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

Determination of 38 antibiotics in raw and treated wastewater from swine farms using liquid chromatography-mass spectrometry

The present study firstly aimed at developing a multi-residue method to identify and quantify 38 veterinary antibiotics (belonging to 5 different classes) not only for raw swine wastewater but also for wastewater different treated by different units. The proposed method is based on a solid-phase extraction procedure and ultra-performance liquid chromatography with mass spectrometry. For sample preparation, the optimal loading sample volume was selected as 50 mL, whose pH was adjusted to approximately 3.0 using formic acid. Then 0.1 g/L ethylenediamine tetraacetic acid disodium salt was added. The recovery rates for different types of wastewaters were in the range of 35.94%-124.51% and the relative standard deviations were in the range of 0.36%-14.62%. All the matrix standard curves exhibited high linearity (0.9956-0.9999). The matrix effects for the target antibiotics ranged from -61.73% to +148.75%. To ensure practicality of the method, we performed the detection of the actual added concentration to determine method detection limits and quantitation limits. The quantitation limits of most of the target antibiotics were 0.04 μg/L, except for spiramycin (0.1 μg/L) and roxithromycin (0.2 μg/L). This optimized and validated method was applied to analyze antibiotic residues in swine water samples from 4 swine farms. This article is protected by copyright. All rights reserved.

On-line solid-phase extraction of pharmaceutical compounds from wastewater treatment plant samples using restricted access media in column-switching liquid chromatography-tandem mass spectrometry

An on-line solid phase extraction using a lab-made restricted access media (RAM) was developed as sample preparation procedure for determination of the pharmaceutical compounds caffeine (CAF), carbamazepine (CBZ), norfloxacin (NOR), ciprofloxacin (CIP), fluoxetine (FLX) and venlafaxine in wastewater treatment plant samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This method is suitable for use in routine of analysis, avoiding cross-contamination and requiring only a small sample volume (50 µL), with minimal handling. The method was validated according to international guidelines. The chromatographic efficiency was evaluated using peak resolution and asymmetry parameters. Carryover was also evaluated, in order to ensure reliability of the analysis and the ability to reuse the cartridge. Satisfactory linearity (r² > 0.99) was obtained for all the compounds. The intra- and inter-day precision values were lower than 5.79 and 14.1%, respectively. The limits of detection ranged from 0.01 to 3 µg L^-1 and the limits of quantification were from 0.1 to 5 µg L^-1. The method was applied to 20 environmental wastewater samples, with caffeine being the most widely detected compound, at the highest concentration of 392 µg L^-1, while other compounds were detected in fewer samples at lower concentrations (up to 9.60 µg L^-1). The lab-made modification is a cheaper option for on-line sample preparation, compared to commercially available on-line SPE cartridges and RAM columns. Moreover, a high-throughput procedure was achieved, with an analysis time of 16 min including sample preparation and chromatographic separation. The same RAM column was applied over 200 injections including method optimization, validation and application in wastewater samples without loss of analytical response.

Oxygen-Resistant Electrochemiluminescence System with Polyhedral Oligomeric Silsesquioxane

We report the oxygen-resistant electrochemiluminescence (ECL) system from the polyhedral oligomeric silsesquioxane (POSS)-modified tris(2,2'-bipyridyl)ruthenium(II) complex (Ru-POSS). In electrochemical measurements, including cyclic voltammetry (CV), it is shown that electric current and ECL intensity increase in the mixture system containing Ru-POSS and tripropylamine (TPrA) on the indium tin oxide (ITO) working electrode. The lower onset potential (E_onset) in CV is observed with Ru-POSS compared to tris(2,2'-bipyridyl)ruthenium(II) complex (Ru(bpy)₃²⁺). From the series of mechanistic studies, it was shown that adsorption of Ru-POSS onto the ITO electrode enhances TPrA oxidation and subsequently the efficiency of ECL with lower voltage. Moreover, oxygen quenching of ECL was suppressed, and it is proposed that the enhancement to the production of the TPrA radical could contribute to improving oxygen resistance. Finally, the ECL-based detection for water pollutant is demonstrated without the degassing treatment. The commodity system with Ru(bpy)₃²⁺ is not applicable in the absence of degassing with the sample solutions due to critical signal suppression, meanwhile the present system based on Ru-POSS was feasible for estimating the amount of the target even under aerobic conditions by fitting the ECL intensity to the standard curve. One of critical disadvantages of ECL can be solved by the hybrid formation with POSS.

Rapid determination of 12 antibiotics and caffeine in sewage and bioreactor effluent by online column-switching liquid chromatography/tandem mass spectrometry

This study presents a column-switching solid-phase extraction online-coupled to a liquid chromatography/tandem mass spectrometry (SPE-LC-MS/MS) method for simultaneous analysis of 12 antibiotics (7 sulfonamides and 5 fluoroquinolones) and caffeine detected in the sewage and effluent of a pilot anaerobic reactor used in sewage treatment. After acidification and filtration, the samples were directly injected into a simple and conventional LC system. Backflush and foreflush modes were compared based on the theoretical plates and peak asymmetry observed. The method was tested in terms of detection (MDL) and quantification limit (MQL), linearity, relative recovery, and precision intra- and inter-day in lab-made sewage samples. The method presented suitable figures of merit in terms of detection, varying from 8.00 × 10(-5) to 6.00 × 10(-2) ng (0.800 up to 600 ng L(-1); caffeine) with direct injection volume of only 100 μL and 13 min of total analysis time (sample preparation and chromatographic run). When the method was applied in the analysis of sewage and effluent of the anaerobic reactor (n = 15), six antibiotics and caffeine were detected in concentrations ranging from 0.018 to 1097 μg L(-1). To guarantee a reliable quantification, standard addition was used to overcome the matrix effect.

Simultaneous determination of florfenicol with its metabolite based on modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and evaluation of their degradation behavior in agricultural soils

A simple and simultaneous method for the determination of florfenicol and its metabolite florfenicol amine in agricultural soils using modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and reversed-phase high-performance liquid chromatography with tandem mass spectrometry is presented. Florfenicol and its metabolite florfenicol amine residues in agricultural soils were extracted with alkalized acetonitrile and an aliquot was cleaned up with Si(CH2)3NH(CH2)2NH2 and C18 sorbent, which were powder materials. High-performance liquid chromatography with tandem mass spectrometry was applied to simultaneously determine the level of florfenicol and florfenicol amine in agricultural soils. Excellent linearity was achieved for florfenicol and florfenicol amine over a range of concentrations from 0.1-500 μg/L with coefficients more than 0.99. Average recoveries at four different levels (0.005, 0.05, 0.5, and 5.0 mg/kg) for florfenicol and florfenicol amine ranged from 73.6-94.9% with relative standard deviations of 2.9-12.5%. The limits of detection for florfenicol and florfenicol amine in agricultural soils were 2.0 μg/kg, and the limits of quantification were 6.0 μg/kg. Based on this method, the degradation behavior of florfenicol and its metabolite florfenicol amine in three soils (Nanchang, Hangzhou, and Changchun) under sterilized and native conditions was investigated and the transformation rate of florfenicol amine from florfenicol was evaluated.

Use patterns, excretion masses and contamination profiles of antibiotics in a typical swine farm, south China

The objective of this study was to screen the occurrence of 50 antibiotics in a typical swine farm in southern China, which includes animal feeds, waste collection and treatment systems (lagoons and anaerobic digesters), and receiving environments (vegetable fields, streams, and private wells). Nine antibiotics were found in the feeds for different stages of the development of pigs in the swine farm, at concentrations ranging from 2.37 ± 0.16 ng g(-1) (sulfamethazine) to 61 500 ± 11 900 ng g(-1) (bacitracin). 11, 17 and 15 target compounds were detected in feces, flush water, and suspended particles in the swine farm, respectively. Based on the survey of feeds and animal waste from the farm, chlortetracycline, tetracycline, bacitracin and florfenicol in the feces, flush water and suspended particles mainly originated from the feeds, while most sulfonamides, including doxycycline, oxytetracycline, fluoroquinolones, macrolides and trimethoprim, were mainly from injection and other oral routes. The daily excretion masses of antibiotics per pig calculated based on animal waste had the following order: sows (48.3 mg per day per pig), piglets (18.9 mg per day per pig), growing pigs (7.01 mg per day per pig) and finishing pigs (1.47 mg per day per pig), indicating that the usage of antibiotics (type and dosage) and excretion masses are related to the growth stage of pigs. Chlortetracycline and bacitracin are the main contributors to the total excretion mass of antibiotics from pigs at different stages of development in the farm. The waste treatment system (lagoons and anaerobic digesters) was found to be ineffective in the elimination of antibiotics. The detection of some antibiotics in the surrounding environments of the farm (the well water, stream water and vegetable field soil) was a reflection of pollution from the swine farm.

Excretion masses and environmental occurrence of antibiotics in typical swine and dairy cattle farms in China

This paper evaluated the excretion masses and environmental occurrence of 11 classes of 50 antibiotics in six typical swine and dairy cattle farms in southern China. Animal feeds, wastewater and solid manure samples as well as environmental samples (soil, stream and well water) were collected in December 2010 from these farms. Twenty eight antibiotics, including tetracyclines, bacitracin, lincomycin, sulfonamides, fluoroquinolones, ceftiofur, trimethoprim, macrolides, and florfenicol, were detected in the feeds, animal wastes and receiving environments. The normalized daily excretion masses per swine and cattle were estimated to be 18.2mg/day/swine and 4.24 mg/day/cattle. Chlortetracycline (11.6 mg/day/swine), bacitracin (3.81 mg/day/swine), lincomycin (1.19 mg/day/swine) and tetracycline (1.04 mg/day/swine) were the main contributors to the normalized daily excretion masses of antibiotics per swine, while chlortetracycline (3.66 mg/day/cattle) contributed 86% of the normalized daily excretion masses of antibiotics per cattle. Based on the survey of feeds and animal wastes from the swine farms and interview with the farmers, antibiotics excreted by swine were mainly originated from the feeds, while antibiotics excreted by dairy cattle were mainly from the injection route. If we assume that the swine and cattle in China excrete the same masses of antibiotics as the selected livestock farms, the total excretion mass by swine and cattle per annum in China could reach 3,080,000 kg/year and 164,000 kg/year. Various antibiotics such as sulfonamides, tetracyclines, fluroquinolones, macrolides, trimethoprim, lincomycin and florfenicol were detected in well water, stream and field soil, suggesting that livestock farms could be an important pollution source of various antibiotics to the receiving environments.

Multiresidue analysis of 88 polar organic micropollutants in ground, surface and wastewater using online mixed-bed multilayer solid-phase extraction coupled to high performance liquid chromatography-tandem mass spectrometry

An automated multiresidue method consisting of an online solid-phase extraction step coupled to a high performance liquid chromatography-tandem mass spectrometer (online-SPE-HPLC-MS/MS method) was developed for the determination of 88 polar organic micropollutants with a broad range of physicochemical properties (logD(OW) (pH 7): -4.2 to 4.2). Based on theoretical considerations, a single mixed-bed multilayer cartridge containing four different extraction materials was composed for the automated enrichment of water samples. This allowed the simultaneous analysis of pesticides, biocides, pharmaceuticals, corrosion inhibitors, many of their transformation products, and the artificial sweetener sucralose in three matrices groundwater, surface water, and wastewater. Limits of quantification (LOQs) were in the environmentally relevant concentration range of 0.1-87 ng/L for groundwater and surface water, and 1.5-206 ng/L for wastewater. The majority of the compounds could be quantified below 10 ng/L in groundwater (82%) and surface water (80%) and below 100 ng/L in wastewater (80%). Relative recoveries were largely between 80 and 120%. Intraday and inter-day precision, expressed as relative standard deviation, were generally better than 10% and 20%, respectively. 50 isotope labeled internal standards were used for quantification and accordingly, relative recoveries as well as intraday and inter-day precision were better for compounds with corresponding internal standard. The applicability of this method was shown during a sampling campaign at a riverbank filtration site for drinking water production with travel times of up to 5 days. 36 substances of all compound classes investigated could be found in concentrations between 0.1 and 600 ng/L. The results revealed the persistence of carbamazepine and sucralose in the groundwater aquifer as well as degradation of the metamizole metabolite 4-acetamidoantipyrine.

Occurrence of ciprofloxacin, enrofloxacin, and florfenicol in animal wastewater and water resources

Antimicrobial agent residues are becoming an intractable environmental problem in soil, surface, and underground water. To obtain a broad profile of residues in animal wastewater and surface water, 24 animal wastewater, 8 animal farm effluent, 18 river water, and 8 pond water samples taken in Jiangsu in eastern China were monitored for enrofloxacin, ciprofloxacin, and florfenicol using solid phase extraction and high performance liquid chromatography/electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS) techniques. The results revealed that two antibacterials were detected simultaneously in 49.1% of samples, followed by three antibacterials (22.6%) and one antibacterial (22.6%). Up to 3.35, 5.93, and 2.10 μg L for ciprofloxacin, 1.09, 4.24, and 0.50 μg L for enrofloxacin, and 0.95, 2.40, and 2.84 μg L for florfenicol were detected in animal farm-effluent, river, and pond water, respectively. The maximum concentrations of ciprofloxacin and enrofloxacin in animal wastewaters were 7.49 and 8.77 μg L, respectively. Furthermore, residue levels of ciprofloxacin and florfenicol showed at least two statistical differences between any two sampling areas or two animal farms. Enrofloxacin showed no statistical difference among the sampling areas and the animal farms.

Potential of Phragmites australis for the removal of veterinary pharmaceuticals from aquatic media

The potential of Phragmites australis was evaluated for the removal of three veterinary drugs, enrofloxacin (ENR), ceftiofur (CEF) and tetracycline (TET), from aquatic mediums. Results showed that the plant promoted the removal of 94% and 75% of ENR and TET, respectively, from wastewater. Microbial abundance estimation revealed that microorganisms were not a major participant. Occurrence of drugs adsorption to plant roots was observed in small extension. Therefore, main mechanisms occurring were drug removal by plant uptake and/or degradation. Present results demonstrated the potential of P. australis-planted beds to be used for removal of pharmaceuticals from livestock and slaughterhouse industries wastewater.

Determination of tylosins A, B, C and D in bee larvae by liquid chromatography coupled to ion trap-tandem mass spectrometry

A LC-MS/MS method has been developed to simultaneously quantify tylosins A, B, C and D in bee larvae, compounds currently used to treat one of the most lethal diseases affecting honey bees around the world, American Foulbrood (AFB). The influence of different aqueous media, temperature and light exposure on the stability of these four compounds was studied. The analytes were extracted from bee larvae with methanol and chromatographic separation was achieved on a Luna C(18) (150 × 4.6 mm i.d.) using a ternary gradient composed of a diluted formic acid, methanol and acetonitrile mobile phase. To facilitate sampling, bee larvae were initially dried at 60°C for 4h and afterwards, they were diluted to avoid problems of pressure. MSD-Ion Trap detection was employed with electrospray ionization (ESI). The calibration curves were linear over a wide range of concentrations and the method was validated as sensitive, precise and accurate within the limits of quantification (LOQ, 1.4-4.0 ng/g). The validated method was successfully employed to study bee larvae in field tests of bee hives treated with two formulations containing tylosin. In both cases it was evident that the minimal inhibitory concentration (MIC) had been reached.

Fully automated determination of 74 pharmaceuticals in environmental and waste waters by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry

The present work describes the development of a fully automated method, based on on-line solid-phase extraction (SPE)-liquid chromatography-electrospray-tandem mass spectrometry (LC-MS-MS), for the determination of 74 pharmaceuticals in environmental waters (superficial water and groundwater) as well as sewage waters. On-line SPE is performed by passing 2.5 mL of the water sample through a HySphere Resin GP cartridge. For unequivocal identification and confirmation two selected reaction monitoring (SRM) transitions are monitored per compound, thus four identification points are achieved. Quantification is performed by the internal standard approach, indispensable to correct the losses during the solid phase extraction, as well as the matrix effects. The main advantages of the method developed are high sensitivity (limits of detection in the low ng L(-1) range), selectivity due the use of tandem mass spectrometry and reliability due the use of 51 surrogates and minimum sample manipulation. As a part of the validation procedure, the method developed has been applied to the analysis of various environmental and sewage samples from a Spanish river and a sewage treatment plant.

Perfluorinated compounds (PFCs) in groundwater and aqueous soil extracts: using inline SPE-LC-MS/MS for screening and sorption characterisation of perfluorooctane sulphonate and related compounds

Perfluorinated compounds (PFCs) have been recognised as emerging pollutants of global relevance. A fully automated method with inline solid-phase extraction coupled to electrospray ionisation liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) is presented and used for characterisation of soil adsorption and desorption for six PFCs: perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorobutane sulphonate (PFBS), and perfluorooctane sulphonate (PFOS). The method reduces sample turnaround time and solvent consumption and is suitable for low volume sampling. The only sample preparation necessary for water samples was sedimentation by centrifugation. The method has a total runtime of 21 min including inline sample cleanup (2 min for injection and SPE, 14 min for the chromatographic separation, 5 min for reconditioning). Negative AP-ESI with selective reaction monitoring (SRM) was used and the method was documented for quantification of the six environmentally important PFCs in subsoil matrix and related aqueous matrixes (groundwater and drainage water). Linearity was demonstrated in the range 5 to 2,500 ng/l and the LOD was between 2 and 8 ng/l in groundwater. Adsorption was characterised by linear Freundlich isotherms for all six compounds in two agricultural top soils (A horizon, sandy and clayey soil).Variability in sorption characteristics for soil types as well as compound properties were found, and correlation between the organic carbon normalised sorption coefficient (K (OC)) and PFC molecular weight was demonstrated. The K (d) values were in the range 0.1 to 33 (l/kg), and 0.3 to 65 (l/kg) for sorption and desorption respectively.