Development and validation of a solid‐phase extraction method coupled with LC–MS/MS for the simultaneous determination of 16 antibiotic residues in duck meat

The present study was carried out to determine 16 antibiotics belonging to seven different groups (tetracyclines, sulfonamides, penicillins, fluoroquinolones, macrolides, lincosamides and trimethoprims) in duck meat. A solid‐phase extraction method based on Oasis HLB cartridges coupled with liquid chromatography–electrospray ionization tandem mass spectrometry was developed. Solutions of 0.1 m ethylenediaminetetraacetic acid disodium salt and 2% trifluoroacetic acid were used for the preliminary extraction of the target antibiotics from duck meat and n‐hexane was used for purification prior to solid‐phase extraction. Mobile phases composed of 0.1% trifluoroacetic acid in distilled water (solvent A) and 0.1% trifluoroacetic acid in methanol (solvent B), combined with a reversed‐phase C₁₈ analytical column, provided the optimal separation and signal intensity. The linearity of the method was assessed using six concentrations (5, 10, 20, 30, 40, and 50 μg/kg), and the recoveries, which were calculated at three spiking concentrations (5, 10 and 20 μg/kg), were in the range 69.8–103.3% with relative standard deviations (RSDs) ≤ 6.9% for the 16 tested antibiotics. Matrix effects ranging from ?47.2 to ?13.5% were observed for all the analytes, and the limits of quantitation (LOQ), which ranged from 4.93 to 26.21 μg/kg, were much lower than the maximum residue limits (MRLs) set by various regulatory authorities. Ten samples from a market were tested, and none of the target analytes were detected. Thus, a simple and versatile protocol has been developed to detect and quantify 16 antibiotics in duck meat samples.     

Detection of multiple endocrine-disrupting chemicals in milk: Improved and safe high performance liquid chromatography tandem mass spectrometry method

Herein, an improved method for detecting the endocrine-disrupting chemicals in milk is presented, which is based on high performance liquid chromatography tandem mass spectrometry, coupled with a quick, effective, and safe method. The linearity of the proposed method was in the range of 0.05–100 μg/L, and all correlation coefficients were ≥0.9973. At three concentration levels, the spiked recoveries ranged from 77.7 to 107.5%, relative standard deviations ranged from 0.2 to 14.6%, limits of quantitation ranged from 0.1 to 40 μg/kg, limits of detection ranged from 0.03 to 13.3 μg/kg. The proposed method for the identification and quantitation of 26 endocrine disruptors present in milk is not only easy, fast, and cost-efficient but also provides a reference for the detection of various endocrine disruptors in milk and other dairy products.     

Simultaneous determination of seven multiclass veterinary antibiotics in surface water samples in the Republic of Korea using liquid chromatography with tandem mass spectrometry

A simultaneous determination method using solid‐phase extraction and liquid chromatography with tandem mass spectrometry was developed to detect and quantify the presence of seven multiclass veterinary antibiotics (13 compounds in total) in surface water samples, which included the effluents of livestock wastewater and sewage treatment plants, as well as the reservoir drainage areas from dense animal farms. The pH of all water samples was adjusted to 2 or 6 before solid‐phase extraction using Oasis HLB cartridges. The developed method was fully validated in terms of linearity, method detection limit, method quantitation limit, accuracy, and precision. The linearity of all tested drugs was good, with R² determination coefficients ≥ 0.9931. The method detection limits and method quantitation limits were 0.1–74.3 and 0.5–236.6 ng/L, respectively. Accuracy and precision values were 71–120 and 1–17%, respectively. The determination method was successfully applied for monitoring water samples obtained from the Yeongsan River in 2015. The most frequently detected antibiotics were lincomycin (96%), sulfamethazine (90%), sulfamethoxazole (88%), and sulfathiazole (50%); the maximum concentrations of which were 398.9, 1151.3, 533.1, and 307.4 ng/L, respectively. Overall, the greatest numbers and concentrations of detected antibiotics were found in samples from the effluents of livestock wastewater, sewage treatment plants, and reservoir drainage areas. Diverse veterinary antibiotics were present, and their presence was dependent upon the commercial sales and environmental properties of the analytes, the geographical positions of the sampling points, and the origin of the water.     

Simultaneous determination of sulfonamides, tetracyclines and tiamulin in swine wastewater by solid-phase extraction and liquid chromatography-mass spectrometry

Little is known about the contamination level of antibiotics in swine wastewater in China. The highly complex matrix of swine wastewater, which generally has a chemical oxygen demand (COD) concentration as high as 15,000 mg/L, makes it difficult to detect antibiotics at trace levels. In this work, a highly selective and sensitive analytical method was developed for simultaneous determination of three classes of commonly used veterinary antibiotics including five sulfonamides, three tetracyclines and one macrolide in swine wastewater using solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (LC-MS). The method detection limits (MDL) in the swine wastewater were determined to be between 5 and 91 ng/L, depending on specific antibiotics. Except sulfamethizole, all the other eight antibiotics were detected in the swine wastewaters collected from three concentrated swine feeding plants located in the Beijing (China) area, showing a concentration range of 0.62-32.67 microg/L. These results reveal the representative concentration levels of selected antibiotics in the swine wastewaters of Beijing area.     

Multi-class determination of around 50 pharmaceuticals, including 26 antibiotics, in environmental and wastewater samples by ultra-high performance liquid chromatography-tandem mass spectrometry

A multi-class method for the simultaneous quantification and confirmation of 47 pharmaceuticals in environmental and wastewater samples has been developed. The target list of analytes included analgesic and anti-inflammatories, cholesterol lowering statin drugs and lipid regulators, antidepressants, anti-ulcer agents, psychiatric drugs, ansiolitics, cardiovasculars and a high number (26) of antibiotics from different chemical groups. A common pre-concentration step based on solid-phase extraction with Oasis HLB cartridges was applied, followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) measurement. All compounds were satisfactorily determined in just one single injection, with a chromatographic run time of only 10 min. The process efficiency (combination of the matrix effect and the extraction process recovery) for the 47 selected compounds was evaluated in nine effluent wastewater (EWW) samples, and the use of different isotope-labelled internal standards (ILIS) was investigated to correct unsatisfactory values. Up to 12 ILIS were evaluated in EWW and surface water (SW). As expected, the ILIS provided satisfactory correction for their own analytes. However, the use of these ILIS for the rest of pharmaceuticals was problematic in some cases. Despite this fact, the correction with analogues ILIS was found useful for most of analytes in EWW, while was not strictly required in the SW tested. The method was successfully validated in SW and EWW at low concentration levels, as expected for pharmaceuticals in these matrices (0.025, 0.1 and 0.5 μg/L in SW; 0.1 and 0.5 μg/L in EWW). With only a few exceptions, the instrumental limits of detection varied between 0.1 and 8 pg. The limits of quantification were estimated from sample chromatograms at the lowest spiked levels tested and normally were below 20 ng/L for SW and below 50 ng/L for EWW. The developed method was applied to the analysis of around forty water samples (river waters and effluent wastewaters) from the Spanish Mediterranean region. Almost all the pharmaceuticals selected in this work were detected, mainly in effluent wastewater. In both matrices, analgesics and anti-inflammatories, lipid regulators and quinolone antibiotics were the most detected groups.     

超高效液相色谱-串联质谱联用法同步检测抗生素生产废水中螺旋霉素与新螺旋霉素残留

采用超高效液相色谱-串联质谱法同步测定了抗生素生产废水中残留的螺旋霉素(SPM-Ⅰ)和新螺旋霉素(NSPM-Ⅰ)。考察了萃取溶剂种类、水样pH值、萃取次数、水样与萃取溶剂的体积比等因素对目标物回收率的影响。以ACQUITY UPLC BEH C18(100 mm×2.1 mm i.d.,1.7 μm)为分析柱,0.1%甲酸水溶液和乙腈为流动相梯度淋洗,流速0.2 mL/min,电喷雾正离子多重反应监测模式检测。标准曲线在0.02~1.00 mg/L范围内线性关系良好,r2均大于0.999。方法回收率为70% ~ 88%,相对标准偏差小于10%,检出限(S/N=3)分别为0.03 μg/L(SPM-Ⅰ)和0.06 μg/L(NSPM-Ⅰ)。该方法应用于无锡市某制药厂抗生素生产废水中SPM-Ⅰ和NSPM-Ⅰ的检测,检出质量浓度分别为（115.6±2.7） mg/L和（5.3±0.4） mg/L。     

固相萃取/液相色谱-串联质谱法检测医院废水中21种抗生素药物残留

应用固相萃取及高效液相色谱-串联质谱技术,建立了医院废水中12种磺胺、4种喹诺酮、3种四环素以及罗红霉素和甲氧苄氨嘧啶等21种抗生素的定性定量方法。水样经HLB小柱萃取富集,使用10%甲醇溶液净化,经甲醇洗脱定容后,以高效液相色谱-串联质谱多反应监测离子模式(MRM)对目标物进行分析。在优化实验条件下,21种抗生素的线性范围为1.0～500μg/L,相关系数r2>0.99,方法检出限为0.005～0.022μg/L。在加标量为0.05μg/L和1.0μg/L时,空白加标回收率分别为71%～105%和76%～111%,RSD均小于15%。以医院废水为基质,21种抗生素的加标回收率为71%～135%,RSD小于25%。该方法简捷、快速、准确,能够实现医院废水中多种抗生素药物残留的同时分析。     

Rapid determination of five antibiotic residues in swine wastewater by online solid-phase extraction–high performance liquid chromatography–tandem mass spectrometry

A simple and quick online solid-phase extraction (SPE) coupled to liquid chromatography (LC)/tandem mass spectrometry (MS/MS) for the determination of the five antibiotics (florfenicol, FF; lincomycin, LCM; oxytetracyclin, OTC; tylosin, TS; valnemulin, VLM) in swine wastewater has been developed. After filtration, aliquots (100 μl) of wastewater samples were directly injected to a column-switching LC system. Some matrix interference was removed by washing up SPE column with 0.2% formic acid solution and acetonitrile. Antibiotics eluted from SPE column were separated on analytical column by converting switching valve and were detected by MS/MS. Calibration curves using the method of standard addition had very good correlation coefficients (r > 0.99) in the range of 0.1 to 2 ng/ml. The intra-day precision of the method was less than 12% and the inter-day precision was between 6 to 17%. The detection limits were 0.01–0.1 ng/ml. When this method was applied to wastewater samples in swine facilities, four compounds (LCM, OTC, TS, and VLM) were detected.     

Determination of multi‐class antibiotic residues in compost by microwave‐enhanced accelerated solvent extraction and ultra performance convergence chromatography with tandem mass spectrometry

This work reports the development and application of a multi‐class compound analysis method for the determination of 20 antibiotic residues in compost. Samples were processed by microwave‐enhanced accelerated solvent extraction at 120°C for 7.5 min. Salting‐out homogeneous liquid‐liquid extraction was used to remove water and water‐soluble impurities from the extract before ultra performance convergence chromatography with tandem mass spectrometry analysis. By using the supercritical fluid (carbon dioxide) and organic solvent (methanol) as the mobile phase, the 20 antibiotics and the internal standard were well separated in 8.2 min without obvious matrix effect. Method validation was performed and good trueness (relative error in the range of ±5.0%) and precision (inter‐ and intraday relative standard deviations < 10.8%) were obtained. Method detection and quantitation limits were 0.8–1.9 and 2.7–7.1 ng/g, respectively. Recoveries were assessed at three concentration levels (10, 60, and 400 ng/g) and acceptable mean values (70.4–111.9%) were found. This method has also been used to analyze real samples, and the average concentrations of antibiotics (excepting the concentrations < method quantitation limits) were determined up to 123.6 ng/g. The results showed the method could be helpful for the analysis of multi‐class antibiotics in environmental samples.     

分散液相微萃取/液相色谱串联质谱法快速测定猪尿中的盐酸克伦特罗与氯霉素

采用分散液相微萃取净化技术,建立了快速测定猪尿中盐酸克伦特罗和氯霉素残留的高效液相色谱-串联质谱分析方法.取5 mL猪尿样品,分别加入5 ngD9-盐酸克伦特罗和D5-氯霉素内标,调节pH至10.0,加入10％ NaC1,经250 μL三氯甲烷和750 μL异丙醇分散萃取后离心,转移下层沉淀,氮吹后以甲醇水溶液定容,采...     

超高效液相色谱-串联质谱法同时测定制药废水中10种抗生素

建立了一种同时测定制药废水中3类10种抗生素的超高效液相色谱-串联质谱分析方法。水样用固相萃取柱富集净化,通过比较在不同的固相萃取柱和洗脱液等条件下水样中目标物的回收率,优化了前处理方法。采用Agilent C18色谱柱(75 mm×2.1 mm, 2.7 μm),以0.2%(v/v)甲酸水溶液和乙腈为梯度洗脱的流动相,在电喷雾-多反应监测模式下进行定性定量分析。实验结果表明:在0.1~1000 μg/L范围内,6种氨基糖苷类抗生素、螺旋霉素及3种氟喹诺酮类抗生素的峰面积与质量浓度的线性关系良好(r² > 0.995),方法检出限为0.07~4.37 ng/L,定量限为0.22~14.55 ng/L;目标抗生素的加标水平为0.002~40 μg/L时,平均回收率为50.4%~114.1%,相对标准偏差均不高于9.89%(n=3)。基于上述方法,对江苏省某制药厂废水中相关物质进行检测,在各废水处理单元中检出3种目标抗生素,质量浓度范围为0.46~1033.60 μg/L。该方法准确可靠、灵敏度高,适用于制药厂废水中氨基糖苷类抗生素、螺旋霉素和氟喹诺酮类抗生素的检测。     

Ionic liquid chemically bonded basalt fibers for in‐tube solid‐phase microextraction

Ionic liquids have been widely used in different fields by advantage of their specific properties. In this work, 1‐methyl‐3‐(3‐trimethoxysilyl propyl)imidazolium chloride was prepared and chemically bonded onto basalt fibers for in‐tube solid‐phase microextraction. Through combining in‐tube extraction device with high‐performance liquid chromatography equipped with a diode array detector, an online enrichment and analysis method for eight polycyclic aromatic hydrocarbons was established under the optimum conditions. A good enrichment factor (52–814), good linearity (0.10–15 and 0.20–15 μg/L), low limits of detection (0.03–0.05 μg/L), and low limits of quantitation (0.10–0.20 μg/L) were achieved using a sample volume of 50 mL. Analysis method was applied to the real samples including the groundwater and wastewater from a chemical industry park, some target analytes were detected and the relative recoveries were in the range of 80.4–116.8%.     

Determination of carbapenems in water samples by UHPLC–MS/MS

A rapid and reliable method for the detection of five carbapenems (biapenem, imipenem, doripenem, meropenem, and faropenem) in water was developed and validated. After acidification of water samples with acetic acid, carbapenems were isolated using a Bond Elut PPL cartridge. The target compounds were separated using ultra high performance liquid chromatography with a chromatographic run time of 5 min and detected on a triple quadrupole mass spectrometer operated in positive electrospray ionization and multiple reaction monitoring mode. Mean recoveries were in the range of 76.6–106.5%, with satisfactory intraday and interday relative standard deviations lower than 10.0 and 10.8%, respectively. The limits of detection and quantification were in the ranges of 0.05–0.2 µg/L and 0.1–0.5 µg/L, respectively, depending on the analyte. The proposed method was applied to the analysis of river samples and wastewater samples from swine farms, and no carbapenems were detected in the collected samples.     

QuEChERS结合柱净化的超高效液相色谱-串联质谱法测定有机肥中46种抗生素

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定有机肥中磺胺类、喹诺酮类、大环内酯类46种抗生素的分析方法。样品用乙腈-EDTA缓冲溶液(p H 10.0)提取,盐析后离心分层,乙腈层按Qu ECh ERS法,采用吸附剂净化;缓冲溶液层经HLB柱净化。ACQUITY UPLC BEH C18柱用作色谱分离,以2mmol/L甲酸铵水溶液(含0.1%甲酸)-甲醇为流动相进行梯度洗脱;电喷雾电离源正离子(ESI+)多反应监测(MRM)模式检测,基质外标法定量。46种抗生素在1~200μg/L范围内线性关系良好,相关系数(r2)为0.996 6~0.999 9。在25,100,400μg/kg加标浓度下,3类抗生素的回收率分别为67.8%~95.6%,65.6%~89.4%和66.6%~107.8%,相对标准偏差为0.4%~11.9%;方法检出限(S/N=3)为0.6~4.6μg/kg,定量下限(S/N=10)为2.1~15.4μg/kg。     

高效液相色谱-串联质谱快速测定饲料中硝基咪唑类药物及其代谢物残留

建立了高效液相色谱-串联质谱快速测定饲料中甲硝唑(MNZ)、甲硝唑代谢物(MNZOH)、二甲硝咪唑(DMZ)、二甲硝咪唑代谢物(HMMNI)、洛硝哒唑(RNZ)、异丙硝唑(IPZ)、异丙硝唑代谢物(IPZOH)残留的分析方法。样品经0.1 mol/L pH 8.0磷酸盐缓冲液和乙酸乙酯-丙酮(70∶30)提取,提取液经分散型固相萃取填料N-丙基乙二胺(PSA)净化后,再经正己烷脱脂,液-液分配净化,采用电喷雾电离源(ESI)正离子多反应监测(MRM)模式检测,氘代同位素内标法定量。该方法省去耗时的固相萃取过程,快速、简单、高效,7种目标分析物在2.0~100.0μg/L范围内线性关系良好,相关系数大于0.99,在5.0~25.0μg/kg范围内,3个加标水平的回收率为72.4%~95.6%,相对标准偏差(RSD)均小于12.5%;检出限为2.5μg/kg,定量下限为5.0μg/kg。     

Multiresidue LC–MS/MS analysis of cephalosporins and quinolones in milk following ultrasound‐assisted matrix solid‐phase dispersive extraction combined with the quick,easy, cheap,effective, rugged,and safe methodology

A sensitive and selective confirmatory method for milk‐residue analysis of ten quinolones and eight cephalosporins by LC‐MS/MS has been developed herein. For the chromatographic separation of target analytes, a Perfectsil ODS‐2 (250 × 4 mm, 5 μm) analytical column was used and gradient elution was applied, using a mobile phase of 0.1% w/w TFA in water and 0.1% w/w TFA in ACN. Ultrasound‐assisted matrix solid‐phase dispersion procedure was applied for the extraction and clean‐up procedure of antimicrobials agents from milk matrix using a mixture of Bond Elut Plexa sorbent and QuEChERS. The method was validated meeting the European Legislation determining selectivity, linearity response, trueness, precision (repeatability and between‐day reproducibility), decision limit, detection capability, and ruggedness following the Youden approach. Recoveries of all antibiotics ranged from 81.7 to 117.9%, while RSD values were lower than 13.7%. Limits of quantification for all examined compounds ranged from 2.4 to 15.0 μg/kg, substantially lower than the maximum residue limits established by the European Union (30–100 μg/kg).     

Combination of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and dispersive liquid-liquid microextraction in the identification and determination of pesticides from various classes in food products by gas-liquid chromatography

A procedure for the identification (104 substances) and determination (40 substances) of the active components of combined pesticides from different classes in water, vegetables, fruits, and meat by gas chromatography with mass-spectrometric and electron-capture detectors was proposed. The pesticides were extracted from the samples of vegetables, fruits, and meat with acetonitrile using the QuEChERS method. The extracts were preconcentrated by a factor of 50–60 and additionally purified by dispersive liquid-liquid microextraction. The pesticides were extracted from water by dispersive liquid-liquid microextraction with hexane (degree of concentration was higher than 100). The limits of detection by the time-of-flight detector equaled 0.01–0.02 mg/kg for solid samples and 1–2 μg/L for aqueous solutions. The limits of quantitation for pesticides were 1–2 mg/kg for solid samples and 0.05–0.1 μg/L for solutions. The analysis time was 1–2 h, and the RSD of the results did not exceed 18%.     

Qualitative-quantitative analysis of multi-mycotoxin in milk using the high-performance liquid chromatography-tandem mass spectrometry coupled with the quick,easy, cheap,effective, rugged and safe method

High-performance liquid chromatography-tandem mass spectrometry coupled with the quick, easy, cheap, effective, rugged and safe method was established for the qualitative and quantitative detections of 20 mycotoxins in milk. The linear range of this method was 0.01–10 μg/L and the correlation coefficients were all greater than or equal to 0.9933. At three levels of addition, the spiked recoveries ranged from 80.00 to 112.50%, relative standard deviations were 2.67–14.97%, limits of quantitation were 0.02–4.00 μg/kg, and limits of detection were 0.007–1.300 μg/kg. This developed procedure for the identification and quantitation of mycotoxins provided prospective support for quality regulation.     

Development and validation of a rapid and wide-scope qualitative screening method for detection and identification of organic pollutants in natural water and wastewater by gas chromatography time-of-flight mass spectrometry

In this work, a multiclass screening method for organic contaminants in natural and wastewater has been developed and validated for qualitative purposes, i.e. to ensure the reliable and sensitive identification of compounds detected in samples at a certain level of concentration. The screening is based on the use of GC-TOF MS, and the sample procedure involves solid phase extraction with C(18) cartridges. Around 150 organic contaminants from different chemical families were investigated, including PAHs, octyl/nonyl phenols, PCBs, PBDEs and a notable number of pesticides, such as insecticides (organochlorines, organophosphorus, carbamates and pyrethroids), herbicides (triazines and chloroacetanilides), fungicides and several relevant metabolites. Surface water, ground water and effluent wastewater were spiked with all target analytes at three concentration levels (0.02, 0.1 and 1 μg/L). Influent wastewater and raw leachate from a municipal solid waste treatment plant were spiked at two levels (0.1 and 1 μg/L). Up to five m/z ions were evaluated for every compound. The identification criterion was the presence of, at least, two m/z ions at the expected retention time, measured at their accurate mass, and the accomplishment of the Q/q(i) intensity ratio within specified tolerances. The vast majority of compounds investigated were correctly identified in the samples spiked at 1 μg/L. When analyte concentration was lowered down to 0.1 μg/L the identification was more problematic, especially in complex-matrix samples like influent wastewater. On the contrary, many contaminants could be properly identified at the lowest level 0.02 μg/L in cleaner matrices. The procedure was applied to the screening of water samples of different origin and matrix composition and allowed the detection of several target contaminants. A highly reliable identification could be carried out thanks to the sensitive full-spectrum acquisition at accurate mass, the high selectivity reached with the use of narrow-mass window extracted ion chromatograms, the low mass errors observed in the positive detections and the Q/q ratio accomplishment.     

Polyaniline-co-polyindole functionalized magnetic porous carbon derived from MIL-53(Fe) for separation/enrichment of nitrophenols pollutants before determination with high-performance liquid chromatography-ultraviolet detection

Herein, a novel polyaniline-co-polyindole functionalized magnetic porous carbon derived from MIL-53(Fe) was prepared and employed as an excellent nano-adsorbent to preconcentrate trace amounts of nitro-phenols in water and wastewater samples. Briefly, magnetic MIL-53(Fe) was synthesized by the addition of magnetite nanoparticles, terephthalic acid, and FeCl₃ to the reaction medium. The magnetic MIL-53(Fe) was pyrolyzed under nitrogen protection to obtain a magnetic porous carbon nanocomposite, and finally, the nanomaterial was functionalized with polyaniline-co-polyindole via oxidation polymerization. The obtained nano-adsorbent was characterized via X-ray diffraction, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and transmission and scanning electron microscopies. After that, the fabricated nano-material was utilized as an excellent nano-adsorbent for the preconcentration of trace nitro-phenols (2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol) in environmental water, and wastewater samples. The detection limits were obtained from 0.1 to 0.15 μg/L after performing the optimization process. The new method was in the range of 0.4–300 μg/L. The proposed method exhibited a good precision from 3.2% to 9.6% for within-day assay, and 5.2%–13.2% for between-day assay at three concentration levels (1, 50, and 250 μg/L). Eventually, this method was utilized to preconcentrate/determine the target analytes in three water, and wastewater samples, satisfactory (relative standard deviations, 5.4%–9.3%; relative recovery, 88%–109%).