Danijela Ašperger

Solid Phase Extraction and HPLC Determination of Veterinary Pharmaceuticals in Wastewater

This work focuses on the application of SPE-HPLC analysis of important veterinary pharmaceuticals from different classes in highly complex wastewater matrix. The pharmaceutical investigated included three sulfonamides (sulfamethazine, sulfadiazine and sulfaguanidine), a sulfonamide synergist (trimethoprim), a tetracycline (oxytetracycline), a fluoroquinolone (enrofloxacine) and a beta-lactame (penicillin G/procaine). The method involves pre-concentration and clean-up by solid phase extraction (SPE) using Oasis HLB extraction catridges. Final analysis of the selected pharmaceutical compounds was carried out by high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD). Recoveries were ranged from 68.3 to 97.9% with relative standard deviation below 8.4%. Only for sulfaguanidine low recovery was obtained. Limits of quantification were in the range 1.5-100mug/L depending on pharmaceutical. The described method was applied to the determination of pharmaceuticals in wastewater samples from pharmaceutical industry.

Effect of water matrices on removal of veterinary pharmaceuticals by nanofiltration and reverse osmosis membranes

This study explored the removal of five veterinary pharmaceuticals (VPs) (sulfamethoxazole (SMETOX), trimethoprim (TMP), ciprofloxacin (CIPRO), dexamethasone (DEXA) and febantel (FEBA)) from different water matrices (Milli-Q water, model water, tap water and real pharmaceutical wastewater using four types of nanofiltration (NF) membranes (NF90, NF270, NF and HL) and two reverse osmosis (RO) membranes (LFC-1 and XLE). All VPs were added to different water matrices at a concentration of 10 mg/L. Rejections of VPs and water flux were measured. The rejection increased with increase of molecular weight. The highest rejections were obtained with RO membranes (LFC-1, XLE) and tight NF (NF90) membrane. In general, the rejection of VPs was higher in model water and tap water than in Milli-Q water, but the water flux was lower. This was mainly explained by ion adsorption inside the membranes pores. Narrower pore size counteracted the effect of presence of low concentration of natural organic matter (NOM) in tap water. The NOM was assumed to enhance the adsorption of VPs onto membrane surface, increased the size exclusion and electrostatic repulsion also appeared during the transport. Investigated water matrices had influence on water flux decline due to their complexity.

Development and optimization of the SPE procedure for determination of pharmaceuticals in water samples by HPLC-diode array detection.

This paper focuses on the investigation of different types of SPE sorbents for the preconcentration of eight veterinary pharmaceuticals from water samples. The pharmaceuticals studied were sulfamethazine, sulfadiazine, sulfaguanidine, trimethoprim, oxytetracycline, enrofloxacin, norfloxacin and penicillin G/procaine. Five different SPE materials (Strata-X, Strata-X-C, Strata SDB-L, Strata C8 and Strata C18) from Phenomenex were compared with Oasis HLB with a view to obtaining the best cartridges for all pharmaceuticals investigated. Extraction efficiency was determined by HPLC with diode array detection (DAD). HPLC-DAD separation and quantification of the selected pharmaceuticals were carried out under gradient elution by a binary mixture of 0.01 M oxalic acid and ACN based on cyano modified column (LiChrosphere 100 CN) from Merck. Strata-X provided the best results in the preconcentration of 100 mL water samples, yielding average pharmaceutical recoveries of higher than 90%, except for sulfaguanidine (76.1%). The developed Strata-X-HLPC-DAD method was validated and applied, for the efficient investigation of reverse osmosis/nanofiltration membranes and for the removal of these eight pharmaceuticals from the production wastewater samples. NF90 and XLE membranes were shown to be the best for the rejection of all investigated pharmaceuticals.

RO/NF membrane treatment of veterinary pharmaceutical wastewater: comparison of results obtained on a laboratory and a pilot scale

BackgroundEmerging contaminants (ECs) are commonly derived from industrial wastewater, which is often a consequence of an inadequate treatment of the latter. Improperly pretreated pharmaceutical wastewater could cause difficulties in operations of wastewater treatment plants while incomplete elimination of ECs during the processing might result in their appearance in drinking water.MethodsThis paper deals with membrane treatment of pharmaceutical wastewater on a laboratory and a pilot scale as well as with the removal of the following veterinary pharmaceuticals (VPs) (sulfamethoxazole, trimethoprim, ciprofloxacin, dexamethasone, and febantel).ResultsThe pretreatment of pharmaceutical wastewater by means of coagulation and microfiltration (MF) prevented the irreversible fouling of the fine porous structure of the reverse osmosis (RO) and nanofiltration (NF) membranes which were used in the final stage of wastewater processing. The percentage of the removal of the selected VPs ranges from 94% to almost 100% in the case of NF and RO membranes in both scales. The recovery percentage concerning the pilot scale amounted to 88%. Membrane cleaning was successfully carried out in both scales.ConclusionsThe differences in retention between laboratory and pilot tests are due to different raw wastewater quality and different recovery and hydrodynamic of the two systems. Fouling and concentration polarization were more pronounced in laboratory setup (frame-plate module) than in pilot unit (spiral module). The proposed integrated membrane treatment (coagulation, MF, NF, and RO) can be employed for treatment of wastewater originating from pharmaceutical factory. The obtained permeate can be safely discharged to sewer system or could be reused in manufacturing process.

SPE-HPLC/DAD determination of trimethoprim, oxytetracycline and enrofloxacin in water samples

In this paper high-performance liquid chromatography with diode array UV detection (HPLC/DAD) after SPE sample pretreatment for simultaneous analysis of pharmaceuticals from three different classes: enrofloxacin, oxytetracycline and trimethoprim, has been developed, optimised and validated. The chromatographic separation was developed on spiked wellspring water samples and checked on model wastewater samples of veterinary pharmaceuticals before and after RO/NF membrane treatment (feed and permeate streams) and on process wastewaters of industrial origin. Chromatographic separation was performed on Varian ProStar HPLC/DAD with C-18 column (Microsorb-MV 100 C18, 150 × 4.6 mm; 5 µm, Varian, USA). Detection and quantification was performed at 254 nm. The best separation was achieved with mobile phase 0.5% formic acid and 1% trifluoroacetic acid in 0.05 M ammonium acetate-methanol, 70 + 30, (v/v) after extraction procedure on polystyrenedivinylbenzene Varian Empore extraction disks. The extraction efficiency was checked by recovery experiments.

Comparison of Different Solid-Phase Extraction Materials for Sample Preparation in the Analysis of Veterinary Drugs in Water Samples

This paper focuses on the study of different types of SPE material that can be used for preconcentration of eight pharmaceuticals from water samples. The compounds studied were enrofloxacine, norfloxacine, Oxytetracycline, trimethoprim, sulfamethazine, sulfadiazine, sulfaguanidine, and penicillin G/procaine. Cartridges were tested on spiked water samples and extraction efficiency was determined by thin-layer chromatography (TLC) CN-modified chromatographic plates with 0.05 m H2C2O4-methanol, 81 + 19, as mobile phase. Strata-X cartridges were proved to be the best type of SPE material for this group of pharmaceutical compounds. For this reason an SPE—TLC method with Strata-X cartridges and HPTLC plates was validated. The method has been applied to the determination of pharmaceutical products in production wastewater samples from the pharmaceutical industry.

Recovery of Flavonoids from Grape Skins by Enzyme- Assisted Extraction

Abstract Grape skin contains large amounts of different flavonoids so it can be used for their recovery. Optimization of enzyme-assisted extraction of flavonoids was conducted using oenological enzyme preparations with respect to enzyme dosage, temperature, extraction time, pH, and enzyme preparation. Optimal conditions were obtained using enzyme preparation Lallzyme EX-V, at the temperature of 45°C, time of 3 h, pH 2.0, and enzyme dosage of 10.52 mg/g. The new optimized extraction method is less expensive, simple, accurate, and selective for the recovery of simple flavonoids. It is based on an environmentally-friendly extraction solvent which may provide a valuable alternative to conventional methods.

Development and optimization of the determination of pharmaceuticals in water samples by SPE and HPLC with diode-array detection

This paper describes the development, optimization, and validation of a method for the determination of five pharmaceuticals from different therapeutic classes (antibiotics, anthelmintics, glucocorticoides) in water samples. Water samples were prepared using SPE and extracts were analyzed by HPLC with diode-array detection. The efficiency of 11 different SPE cartridges to extract the investigated compounds from water was tested in preliminary experiments. Then, the pH of the water sample, elution solvent, and sorbent mass were optimized. Except for optimization of the SPE procedure, selection of the optimal HPLC column with different stationary phases from different manufacturers has been performed. The developed method was validated using spring water samples spiked with appropriate concentrations of pharmaceuticals. Good linearity was obtained in the range of 2.4-200 μg/L, depending on the pharmaceutical with the correlation coefficients >0.9930 in all cases, except for ciprofloxacin (0.9866). Also, the method has revealed that low LODs (0.7-3.9 μg/L), good precision (intra- and interday) with RSD below 17% and recoveries above 98% for all pharmaceuticals. The method has been successfully applied to the analysis of production wastewater samples from the pharmaceutical industry.

Solid-phase extraction and TLC quantification of enrofloxacin, oxytetracycline, and trimethoprim in wastewater

Quantitative determination of the antibiotics enrofloxacin, oxytetracycline, and trimethoprim in aquatic samples is reported. The method involves solid-phase extraction (SPE) and preconcentration of the antibiotics, separation by thin-layer chromatography (TLC) and quantification by video densitometry. TLC separation was performed on HPTLC CN F254s plates with H2C2O4-methanol as mobile phase. Spots were detected and quantified at X - 254 nm by videodensitometry. Limits of detection (LOD) and limits of quantification (LOQ) for TLC determination were calculated. The method was evaluated for spiked water samples. Antibiotics were extracted by solid-phase extraction (SPE) on a polystyrene-divinyl-benzene (SDB) Empore extraction disk. The extraction efficiency was checked by recovery experiments.

Determination of sulfonamides and trimethoprim in spiked water samples by solid-phase extraction and thin-layer chromatography

This paper describes a method for separation and quantification of a mixture of antibiotics extracted from spiked water samples. The method involves SPE of the analytes from water then analysis of the extract by TLC. Excellent separation of sulfadimidine, sulfadiazine, sulfaguanidine, and trimethoprim (TMP) was achieved by HPTLC on silica gel F254 plates with chloroform-methanol, 89 + 11, as mobile phase. Videodensitometric quantification was validated for linearity, precision, limit of detection, and limit of quantification. Limit of detection (LOD) was 0.05 µg per spot for sulfadimidine, sulfadiazine, and sulfaguanidine, and 0.1 µg per spot for TMP. Limit of quantification (LOQ) was 0.1 µg per spot for sulfadimidine, sulfadiazine, and sulfaguanidine, and 0.2 µg per spot for TMP. The TLC method was tested on extracts obtained, by use of solid-phase extraction, from spiked water samples. The best recovery of these antibiotics was achieved by use of HLB cartridges and elution with acetonitrile. Apparent recoveries were 87.1 ± 8.4 for sulfadiazine, 93.1 ± 6.4 for sulfadimidine, 16.1 ± 7.2 for sulfaguanidine, and 108.7 ± 23.7 for trimethoprim.