Use of magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction to extract fungicides from environmental waters with the aid of experimental design methodology

Recent Advances in Dispersive Liquid-Liquid Microextraction for Pharmaceutical Analysis

Sample clean-up and pre-concentration are critical components of pharmaceutical analysis. The dispersive liquid-liquid microextraction (DLLME) technique is widely recognized as the most effective approach for enhancing overall detection sensitivity. While various DLLME modes have been advanced in pharmaceutical analysis, there need to be more discussions on pre-concentration techniques specifically developed for this field. This review presents a comprehensive overview of the different DLLME modes used in pharmaceutical analysis from 2017 to May 2023. The review covers the principles of DLLME, the factors affecting microextraction, the selected applications of different DLLME modes, and their advantages and disadvantages. Additionally, it focuses on multi-extraction strategies employed for pharmaceutical analysis.

Pyrethroid residues in Indonesian river Citarum: A simple analytical method applied for an ecological and human health risk assessment

Pyrethroid residues in the Citarum River, Indonesia, was first investigated based on their occurrences, water assimilative capacity, and risk assessment. In this paper, first, a relatively simple and efficient method was built and validated for analysis of seven pyrethroids in river water matrix: bifenthrin, fenpropathrin, permethrin, β-cyfluthrin, cypermethrin, fenvalerate, and deltamethrin. Next, the validated method was used to analyze pyrethroids in the Citarum River. Three pyrethroids, β-cyfluthrin, cypermethrin, and deltamethrin, were detected in some sampling points with concentration up to 0.01 mg/L. Water assimilative capacity evaluation shows that β-cyfluthrin and deltamethrin pollution exceed the Citarum river water capacity. However, due to hydrophobicity properties of pyrethroids, removal through binding to sediments are expected. Ecotoxicity risk assessment shows that β-cyfluthrin, cypermethrin and deltamethrin pose risks to the aquatic organisms in the Citarum River and its tributaries through bioaccumulation in food chain. Based on bioconcentration factors of the detected pyrethroids, β-cyfluthrin poses the highest adverse effect to humans while cypermethrin is the safest. Human risk assessment based on hazard index suggests that acute non-carcinogenic risk associated to consuming fish from the study location polluted with β-cyfluthrin, cypermethrin and deltamethrin is unlikely. However, hazard quotient shows that chronic non-carcinogenic risk associated to consuming fish from the study location polluted with β-cyfluthrin is likely. However, since the risk assessment was performed separately for each pyrethroid, further assessment on the impact of mixture pyrethroid to aquatic organisms and humans should be performed to explore the real impact of pyrethroids to the river system.

Quality assessment of African herbal medicine: A systematic review and the way forward

BACKGROUND

In Africa, herbalism supplements allopathic medicine's efforts to ensure Universal Health Coverage attainment. This review was conducted to identify and to summarise current literature on methodological approaches used for quality control of herbal medicines in Africa, to evaluate the gaps associated with existing strategies within context of best practices, and make recommendations for future improvements.

METHODS

A systematic search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were screened and assessed for eligibility.

RESULTS

118 articles were included into the study. There was a high preference for impurity profiling tests (77%) indicating the prioritization for tests that guarantee safety despite the limited analytical resources available. Other classes of tests reported included identification tests (29%), physicochemical tests (18%), and content assays (12%). Although standard methods exist in preparing samples for impurity tests, different techniques were observed in different studies, and this could lead to differences in analytical outcomes. Content assays focused on single marker assessments, which may be inadequate to comprehensively assess the quality of products.

CONCLUSION

This review provides knowledge of existing strengths and challenges for herbal medicine quality assessments in Africa. For future it is recommended to implement more studies on contaminants (e.g. mycotoxins) and pharmaceutical adulterants. The use of chemometrics to develop analytical methods should be promoted. Also, stakeholders in the medicine quality industry in Africa need to effectively collaborate to establish a well co-ordinated and harmonized system to provide a sustainable framework for the GACP and GMP guided production and quality assurance of herbal medicines.

Ionic Liquid-Assisted DLLME and SPME for the Determination of Contaminants in Food Samples

Developing effective and green methods for food analysis and separation has become an urgent issue regarding the ever-increasing concern of food quality and safety. Ionic liquids (ILs) are a new chemical medium and soft functional material developed under the framework of green chemistry and possess many unique properties, such as low melting points, low-to-negligible vapor pressures, excellent solubility, structural designability and high thermal stability. Combining ILs with extraction techniques not only takes advantage of ILs but also overcomes the disadvantages of traditional extraction methods. This subject has attracted intensive research efforts recently. Here, we present a brief review of the current research status and latest developments regarding the application of IL-assisted microextraction, including dispersive liquid–liquid microextraction (DLLME) and solid-phase microextraction (SPME), in food analysis and separation. The practical applications of ILs in determining toxic and harmful substances in food specimens with quite different natures are summarized and discussed. The critical function of ILs and the advantages of IL-based microextraction techniques over conventional extraction techniques are discussed in detail. Additionally, the recovery of ILs using different approaches is also presented to comply with green analytical chemistry requirements.

Development of effervescence-assisted switchable-polarity solvent homogeneous liquid-phase microextraction for the determination of permethrin and deltamethrin in water samples prior to GC-FID

An effervescent tablet-assisted switchable polarity solvent-based homogeneous liquid-phase microextraction (ETA-SPS-HLPME) combined with gas chromatography with flame ionization detection has been conducted for the separation, preconcentration, and detection of permethrin and deltamethrin in the river water specimens. The triethylamine (TEA) was utilized as a switchable polarity solvent in this method. The switching process was carried out by the dissolution of an effervescent tablet including an effervescency agent (sodium carbonate) and a proton donor agent (citric acid). Changing the pH of the specimen solution enhanced the conversion of TEA into protonated triethylamine carbonate (P-TEA-C) through the tablet that generated carbon dioxide (CO₂ ) bubbles in situ. Finally, the addition of sodium hydroxide changed the ionization state of TEA and separated two phases. Influential factors in extraction were investigated. According to optimal situations, the limits of detection (LOD) and the limits of quantification (LOQ) were obtained 0.16 and 0.5 μgL^-1 for permethrin and 0.03 and 0.1 μgL^-1 for deltamethrin respectively. The preconcentration factor (PF) was achieved 194 in river water samples and interday and intraday precision (RSD % n = 5) was <5%. The extraction recovery was obtained in the range of 93.0-97% for permethrin and deltamethrin in water samples.

In-syringe ionic liquid-dispersive liquid-liquid microextraction coupled with HPLC for the determination of trans,trans-muconic acid in human urine sample

trans,trans-Muconic acid has been widely used as a biomarker in biological monitoring of benzene-exposed workers during routine occupational health services. In the present study, a novel microextraction technique, in-syringe ionic liquid-dispersive liquid-liquid microextraction, was implemented for preconcentration of trans,trans-muconic acid followed by analytical determination by high-performance liquid chromatography with ultraviolet detection. Moreover, the important variables affecting the performance of applied microextraction technique including needle diameter, volume of the spiked sample, volume of the ionic liquid, salt addition, rotation speed of centrifugation, centrifuge time, and ultrasonic time were optimized by experimental design. A good linear relationship was observed at the range of 0.032-10 μg/mL between the peak area and the concentration levels (R²  = 0.9997). The limit of detection and extraction recovery for trans,trans-muconic acid were 0.011 μg/mL and >96.2%, respectively. This method provided easy and rapid analysis of low amounts of trans,trans-muconic acid in human urine with simple equipment.

Determination of Polybrominated Diphenyl Ethers in Water Samples Using Effervescent-Assisted Dispersive Liquid-Liquid Icroextraction with Solidification of the Aqueous Phase

An effective and sensitive method is necessary for the determination of polybrominated diphenyl ethers (PBDEs) pollutants in water. In this study, effervescent-assisted dispersive liquid-liquid microextraction with solidification of the aqueous phase (EA-DLLME-SAP), followed by Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS) quantitative analysis, was established for the preconcentration and determination of PBDEs in real environmental water samples. 1,1,2,2-Tetrachloroethane was used as the extractant and directly dispersed into the water phase of the aqueous samples with the aid of a large number of carbon dioxide bubbles generated via the acid-base reaction of acetic acid and sodium bicarbonate, which did not require the use of a dispersant during the extraction process. The key factors affecting the extraction recovery were optimized, and an internal standard was used for quantitative analysis, which gave good linearity ranges of 1-100 ng·L^-1 (BDEs 28, 47, 99, and 100), 2-200 ng·L^-1 (BDEs 153, 154, and 183) and 5-500 ng·L^-1 (BDE 209) with limits of quantification in the range of 1.0-5.0 ng·L^-1. The accuracy was verified with relative standard deviations < 8.5% observed in tap, lake, river and reservoir water samples with relative recoveries ranging from 67.2 to 102.6%. The presented method contributes to the determination of PBDEs in environmental water samples.

An accurate and sensitive effervescence-assisted liquid phase microextraction method for the determination of cobalt after a Schiff base complexation by slotted quartz tube-flame atomic absorption spectrophotometry in urine samples

In this study, an accurate analytical method development for cobalt determination in urine samples was described. The method is based on the mass transfer of the target analytes to the organic phase from the aqueous phase by the dispersing extractant throughout the solution with the aid of CO₂ bubbles prior to sample measurement by using a slotted quartz tube flame atomic absorption spectrophotometer. An extractor (1-decanol) dropped effervescent tablet (anhydrous sodium carbonate and sodium dihydrogen phosphate dihydrate mixture) was used in order to separate/preconcentrate cobalt after complexation of cobalt ions in aqueous solution with the Schiff base ligand. The parameters affecting the extraction output such as complexing conditions (pH, ligand concentration, and volume) and extraction conditions (extraction solvent type and volume, extraction temperature, and heating duration, NaOH volume and mixing period) were optimized to lower the detection limit. The limit of detection and quantification values under optimized experimental and instrumental conditions were determined as 3.7 μg L^-1 and 12 μg L^-1, respectively with high linearity with respect to the dynamic range between 15 and 300 μg L^-1. The enhancement factor obtained with the developed method was calculated as 83 fold. The pretreatment process was applied to urine samples in order to test the convenience of the developed method in urine samples for the determination of cobalt at low levels. The high percentage recovery results of 96-97% for four different concentrations of spiked urine samples indicated the proposed method's sufficient sensitivity for analyte determination in such a complex matrix.

Effervescence-Assisted Microextraction-One Decade of Developments

Dispersive microextraction techniques are key in the analytical sample treatment context as they combine a favored thermodynamics and kinetics isolation of the target analytes from the sample matrix. The dispersion of the extractant in the form of tiny particles or drops, depending on the technique, into the sample enlarges the contact surface area between phases, thus enhancing the mass transference. This dispersion can be achieved by applying external energy sources, the use of chemicals, or the combination of both strategies. Effervescence-assisted microextraction emerged in 2011 as a new alternative in this context. The technique uses in situ-generated carbon dioxide as the disperser, and it has been successfully applied in the solid-phase and liquid-phase microextraction fields. This minireview explains the main fundamentals of the technique, its potential and the main developments reported.

Effervescence-assisted spiral hollow-fibre liquid-phase microextraction of trihalomethanes, halonitromethanes, haloacetonitriles, and haloketones in drinking water

A new analytical method was optimized to determine 18 disinfection by-products (DBPs) in drinking water, including four different chemical groups. For this purpose, spiral-shaped hollow-fibre liquid phase microextraction with 1-octanol as the acceptor solvent assisted by effervescence was applied using a homemade supporting device that was specifically designed for this application. The device was printed in a 3D printer and allows for an increased fibre surface even with a low sample volume, which significantly facilitates the extraction. The samples were analysed by gas chromatography coupled to both an electron capture detector and a mass spectrometer for the quantification and unequivocal identification of the analytes, respectively. Effervescence was generated using citric acid and bicarbonate at a molar ratio 1:2, which significantly improves the extraction efficiency and reduces mechanical operations, since stirring and modifiers are not required. The results showed enrichment factors ranging from 13.1 to 140.1. Satisfactory recoveries (80-113 %) were obtained, with relative standard deviations from 3 to 15 % and good linearity. The detection limits (ng L^-1) ranged from 10 to 35 (trihalomethanes), 12 to 220 (halonitromethanes), 17 to 79 (haloacetonitriles) and 10 to 16 (haloketones). The applicability of the method was assessed in 6 local water distribution systems.

Role of Ionic Liquids in Composites in Analytical Sample Preparation

Ionic liquids (ILs) are a group of non-conventional salts with melting points below 100 °C. Apart from their negligible vapor pressure at room temperature, high thermal stability, and impressive solvation properties, ILs are characterized by their tunability. Given such nearly infinite combinations of cations and anions, and the easy modification of their structures, ILs with specific properties can be synthesized. These characteristics have attracted attention regarding their use as extraction phases in analytical sample preparation methods, particularly in liquid-phase extraction methods. Given the liquid nature of most common ILs, their incorporation in analytical sample preparation methods using solid sorbents requires the preparation of solid derivatives, such as polymeric ILs, or the combination of ILs with other materials to prepare solid IL-based composites. In this sense, many solid composites based on ILs have been prepared with improved features, including magnetic particles, carbonaceous materials, polymers, silica materials, and metal-organic frameworks, as additional materials forming the composites. This review aims to give an overview on the preparation and applications of IL-based composites in analytical sample preparation in the period 2017–2020, paying attention to the role of the IL material in those composites to understand the effect of the individual components in the sorbent.

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.

Magnetic Particles-Based Analytical Platforms for Food Safety Monitoring

Magnetic nanoparticles (MNPs) have attracted growing interest as versatile materials for the development of analytical detection and separation platforms for food safety monitoring. This review discusses recent advances in the synthesis, functionalization and applications of MNPs in bioanalysis. A special emphasis is given to the use of MNPs as an immobilization support for biomolecules and as a target capture and pre-concentration to increase selectivity and sensitivity of analytical platforms for the monitoring of food contaminants. General principles and examples of MNP-based platforms for separation, amplification and detection of analytes of interest in food, including organic and inorganic constituents are discussed.

Novel functionalized magnetic ionic liquid green separation technology coupled with high performance liquid chromatography: A rapid approach for determination of estrogens in milk and cosmetics

Several magnetic ionic liquids (MILs), [P_6,6,6,14⁺][FeCl₄^-], [P_6,6,6,14⁺]₂[MnCl₄^2-], [P_6,6,6,14⁺]₂[CoCl₄^2-] and [P_6,6,6,14⁺]₂[NiCl₄^2-] were synthesized and applied for the extraction of six estrogens (estrone, estradiol, 17-α-hydroxyprogesterone, chloromadinone 17-acetate, megestrol 17-acetate and medroxyprogesterone 17-acetate) in dispersive liquid-liquid microextraction (DLLME). The [CoCl₄^2-]-based MIL was selected as extraction solvent for the separation and concentration of estrogens from milk and cosmetics due to its visual recognition, no sign of hydrolysis, solution acquisition easier and the highest extraction capacity. In addition, the [CoCl₄^2-]-based MIL with low UV absorbance allows direct analysis of the extraction solvent by HPLC-UV. The influence of the mass of MIL, extraction time, salt concentration, and the pH of the sample solution was investigated to obtain optimized extraction efficiency. Besides, extraction conditions including salt concentration, mass of MIL and extraction time were further optimized by the Box-Behnken design through the response surface method. Under optimized conditions, the limits of detection (LODs) of all estrogens were ranged from 5 ng mL^-1 to 15 ng mL^-1. The recoveries ranging from 98.5% to 109.3% in milk and from 96.3% to 111.4% in cosmetics were also studied, respectively. Furthermore, the proposed method were statistically compared with the reported conventional IL-DLLME method and the National standard methods of food safety and cosmetics. The experimental results showed that the functionalized MIL could successfully applied for extraction, separation and pretreatment of estrogens in milk and cosmetics.

Preparation of a magnetic graphene/polydopamine nanocomposite for magnetic dispersive solid-phase extraction of benzoylurea insecticides in environmental water samples

A magnetic graphene/polydopamine (MG/PDA) nanocomposite has been prepared and used as sorbent for magnetic dispersive solid-phase extraction (MDSPE) of four benzoylurea insecticides in environmental water samples. The obtained nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometry, powder X-ray diffraction, fourier transform infrared spectroscopy, surface area and porosity analysis and thermogravimetric analysis. To investigate the adsorption performance of MG/PDA for target analytes, various parameters affecting the MG/PDA-based MDSPE procedure were optimized. Under the optimal conditions, the established method exhibits good linearity (R2 ≥ 0.9988) in the concentration range 2.5-500 µg L-1. A low limit of detection (0.75 µg L-1, signal/noise = 3:1), a low limit of quantification (2.50 µg L-1, signal/noise = 10:1), and good precision (intraday relative standard deviation ≤3.6%, interday relative standard deviation ≤4.5%) are also achieved. Finally, the simple, fast, and sensitive sample preparation technique was successfully used to determine benzoylurea insecticides in environmental water samples.

Evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets for the determination of triazole fungicides in water samples by high-performance liquid chromatography

A simple, rapid, and effective analytical procedure for determining three triazole fungicides (myclobutanil, epoxiconazole, and tebuconazole) in water samples is developed by high-performance liquid chromatography-diode array detection after evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets. The extraction procedure involves the sequential addition of the extraction solvent 1-dodecanol (low density), volatile solvent dichloromethane (high density), and calcium oxide to the aqueous sample (the latter reacting exothermically). The CaO reaction can promote the volatilization of the dichloromethane which disperses the 1-dodecanol as fine droplets in the aqueous sample due to the bubbles generated. Therefore, a dispersive solvent is not required. Then, the floating 1-dodecanol is solidified using an ice bath for easy separation from the sample. The variables (the volumes of extraction and volatile solvents, amounts of calcium oxide and sodium chloride, pH values, and extraction time) in the extraction procedure are further optimized. Under optimized conditions, the linearity ranges are 0.05-5 μg mL^-1 with correlation coefficients greater than 0.99. The limits of detection and quantification are 0.0051-0.0090 μg mL^-1 and 0.0169-0.0299 μg mL^-1, respectively. The recoveries of myclobutanil, epoxiconazole, and tebuconazole in tap, reservoir, and river water range between 77.6% and 104.4% with relative standard deviations ranging from 0.6% to 7.8%. Hence, the method was reliable for analysis of myclobutanil, epoxiconazole, and tebuconazole in water samples.

Magnetic effervescent tablet-assisted ionic liquid-based dispersive liquid-liquid microextraction of polybrominated diphenyl ethers in liquid matrix samples

Herein, a novel method, magnetic effervescent tablet-assisted ionic liquid-based dispersive liquid-liquid microextraction (META-IL-DLLME), was pioneered for extraction and preconcentration of polybrominated diphenyl ethers (PBDEs) in liquid matrix samples. In this proposed method, a magnetic effervescent tablet, containing CO₂ sources, ionic liquids and Fe₃S₄ magnetic nanoparticles (MNPs), combines extractant dispersion and magnetic recovery into one-step. Fe₃S₄ was synthesized, characterized and applied it for the first time to the newly developed method, and its extraction recoveries (ERs) for PBDEs were 20.8-32.0% higher than those of conventional Fe₃O₄ MNPs. The increased ERs of Fe₃S₄ resulted from its larger specific surface area and pore size. Some important parameters were rigorously optimized, such as kinds of magnetic nanoparticles, effervescent agents, extraction solvents and their volumes, elution solvents, extraction temperature and salt addition. Under the optimized conditions, the META-IL-DLLME method combined with HPLC-DAD analysis gave the linear ranges of 0.1-0.5-100 µg L^-1 with correlation coefficients of > 0.9990. The ERs ranged from 80.7% to 99.3%, and the limits of detection and quantitation were 0.012-0.078 µg L^-1 and 0.04-0.26 µg L^-1, respectively. The intra- and inter-day precisions, expressed as relative standard deviations (RSD, n = 6), were 1.32-4.83% and 1.99-4.25%, respectively. To evaluate its matrix effect, the relative recoveries of PBDEs from tap and river water, skim and whole milk, pregnant women and women serum samples at three fortification levels (2.0, 5.0 and 20.0 µg L^-1) were in the range of 77.3-106.7%. Overall, the commercial Fe₃O₄ MNPs can only be used for magnetic separation in microextraction procedures, while Fe₃S₄ MNPs gave the higher adsorption and extraction efficiency for organic analytes besides the convenient magnetic separation. Therefore, the results obtained in this study provide a superior alternative for the conventional magnetic separation and adsorbent material. Also, this newly developed method has a great potential in routine monitoring of liquid matrix samples.