Ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction coupled with liquid chromatography-quadrupole-linear ion trap-mass spectrometry for simultaneous analysis of pharmaceuticals in wastewaters

Microwave-Assisted Dispersive Liquid-Liquid Microextraction Combined with HPLC for the Determination of Three Biogenic Amines in Beverages

Microwave-assisted dispersive liquid-liquid microextraction (MADLLME) coupled with high-performance liquid chromatography (HPLC) with diode array detector was used for the extraction and determination of three biogenic amines (BAs), including tryptamine, histamine and phenylethylamine in beverages (beer, cherry juice and white spirit). Compared with solid-phase extraction, solid-phase microextraction and liquid-phase microextraction, which is more solvent use with lower extraction efficiency, this MADLLME method obviously shortened analytical time, the rapid heating of aqueous samples with non-ionizing electromagnetic radiation, a lower solvent use and enhanced extraction efficiency. Because of good extraction for three BAs, [3C6PC14][FeCl4] was used as an extraction solvent. We showed a tunable selectivity of magnetic ionic liquids (MILs) toward extracting BAs by changing anion or cation due to the modification of the interaction between the MIL and the BAs. Extraction conditions including the type and volume of extraction solvent, microwave power, microwave-assisted extraction time, sample pH, disperser and interference experiment were investigated. Under the optimal conditions, a good linear relationship was found in the concentration range of 100-2,000 ng mL-1 for three BAs with correlation coefficient (R2) of 0.995-0.999. The limit of detections (S/N = 3) and limit of quantitations (S/N = 10) were in the range of 3.46-4.96 ng mL-1 and 10.44-14.88 ng mL-1, respectively. The recoveries of three targets were in the range of 84.3-108.5%, and the relative standard deviations based on the peak areas for six replicate analyses of beverages spiked with 10, 50 and 100 ng mL-1 of each biogenic amine were lower than 7.9%. This method has also been successfully applied to analyze the real samples at three different spiked concentrations, and excellent results have been obtained.

Complete Biodegradation of Diclofenac by New Bacterial Strains: Postulated Pathways and Degrading Enzymes

The accumulation of xenobiotic compounds in different environments interrupts the natural ecosystem and induces high toxicity in non-target organisms. Diclofenac is one of the commonly used pharmaceutical drugs that persist in the environment due to its low natural degradation rate and high toxicity. Therefore, this study aimed to isolate potential diclofenac-degrading bacteria, detect the intermediate metabolites formed, and determine the enzyme involved in the degradation process. Four bacterial isolates were selected based on their ability to utilize a high concentration of diclofenac (40 mg/L) as the sole carbon source. The growth conditions for diclofenac degradation were optimized, and bacteria were identified as Pseudomonas aeruginosa (S1), Alcaligenes aquatilis (S2), Achromobacter spanius (S11), and Achromobacter piechaudii (S18). The highest percentage of degradation was recorded (97.79 ± 0.84) after six days of incubation for A. spanius S11, as analyzed by HPLC. To detect and identify biodegradation metabolites, the GC-MS technique was conducted for the most efficient bacterial strains. In all tested isolates, the initial hydroxylation of diclofenac was detected. The cleavage step of the NH bridge between the aromatic rings and the subsequent cleavage of the ring adjacent to or in between the two hydroxyl groups of polyhydroxylated derivatives might be a key step that enables the complete biodegradation of diclofenac by A. piechaudii S18, as well as P. aeruginosa S1. Additionally, the laccase, peroxidase, and dioxygenase enzyme activities of the two Achromobacter strains, as well as P. aeruginosa S1, were tested in the presence and absence of diclofenac. The obtained results from this work are expected to be a useful reference for the development of effective detoxification bioprocesses utilizing bacterial cells as biocatalysts. The complete removal of pharmaceuticals from polluted water will stimulate water reuse, meeting the growing worldwide demand for clean and safe freshwater.

Ionic liquid-based dispersive liquid-liquid microextraction followed by magnetic solid-phase extraction for determination of quinolones

An ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) combined with magnetic solid-phase extraction (MSPE) was developed for extraction of quinolones (quinolones) from honey and milk prior to high-performance liquid chromatography (HPLC) analysis. 1-Butyl-3-methylimidazolium hexafluorophosphate was used as the extraction solvent and an effective adsorbent based on chitosan modified magnetic core-shell functionalized multi-walled carbon nanotube (MWCNTs-Fe₃O₄@SiO₂-CS) nanoparticles was used to assist IL to adsorb quinolone residues in honey and milk samples. Extraction conditions were optimized through one-factor-at-a-time and response surface methodology using a Box-Behnken design. Under optimum conditions satisfactory linearity (R² > 0.999) and high sensitivity (method limits of quantification were 4-8 μg kg^-1 or μg L^-1 in honey or milk samples) was achieved. The recoveries of quinolones in honey and milk ranged from 81.2 to 109%. Based on this study, the proposed method was employed for the determination of antibiotic residues in honey and milk samples.

Novel aqueous biphasic system based on ionic liquid for the simultaneous extraction of seven active pharmaceutical ingredients in aquatic environment

Nonsteroidal anti-inflammatory drugs and antibiotics are classes of active pharmaceutical ingredients (APIs), which are continuously contaminating the ecosystem through various anthropogenic activities. Because of their pseudo-persistence in the aquatic environment and their potentially chronic effects on aquatic life, it is important to closely monitor their concentrations in the aquatic environment using a sensitive analytical method. Sustainable aqueous biphasic systems (ABSs) composed of ionic liquids and biodegradable organic salt (sodium malate) were proposed. The phase diagrams of the systems were firstly determined, and [N₄₄₄₄]Cl-based ABS was selected for the simultaneous extraction and preconcentration of seven APIs. With the developed ABS, extraction efficiencies of APIs close to 100% were obtained. For the developed method, limits of detection (LODs) of 45, 65, 76, 14, 60, 48, and 51 ng L^-1 were obtained for indomethacin, ibuprofen, diclofenac, naproxen, ketoprofen, flurbiprofen, and chloramphenicol, respectively, providing from 1216- to 1238-fold improvement as compared with the analysis without preconcentration. From an economic and environmental point of view, we can predict the prospects and competitive position of the method developed.

Room Temperature Ionic Liquids-Based Electrochemical Sensors: An Overview on Paracetamol Detection

Paracetamol (PAR) is an effective antipyretic and analgesic drug utilized worldwide, safer at therapeutic levels but over-dosing and the chronic usage of PAR results in accumulation of toxic metabolites, which leads to kidney and liver damages. Hence, a simple, rapid, cost-effective, and sensitive analytical technique is needed for the accurate determination of PAR in pharmaceutical and biological samples. Though numerous techniques have been reported for PAR detection, electrochemical methods are being receiving more interest due to their advantages. Moreover, in the past few decades, room temperature ionic liquids (RTILs) have been utilized in electrochemical sensors due to their attractive properties. In this present review, authors gathered research findings available for the determination of PAR using RTIL-based electrochemical sensors and discussed. The advantages and limitations in these systems as well as the future research directions are summarized.

The Influence of Ionic Liquids on the Effectiveness of Analytical Methods Used in the Monitoring of Human and Veterinary Pharmaceuticals in Biological and Environmental Samples-Trends and Perspectives

Recent years have seen the increased utilization of ionic liquids (ILs) in the development and optimization of analytical methods. Their unique and eco-friendly properties and the ability to modify their structure allows them to be useful both at the sample preparation stage and at the separation stage of the analytes. The use of ILs for the analysis of pharmaceuticals seems particularly interesting because of their systematic delivery to the environment. Nowadays, they are commonly detected in many countries at very low concentration levels. However, due to their specific physiological activity, pharmaceuticals are responsible for bioaccumulation and toxic effects in aquatic and terrestrial ecosystems as well as possibly upsetting the body's equilibrium, leading to the dangerous phenomenon of drug resistance. This review will provide a comprehensive summary of the use of ILs in various sample preparation procedures and separation methods for the determination of pharmaceuticals in environmental and biological matrices based on liquid-based chromatography (LC, SFC, TLC), gas chromatography (GC) and electromigration techniques (e.g., capillary electrophoresis (CE)). Moreover, the advantages and disadvantages of ILs, which can appear during extraction and separation, will be presented and attention will be given to the criteria to be followed during the selection of ILs for specific applications.

Ionic liquid-based ultrasound-assisted emulsification microextraction for the determination of ranitidine in water samples and pharmaceutical preparations

A new extraction method is proposed for the isolation of the histamine H₂ receptor antagonist ranitidine (RNT) from aqueous samples.

An Ionic Liquid-based Microextraction Method for Ultra-High Preconcentration of Paraquat Traces in Water Samples Prior to HPLC Determination

An ionic liquid (IL)-based microextraction method was developed for the preconcentration of paraquat traces in water samples prior to HPLC determination. On the basis of the relationship between the aqueous solubility and the extractability of known ILs, 1-ethyl-3-methylimidazolium bis(nonafluorobutanesulfonyl)amide ([EMIm][NNf₂]) was selected as the extractant for paraquat. The distribution ratio of paraquat dication in the [EMIm][NNf₂]/water biphasic system was theoretically estimated to be nearly 10⁸ at its maximum level, indicating that [EMIm][NNf₂] was suitable for the ultra-high preconcentration (a maximum of 10⁶-fold concentration) of paraquat with a quantitative recovery (more than 99%). The extraction procedure could be performed easily and quickly following the in situ solvent formation microextraction technique, and the paraquat traces in the IL phase could be determined by hydrophilic interaction chromatography with good detection limits and linearity ranges (0.16 and 1 - 50 ng mL^-1 for paraquat, respectively). The combined method was successfully applied to four real environmental water samples spiked with paraquat and its analog, diquat at 5.0 ng mL^-1.

Tolfenamic Acid

Tolfenamic acid (TA) is a nonsteroidal antiinflammatory drug and belongs to the group of fenamates. It is used as a potent pain reliever in the treatment of acute migraine attacks, and disorders like dysmenorrhea, rheumatoid, and osteoarthritis. TA has shown excellent in vitro antibacterial activity against certain ATCC strains of bacteria when complexed with bismuth(III). It has also been reported to block pathological processes associated with Alzheimer's disease. In the recent past, TA has also been used as a novel anticancer agent for the treatment of various cancers. In view of the clinical importance of TA, a comprehensive review of the physical and pharmaceutical properties and details of the various analytical methods used for the assay of the drug in pharmaceutical and biological systems has been made. The methods reviewed include identification tests and titrimetric, spectrophotometric, chromatographic, electrochemical, thermal, microscopic, enzymatic, and solid-state techniques. Along with the analytical profile, the stability and degradation of TA, its pharmacology and pharmacokinetics, dosage forms and dose, adverse effects and toxicity, and interactions have been discussed.

Photo-Fenton degradation of the pharmaceuticals ciprofloxacin and fluoxetine after anaerobic pre-treatment of hospital effluent

This work evaluated the photo-Fenton degradation of two pharmaceuticals extensively used in human medicine, ciprofloxacin (CIP), and fluoxetine (FLU) when present in an anaerobic pre-treated hospital effluent (HE) at low concentration (100 μg L^-1). Operational parameters such as concentration of hydrogen peroxide, iron, and initial pH as well as the effect of iron citrate complex were evaluated considering the degradation of the pharmaceuticals. Iron citrate complex (Fecit) influenced significantly FLU degradation at pH 4.5 achieving 80 % after 20 min, while with iron nitrate only 36 % degradation was obtained after the same time. However, only a slight effect was observed on CIP degradation, achieving 86 % with Fecit and 75 % with Fe(NO₃)₃, after 20 min. Samples of HE used in this work were previously treated in an anaerobic reactor followed by sand filtration; however, the presence of pharmaceuticals was detected. Degradation of both FLU and CIP was significantly hindered when present in HE, due to the relatively high content of organic (39.6 mg L^-1) and inorganic (12.5 mg L^-1) carbon, which may have consumed ^·OH in side reactions. However, the iron cycle reduction was not affected by the matrix in the presence of citrate. Despite the recalcitrance of the matrix (no total organic carbon removal), it was possible to achieve over 50 % degradation of both pharmaceuticals after 90 min.

Ultrasound in Combination with Ionic Liquids: Studied Applications and Perspectives

Ionic liquids (ILs) as reaction media, and sonochemistry (US) as activation method, represent separately unconventional approaches to reaction chemistry that, in many cases, generate improvements in yield, rate and selectivity compared to traditional chemistry, or even induce a change in the mechanisms or expected products. Recently, these two technologies have been combined in a range of different applications, demonstrating very significant and occasionally surprising synergetic effects. In this book chapter, the advantages and limitations of the IL/US combination in different chemical applications are critically reviewed in order to understand how, and in which respects, it could become an essential tool of sustainable chemistry in the future. Fundamental aspects and practical considerations of the combination are discussed to better control and demonstrate the brought synergetic effects.

Validation of a UV Spectrometric Method for the Assay of Tolfenamic Acid in Organic Solvents

The present study has been carried out to validate a UV spectrometric method for the assay of tolfenamic acid (TA) in organic solvents. TA is insoluble in water; therefore, a total of thirteen commonly used organic solvents have been selected in which the drug is soluble. Fresh stock solutions of TA in each solvent in a concentration of 1 × 10⁻⁴M (2.62 mg%) were prepared for the assay. The method has been validated according to the guideline of International Conference on Harmonization and parameters like linearity, range, accuracy, precision, sensitivity, and robustness have been studied. Although the method was found to be efficient for the determination of TA in all solvents on the basis of statistical data 1-octanol, followed by ethanol and methanol, was found to be comparatively better than the other studied solvents. No change in the stock solution stability of TA has been observed in each solvent for 24 hours stored either at room (25 ± 1°C) or at refrigerated temperature (2–8°C). A shift in the absorption maxima has been observed for TA in various solvents indicating drug-solvent interactions. The studied method is simple, rapid, economical, accurate, and precise for the assay of TA in different organic solvents.

Determination of selected cardiovascular active compounds in environmental aquatic samples--Methods and results, a review of global publications from the last 10 years

In recent years cardiovascular diseases were the second most common cause of death worldwide. Therefore, the consumption of cardiovascular drugs is high, which might result in an increase of them in the environment. The major source of aquatic environmental contamination is still effluents of wastewater treatment plants (WWTPs). Unfortunately removal of cardiovascular active compounds and/or their metabolites in WWTP is still unsatisfactory. Among microbial and abiotic degradation of these compounds during wastewater processes, photolysis and photodegradation of cardiovascular drugs also play an important role. New formed compounds may be more toxic or retain the properties of parent compounds. Thus the main goal of this paper was to provide a detailed and comprehensive review of used analytical methods, coupled to liquid chromatography-tandem mass spectrometry, to determine the presence of cardiovascular compounds in surface waters as well as WTTPs effluents and influents. Exhaustive preparation for mass spectrometry detection and quantitation including samples pre-treatment, and the common problem of the matrix effect are thoroughly explored in this paper. Additionally, the article provides some hints in respect of recently noted problematic issue related to the availability of specific standards for the analysis of drug's metabolites. Furthermore, information concerning the metabolism of cardiovascular active compounds including differences in metabolism within enantiomers is described. This article also touches on the problems associated with environmental risk assessment due to the presence of cardiovasculars in the environment. The paper also tries to explain differences in concentrations among cardiovascular compounds between countries worldwide.

Multi-residue method for determination of 58 pesticides, pharmaceuticals and personal care products in water using solvent demulsification dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry

A rapid and efficient sample pretreatment using solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was studied for the extraction of 58 pharmaceuticals and personal care products (PPCPs) and pesticides from water samples. Type and volume of extraction and disperser solvents, pH, salt addition, amount of salt and type of demulsification solvent were evaluated. Limits of quantification (LOQ) in the range from 0.0125 to 1.25 µg L(-1) were reached, and linearity was in the range from the LOQ of each compound to 25 μg L(-1). Recoveries ranged from 60% to 120% for 84% of the compounds, with relative standard deviations lower than 29%. The proposed method demonstrated, for the first time, that sample preparation by SD-DLLME with determination by LC-MS/MS can be successfully used for the simultaneous extraction of 32 pesticides and 26 PPCPs from water samples. The entire procedure, including the extraction of 58 organic compounds from the aqueous sample solution and the breaking up of the emulsion after extraction with water, rather than with an organic solvent, was environmentally friendly. In addition, this technique was less expensive and faster than traditional techniques. Finally, the analytical method under study was successfully applied to the analysis of all 58 pesticides and PPCPs in surface water samples.

Dispersive suspended-solidified floating organic droplet microextraction of nonsteroidal anti-inflammatory drugs: comparison of suspended droplet-based and dispersive-based liquid-phase microextraction methods

A dispersive suspended-solidified floating organic droplet microextraction method was developed for determination of some nonsteroidal anti-inflammatory drugs in human plasma and urine samples.