from various water samples. The sorbent was successfully synthesized and subsequently characterized by scanning electron microscopy, X‐ray diffraction, and Fourier‐transform infrared spectroscopy. The analytes were extracted by the sorbent mainly through ionic interactions. Once the extraction of analytes was completed, they were desorbed from the sorbent and detected by high‐performance liquid chromatography with ultraviolet detection. A number of factors affecting the extraction and desorption of the analytes were investigated in detail and the optimum conditions were established. Under the optimum conditions, the calibration curves were linear over the concentration range of 1–250, and based on a signal‐to‐noise ratio of 3, the method detection limits were determined to be 0.5 μg/L for both analytes. Additionally, a preconcentration factor of 314 was achieved for the analytes. The average relative recoveries obtained from the fortified water samples varied in the range of 91–108% with relative standard deviations of 2.9–8.3%. Finally, the method was determined to be robust and effective for environmental water analysis.     

Large-volume sample stacking for the analysis of seven beta-lactam antibiotics in milk samples of different origins by CZE

A method for the simultaneous determination of eight beta-lactam antibiotics (nafcillin, cloxacillin, oxacillin, dicloxacillin, ampicillin, amoxicillin, and penicillin G) in fortified milk samples of different origins has been proposed by using CZE with diode-array detection (CZE-DAD). Optimum separation was obtained on a 64.5 cm x 75 microm bubble cell capillary using 175 mM Tris buffer with 20% ethanol at pH 8.0. Methylparaben has been used as an internal standard (IS). Taking into account the lack of sensitivity of the UV-Vis detection, a solvent extraction/SPE method was applied for off-line preconcentration and sample cleanup, and also an on-line preconcentration methodology, such as large-volume sample stacking (LVSS) with polarity switching, was developed, providing LODs ranging from 2 to 10 microg/L. The method permits the quantification of these residues below the levels established in milk by the EU Regulation. Satisfactory recoveries ranging from 86 to 93% were also obtained in milk samples of different origins.     

Ultrapreconcentration and determination of organophosphorus pesticides in water by solid‐phase extraction combined with dispersive liquid–liquid microextraction and high‐performance liquid chromatography

Solid‐phase extraction coupled with dispersive liquid–liquid microextraction was developed as an ultra‐preconcentration method for the determination of four organophosphorus pesticides (isocarbophos, parathion‐methyl, triazophos and fenitrothion) in water samples. The analytes considered in this study were rapidly extracted and concentrated from large volumes of aqueous solutions (100 mL) by solid‐phase extraction coupled with dispersive liquid–liquid microextraction and then analyzed using high performance liquid chromatography. Experimental variables including type and volume of elution solvent, volume and flow rate of sample solution, salt concentration, type and volume of extraction solvent and sample solution pH were investigated for the solid‐phase extraction coupled with dispersive liquid–liquid microextraction with these analytes, and the best results were obtained using methanol as eluent and ethylene chloride as extraction solvent. Under the optimal conditions, an exhaustive extraction for four analytes (recoveries >86.9%) and high enrichment factors were attained. The limits of detection were between 0.021 and 0.15 μg/L. The relative standard deviations for 0.5 μg/L of the pesticides in water were in the range of 1.9–6.8% (n = 5). The proposed strategy offered the advantages of simple operation, high enrichment factor and sensitivity and was successfully applied to the determination of four organophosphorus pesticides in water samples.     

Rapid quantitative determination of ephedra alkaloids in tablet formulations and human urine by microchip electrophoresis

Microchip electrophoresis with fluorescence detection has been applied for fast separation and determination of ephedra alkaloids in pharmaceutical formulations and body fluids. A custom epifluorescence microscope setup was employed and the compounds were separated within 40?s, allowing the detection of less than 200?ng/L for both analytes. Quantitation of the two stimulants was performed via a derivatization step using FITC without any extraction or preconcentration steps. The effects of different microchip types and excitation light sources were investigated and the method was successfully applied for the analysis of these compounds in tablet formulations, yielding recovery rates from 100.2 to 101.1% and relative standard deviations from 1.5 to 3.4%. Analysis of ephedrines was also carried out with human urine samples at detection limits of 500-1000?ng/L and relative standard deviations from 2.2 to 3.3% using argon ion LIF detection.     

Temperature‐controlled liquid–liquid microextraction combined with high‐performance liquid chromatography for the simultaneous determination of diazinon and fenitrothion in water and fruit juice samples

A simple, environmentally benign, and rapid method based on temperature‐controlled liquid–liquid microextraction using a deep eutectic solvent was developed for the simultaneous extraction/preconcentration of diazinon and fenitrothion. The method involved the addition of deep eutectic solvent to the aqueous sample followed by heating the mixture in a 75°C water bath until the solvent was completely dissolved in the aqueous phase. Then, the resultant solution was cooled in an ice bath and a cloudy solution was formed. Afterward, the mixture was centrifuged and the enriched deep eutectic solvent phase was analyzed by high‐performance liquid chromatography with ultraviolet detection for quantification of the analytes. The factors affecting the extraction efficiency were optimized. Under the optimized extraction conditions, the limits of detection for diazinon and fenitrothion were 0.3 and 0.15 μg/L, respectively. The calibration curves for diazinon and fenitrothion exhibited linearity in the concentration range of 1–100 and 0.5–100 μg/L, respectively. The relative standard deviations for five replicate measurements at 10.0 μg/L level of analytes were less than 2.8 and 4.5% for intra‐ and interday assays, respectively. The developed method was successfully applied to the determination of diazinon and fenitrothion in water and fruit juice samples.     

Microwave-assisted extraction combined with dispersive liquid-liquid microextraction as a new approach to determination of chlorophenols in soil and sediments

A new method was applied for extraction of five chlorophenols from soil and marine sediment samples. Microwave-assisted extraction coupled with dispersive liquid-liquid microextraction followed by semi-automated in-syringe back-extraction technique was used as an extraction technique. Microwave-assisted extraction was performed by using 2.0 mL of alkaline water at pH 10.0. After extraction, the pH of extraction solution was adjusted at 6.0 and dispersive liquid-liquid microextraction procedure was done using 1.0 mL of acetone as a disperser solvent and 37.0 μL of chlorobenzene as extraction solvent. About 20.0 ± 0.5 μL sedimented phase was collected after centrifugation step. Then, chlorophenols were back extracted into 20 μL of alkaline water at pH 12.0 within the microsyringe. Finally, 20.0 μL of aqueous solution was injected into high performance liquid chromatography with ultra violet detection for analysis. The obtained recovery and preconcentration factors for the analytes were in the range of 68.0-82.0% and 25-30, respectively, with relative standard deviations ≤7.6%. The limits of the detection were found in the range of 0.0005-0.002 mg/kg. The method provides a simple and fast procedure for the extraction and determination of chlorophenols in soil and marine sediment samples.     

Simultaneous determination of selected endocrine disrupters (pesticides,phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by on-line SPE (PROSPEKT) and analysis by liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry

In this study, a new procedure, based on on-line solid-phase extraction (SPE) and analysis by liquid-chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), has been developed for the simultaneous, multianalyte determination of 21 selected pesticides, phenols and phthalates in water. SPE was carried out on polymeric PLRP-s cartridges by percolating 20 mL-samples. For sample preconcentration, the performance of a prototype programmable field extraction system (PROFEXS) was evaluated against the commercial laboratory bench Prospekt system used for method development. The Profexs is designed for the automated on-site sampling, SPE preconcentration, and storage of up to 16 samples in SPE cartridges. These cartridges are further eluted and on-line analyzed with the Prospekt coupled to the chromatographic system. In the optimized method, where completely on-line SPE-LC-MS analysis of the samples is carried out with the Prospekt in the laboratory, detection limits lower than 100 ng/L, and satisfactory precision (relative standard deviations <25%) and accuracies (recovery percentages >75%) were obtained for most investigated compounds from the analysis of spiked Milli-Q water. The extraction efficiency achieved with the Profexs was comparable to that of the Prospekt for most compounds and somewhat lower for the most apolar analytes, probably due to adsorption on the pump filters. The completely on-line optimized method was applied to the analysis of surface water, ground water and drinking water from a waterworks in Barcelona. Some pesticides and phenols were found in both surface water and groundwater at ng/L or µg/L levels, but not in the final drinking water. Di(2-ethylhexyl)phthalate (DEHP) was present in all samples investigated, including blanks. To the author's knowledge, this is the first work describing the application of a fully automated on-line SPE-LC-MS method for the simultaneous analysis of pesticides, phenols, and phthalates in water, and the second one that examines the possibilities of the prototype Profexs for automated on-site SPE preconcentration of organic pollutants from water samples.     

Fabric phase sorptive extraction/GC‐MS method for rapid determination of broad polarity spectrum multi‐class emerging pollutants in various aqueous samples

A rapid extraction and cleanup method using selective fabric phase sorptive extraction combined with gas chromatography and mass spectrometry has been developed and validated for the determination of broad polarity spectrum emerging pollutants, ethyl paraben, butyl paraben, diethyl phthalate, dibutyl phthalate, lidocaine, prilocaine, triclosan, and bisphenol A in various aqueous samples. Some important parameters of fabric phase sorptive extraction such as extraction time, matrix pH, stirring speed, type and volume of desorption solvent were investigated and optimized. Calibration curves were obtained in the concentration range 0.05–500 ng/mL. Under the optimum conditions, the limits of detection were in the range 0.009 –0.021 ng/mL. This method was validated by analyzing the compounds in spiked aqueous samples at different levels with recoveries of 93 to 99% and relative standard deviations of <6%. The developed method was applied for the determination of the emerging contaminants in tap water, municipal water, ground water, sewage water, and sludge water samples. The results demonstrate that fabric phase sorptive extraction has great potential in the preconcentration of trace analytes in complex matrix.     

Preconcentration and dansylation of aliphatic amines using C18 solid-phase packings. Application to the screening analysis in environmental water samples

Precolumn preconcentration and derivatization on solid sorbents (Bond Elut C18 solid-phase extraction cartridges) of low-molecular-mass aliphatic amines in water samples have been performed using dansyl chloride (Dns-Cl) as derivatization reagent. Conditions for analyte preconcentration and derivatization such as volume sample, reagent concentration, time, pH and temperature reaction were optimised. On the basis of these studies a rapid and sensitive method for screening of aliphatic amines in waters is presented. Up to volumes of 5 ml, samples are drawn through the sorbent, the analytes retained are dansylated at basic pH, at 100 degrees C for 10 min or 85 degrees C for 15 min. The derivatized analytes are desorbed with 0.5 ml of acetonitrile. Twenty microl of the collected extracts are chromatographed in a Hypersyl ODS C18 column using an acetonitrile-imidazole (pH 7) gradient for elution. Seven amines and ammonium were separated within 9 min. The Dns derivatives were monitored at 333 nm with UV detection and at lambda(excitation) = 350 nm and lambda(emission) = 530 nm with fluorescence detection. The different signals are compared. Dynamic ranges from 10 to 250 microg/l and limits of detection at the microgram-per-litre level and relative standard deviations from 2 to 15% were obtained for all the amines. The total analysis time (sample treatment plus chromatography) was less than 25 min. The method was applied to determination and screening analysis of these analytes in real environmental water samples.     

Polypyrrole/silica/magnetite nanoparticles as a sorbent for the extraction of sulfonamides from water samples

A magnetic solid‐phase extraction sorbent of polypyrrole/silica/magnetite nanoparticles was successfully synthesized and applied for the extraction and preconcentration of sulfonamides in water samples. The magnetite nanoparticles provided a simple and fast separation method for the analytes in water samples. The silica coating increased the surface area that helped to increase the polypyrrole layer. The polypyrrole‐coated silica provided a high extraction efficiency due to the π–π and hydrophobic interactions between the polypyrrole and sulfonamides. Several parameters that affected the extraction efficiencies, i.e. the amount of sorbent, pH of the sample, extraction time, extraction temperature, ionic strength, and desorption conditions were investigated. Under the optimal conditions, the method was linear over the range of 0.30–200 μg/L for sulfadiazine and sulfamerazine, and 1.0–200 μg/L for sulfamethazine and sulfamonomethoxine. The limit of detection was 0.30 μg/L for sulfadiazine and sulfamerazine and 1.0 μg/L for sulfamethazine and sulfamonomethoxine. This simple and rapid method was successfully applied to efficiently extract sulfonamides from water samples. It showed a high extraction efficiency for all tested sulfonamides, and the recoveries were in the range of 86.7–99.7% with relative standard deviations of < 6%.     

Ionic liquid-based homogeneous liquid-liquid microextraction for the determination of antibiotics in milk by high-performance liquid chromatography

Ionic liquid-based homogeneous liquid-liquid microextraction (IL-based HLLME) high-performance liquid chromatography was developed and applied to the extraction, separation and determination of some antibiotics in milk. The proteins and lipids were removed by adding salt and adjusting the pH value. The homogeneous extraction was applied to the improvement of recoveries for IL phase and analytes. The experimental parameters of the IL-based HLLME, including salt concentration in sample solution, pH value of sample solution, volume of [C(6)MIM][BF(4)], amount of ion-pairing agent (NH(4)PF(6)), and extraction time, were evaluated. The limits of detection for enoxacin, pefloxacin, norfloxacin, enrofloxacin, sulfamethoxazole and sulfadimethoxine were 15.8, 7.07, 5.13, 4.00, 7.79 and 8.33 μg L(-1), respectively. When the proposed method was applied to the analysis of milk samples the recoveries of the analytes ranged from 92.5 to 118.6% and relative standard deviations were lower than 7.00%.     

Tandem use of solid-phase extraction and dispersive liquid-liquid microextraction for the determination of mononitrotoluenes in aquatic environment

Solid‐phase extraction (SPE) in tandem with dispersive liquid–liquid microextraction (DLLME) has been developed for the determination of mononitrotoluenes (MNTs) in several aquatic samples using gas chromatography‐flame ionization (GC‐FID) detection system. In the hyphenated SPE‐DLLME, initially MNTs were extracted from a large volume of aqueous samples (100 mL) into a 500‐mg octadecyl silane (C₁₈) sorbent. After the elution of analytes from the sorbent with acetonitrile, the obtained solution was put under the DLLME procedure, so that the extra preconcentration factors could be achieved. The parameters influencing the extraction efficiency such as breakthrough volume, type and volume of the elution solvent (disperser solvent) and extracting solvent, as well as the salt addition, were studied and optimized. The calibration curves were linear in the range of 0.5–500 μg/L and the limit of detection for all analytes was found to be 0.2 μg/L. The relative standard deviations (for 0.75 μg/L of MNTs) without internal standard varied from 2.0 to 6.4% (n=5). The relative recoveries of the well, river and sea water samples, spiked at the concentration level of 0.75 μg/L of the analytes, were in the range of 85–118%.     

Determination of fluoroquinolone antibiotics by microchip capillary electrophoresis along with time-resolved sensitized luminescence of their terbium(III) complexes

We report on the time-resolved detection of the three fluoroquinolone (FQs) antibiotics ciprofloxacin (CIP), enrofloxacin (ENR) and flumequine (FLU). On addition of terbium(III) ions, the terbium(III)-FQs chelates are formed in-situ in an on-capillary derivatization reaction of a microfluidic system. The laser-induced terbium(III)-sensitized luminescence of the chelates is measured at excitation/emission wavelengths of 337/545 nm. The analytes can be separated and quantified within less than 4 min. A solid phase extraction step for analyte preconcentration can be included prior to chelation and microchip capillary electrophoresis. The analytical ranges of the calibration graphs for CIP, ENR and FLU are from 10.6 to 60.0, 10.3 to 51.0, and 11.5 to 58.8 ng mL^?1, respectively, and the detection limits are 3.2, 3.1 and 3.6 ng mL^?1, respectively. The precision was established at two concentration levels of each analyte and revealed relative standard deviations in the range from 3.0 to 10.2 %. The method was applied to the analysis of FQ-spiked water samples. Figure

We report on the time-resolved detection of the three fluoroquinolone antibiotics. The analytes can be separated and quantified within less than 4 min. A solid phase extraction step for analyte preconcentration can be included prior to chelation and microchip capillary electrophoresis.     

Carbon nanospheres as solid‐phase microextraction coating for the extraction of polycyclic aromatic hydrocarbons from water and soil samples

A solid‐phase microextraction with carbon nanospheres coated fiber coupled with gas chromatographic detection was established for the determination of eight polycyclic aromatic hydrocarbons (naphthalene, biphenyl, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene, and pyrene) in water and soil samples. The experimental parameters (extraction temperature, extraction time, stirring rate, headspace volume, salt content, and desorption temperature) which affect the extraction efficiency were studied. Under the optimized conditions, good linearity between the peak areas and the concentrations of the analytes was achieved in the concentration range of 0.5‐300 ng/mL for water samples, and in the concentration range of 6.0‐2700 ng/g for soil samples. The detection limits for the analytes were in the range of 0.12‐0.45 ng/mL for water samples, and in the range of 1.53‐2.70 ng/g for soil samples. The method recoveries of the polycyclic aromatic hydrocarbons for spiked water samples were 80.10‐120.1% with relative standard deviations less than 13.9%. The method recoveries of the analytes for spiked soil samples were 80.40‐119.6% with relative standard deviations less than 14.4%. The fiber was reused over 100 times without a significant loss of extraction efficiency.     

Separation and Determination of Diol Pollutants Come from Demulsifier in the Produced Water of Oil Fields

This paper introduced a novel test method for determination of the main demulsifier‐based pollutants in the produced water of oil wells, before draining to seawater. The type, concentration and distribution of diols depend on the demulsifier of interest; however, the main chemical species are the same. The novelty of this work is selective extraction and preconcentration of low chain diols in the produced water of oil fields. In this extraction method, dispersive solvent (1.2 mL, acetonitrile) containing extraction solvent (10.0 μL, carbon tetrachloride) was rapidly injected into the water sample containing analytes, and a cloudy solution was formed. After centrifugation (2 min at 3,000 rpm), these droplets were sedimented in the bottom of the conical test tube. Then 2.0 mL of sedimented phase containing preconcentrated analytes was injected into the gas chromatograph with flame ionization detector. The parameters affecting the extraction efficiency were evaluated and optimized. Factors such as the kind and volume of both extraction and disperser solvents, extraction and centrifugation times, pH and temperature, and salt effect were studied and optimized. The method exhibited enrichment factors and recoveries ranging from 39.0 to 44.4 and 78.9 to 92.2%, respectively, within very short extraction time. The linearity (and limit of detection) of the method ranged 4.0‐100.0 (2.0) ng/mL for 1,2‐ethandiol, 6.0‐80.0 (4.0) ng/mL for 1,3‐propandiol, 2.0‐90.0 (1.0) ng/mL ng/mL for 1,4‐butanediol, 5.0‐120.0 (2.0) ng/mL for 1,5‐pentandiol. The relative standard deviations (RSD) for the concentration of diols, 5.0 ng/mL in water by using the internal standard were in the range of 1.5–4.5% (n = 5) and without the internal standard was in the range of 2.6–9.0% (n = 5). It is concluded that this method is successful for determination of diols in produced water samples.     

Analysis of anticancer drugs in sewage water by selective SPE and UPLC-ESI-MS-MS

A trace analytical procedure was developed to assay the anticancer drugs methotrexate, azathioprine, doxorubicin, doxorubicinol, vincristine, ifosfamide, cyclophosphamide, etoposide, and procarbazine in water samples from sewage treatment plants. After concentration and purification using Oasis HLB solid-phase extraction cartridges and Oasis WAX cartridges, the analytes were separated using ultra-high performance liquid chromatography coupled with the electrospray ionization tandem mass spectrometry operating in the positive ion mode. The method showed good precision and accuracy. Recoveries of all analytes were in the range of 45.3-108.9% with relative standard deviations between 2.4-24.5%. The limits of detection for influent and effluent sewage water were in the range of 0.6-7.0 ng/L and 0.5-3.5 ng/L, respectively. It is expected that this method will be applied to investigate the environmental occurrence of anticancer drugs in sewage water.     

在线固相萃取净化-液相色谱-串联质谱法测定猪肉中10种大环内酯类抗生素

建立了在线固相萃取净化-液相色谱-串联质谱检测猪肉中10种大环内酯类抗生素残留的方法。样品经过乙腈提取,提取液40℃旋蒸至干后,分析物用2 mL磷酸盐缓冲液溶解,溶解液经在线固相萃取柱(HLB柱)富集净化,甲醇洗脱,然后转移至XBridge BEH C18色谱柱上,以10 mmol/L乙酸铵水溶液和乙腈溶液为流动相进行分离,最后用串联四极杆质谱检测。结果表明,10种大环内酯类抗生素在0.1~200μg/L范围内呈现良好的线性关系,相关系数均大于0.990。方法的检出限范围为0.05~0.30μg/kg,定量限范围为0.10~1.00μg/kg;添加水平为0.10~10.0μg/kg时,方法回收率为69.6%~115.2%,相对标准偏差(RSD)10%。该方法可以作为猪肉中大环内酯类抗生素的检测方法。     

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。