Preconcentration of Cinnamic Acid Derivatives in Traditional Chinese Medicines by an Effective Dispersive Liquid-Liquid Microextraction Based on a Hydrophobic Deep Eutectic Solvent.

A dispersive liquid-liquid microextraction based on hydrophobic deep eutectic solvent (hDES) was developed for the extraction and quantification of four cinnamic acid derivatives in traditional Chinese medicines coupled with high-performance liquid chromatography-ultraviolet detection. In this method, a hDES (tetrabutylammonium chloride-hexanoic acid, molar ratio of 1:2) was prepared as the extractant. It only took 15 s to handle multiple samples simultaneously by hand-assisted dispersion. The use of a narrow-bore tube reduced the amount of the hydrophobic extractant with easier recovery. The approach was influenced by several key parameters, including the composition and consumption of the DES, sample phase pH, salt amount, extraction time, and centrifugation time, all of which had been investigated and optimized. Moreover, the formation of the DES was characterized by Fourier-transform infrared spectroscopy and differential scanning calorimetry. Under the optimal conditions, enrichment factors of the target analytes ranged from 135 to 220. Satisfactory linearities (r ≥ 0.9977), detection limits (0.2-0.4 ng/mL), precision (<8.5%), and accuracy (recoveries: 90.0%-104.6%) were obtained. The method has been successfully applied to the simultaneous extraction and preconcentration of four cinnamic acid derivatives in Chinese medicinal samples with rapidness, high efficiency, and convenience.

Effervescence tablets based on magnetic ionic liquids as simple microdevices for the in situ dispersive liquid-liquid microextraction of urinary biomarkers.

BACKGROUND: Magnetic ionic liquids (MILs) have been explored in dispersive liquid-liquid microextraction (DLLME). Their usage allows to substitute centrifugation and/or filtration steps by a quick magnetic separation. Besides, effervescence-assisted DLLME is one of the most known options to improve the dispersion of the extractant in the sample, while allowing to avoid the consumption of external energy during dispersion. Despite these interesting features, only one study incorporates MILs containing the tetrachloroferrate anion in effervescence tablets. These MILs are highly viscous and liquid at room temperature, thus compromising the stability of the tablets when used as extraction microdevices in effervescence-assisted DLLME, and only allowing their use in the conventional MIL-DLLME mode. RESULTS: A new class of effervescence tablets containing a Ni(II)-based MIL, that is solid at room temperature, is here proposed. This type of tablets permits their use, for first time, in the in situ DLLME mode, occurring through the transformation of a water-soluble MIL into a water-insoluble MIL microdroplet. This way, the tablet formulation included: the MIL, the metathesis reagent lithium bis[(trifluoromethyl)sulfonyl]imide, NaH2PO4 and K2CO3 as effervescence precursors salts, and Na2SO4 as salting-out and desiccating agent. The method is combined with high-performance liquid-chromatography and both fluorescence and ultraviolet detection, for the determination of monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and benzophenones (BPs), as biomarkers in urine. The method simply involved the addition of the effervescence tablet to the sample, thus taken place simultaneously the effervescence process and the metathesis reaction, without requiring any external energy consumption. The method presented limits of detection down to 10 ng L-1 for OH-PAHs and to 0.60 µg L-1 for BPs, inter-day relative standard deviations lower than 17 %, and average relative recoveries of 94 % in urine. The determined OH-PAHs contents in urine were between 0.40 and 16 µg L-1, and between 17.8 and 334 µg L-1 for BPs. SIGNIFICANCE: We have developed the first MIL-based effervescence tablets that are completely solid, thus improving the stability and robustness of these microdevices with respect to previously reported tablets involving MILs, while permitting to perform into the in situ DLLME mode (thus gaining in extraction efficiency). This approach including the MIL-based effervescence tablets constitutes an alternative on-site platform for the analysis of urine, as satisfactory precision, accuracy, and sensitivity are achieved despite not involving any external energy input within the analytical sample preparation setup. This method also constitutes the first application of MIL-based effervescence tablets for bioanalysis.

A green procedure for the determination of bioavailable forms of aluminum in natural waters by electrothermal atomic absorption spectroscopy combined with microextraction technique.

Aluminum is a prevalent element in nature, but bioavailable forms of aluminum are toxic to plants, animals, and humans. The present study is dedicated to the development of an ecologically friendly, fast, simple, reliable, sensitive, and accurate improved procedure for the determination of subtrace concentrations of bioavailable forms of aluminum in natural waters. The procedure includes the separation and pre-concentration of bioavailable forms of aluminum using vortex-assisted liquid-liquid microextraction (VALLME) of ionic associates with salicylaldehyde 4-picolinhydrazone (SAPH) and sodium dodecyl sulfate (DDSNa) by isoamylacetate (200 µl) and direct electrothermal atomic absorption spectroscopy (ET AAS). The SAPH reagent interacts only with water-soluble forms of aluminum. SAPH is used for the pre-concentration of bioavailable forms of aluminum as well as a chemical modifier; it increases the absorbance and the precision of the analytical signal of aluminum. The calibration curve shows the linear dependence in the range of 0.05-86 µg⋅L-1 of the aluminum concentration (R2 = 0.992), with the limit of detection at 0.015 µg⋅L-1 and the limit of quantification at 0.05 µg⋅L-1. The accuracy of the proposed procedure for bioavailable forms of aluminum determination was verified on model solutions and against a reference method on natural samples of river and lake waters (RSD 3.2-5.2%, recovery 97.1-103.4%).

Alcohol-based hydrophobic deep eutectic solvents and ultrasound-assisted liquid phase microextraction followed by GC-MS for the extraction and analysis of organophosphorus pesticides in the blood of farmers.

Organophosphorus pesticides (OPPs) are a group of pesticides that are most widely used in the agricultural sector, and farmers are exposed to these chemicals more than other members of society. In this work, an environmentally friendly, simple, and safe ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) method using alcohol-based hydrophobic deep eutectic solvents (HDESs) followed by gas chromatography-mass spectroscopy (GC-MS) was developed for the extraction and determination of OPPs in the blood of farmers studied in Ravansar cohort. DESs synthesized from thymol as hydrogen bond donor (HBD) and aliphatic alcohols as hydrogen bond acceptor (HBA) have been used as extractants. Under optimal experimental conditions, the reproducibility of the method based on 7 replicate measurements of 10 µg L-1 of OPPs in blood samples was in the range of 1.4-3.8%. The method showed a linearity in the range of 0.01-150 µg L-1. The limits of detection and limits of quantification were between 0.003 and 0.02 µg L-1 and 0.01-0.05 µg L-1, respectively. The matrix effect and accuracy of the method were confirmed by spiking different amounts of OPPs in real blood samples and obtaining relative recoveries in the range of 91-112%. The results showed that the concentration of OPPs in the case group was significantly higher than in the control group, which is because the case group was exposed to OPPs during the spraying of agricultural products.

Natural deep eutectic solvent for the simultaneous derivatization and microextraction of isoniazid from human plasma.

BACKGROUND: Personalized medicine is a rapidly revolving field that offers new opportunities for tailoring disease treatment to individual patients. The main idea behind this approach is to carefully select safe and effective medications and treatment plant based on each patient's unique pharmacokinetic profile. Isoniazid is a first-line anti-tuberculosis drug that has interindividual variability in its metabolic processing, leading to significant differences in plasma concentrations among patients receiving equivalent doses. This variability necessitates the creation of individualized treatment regimens as part of personalized medicine to achieve more effective therapy. RESULTS: In this work, a deep eutectic solvent-based liquid-liquid microextraction approach for the separation and determination of isoniazid in human plasma by high-performance liquid chromatography with UV-Vis detection was developed for the first time. A new natural deep eutectic solvent based on thymol as a hydrogen bond donor and 4-methoxybenzaldehyde as a hydrogen bond acceptor was proposed as the extraction solvent. The developed microextraction procedure assumed two simultaneous processes during the mixing of the sample and extraction solvent: the derivatization of the polar analyte in the presence of 4-methoxybenzaldehyde (component of the natural deep eutectic solvent) with the formation of a hydrophobic Schiff base (1); mass transfer of the Schiff base from the sample phase to the extraction solvent phase (2). Under optimal conditions, the limits of detection and quantification were 20 and 60 µg L-1, respectively. The RSD value was <10 %, the extraction recovery was 95 %. SIGNIFICANCE: In this work, the possibility of isoniazid derivatization in the natural deep eutectic solvent phase with the formation of the Schiff base was presented for the first time. The approach provided the separation and preconcentration of polar isoniazid without the use of expensive derivatization agents and solid-phase extraction cartridges. The formation of the Schiff base was confirmed by mass spectrometry.

Supramolecular solvents based on hydrophobic natural deep eutectic solvents and primary amines for preconcentration and determination of enrofloxacin in milk.

In this work, coacervation in primary amines solutions with hydrophobic natural deep eutectic solvents based on terpenoids and carboxylic acids was demonstrated for the first time. A liquid-phase microextraction approach was developed based on supramolecular solvent formation with primary amine acting as amphiphile and hydrophobic deep eutectic solvent making up mixed vesicles and serving as coacervation agent. Such supramolecular solvents could be used to separate wide range of substances from different aqueous media, such as food products, biological liquids and wastewaters. It is important that both hydrophobic and ionic interactions with supramolecular aggregates take place ensuring synergetic effect and better extraction ability, which is significant in separating relatively polar analytes. Different primary amines and deep eutectic solvents were investigated for liquid-phase microextraction of proof-of-concept amphoteric analyte (enrofloxacin, widely used veterinary fluoroquinolone antibiotic) and its determination by high-performance liquid chromatography with fluorescence detection using Shimadzu LC-20 Prominence chromatograph and RF-20A fluorescence detector. It was found that the supramolecular solvent based on 1-nonylamine, formed after addition of a deep eutectic solvent based on menthol and hexanoic acid (molar ratio of 1:1), provided maximum extraction recovery (85 %) and maximum enrichment factor (34). To characterize the extraction system, the composition of the phases was investigated, and cryo-transmission electron microscopy images were obtained. Vesicular aggregates were observed in the supramolecular solvent. The extraction mechanism was proposed in terms of formation of mixed aggregates to capture the analyte. Limit of detection was found to be 7 µg kg-1, while linear range of 20-250 µg kg-1 was established. Relative standard deviation values were lower than 7 %. Relative bias did not exceed 12 %.

Primary alcohol-induced coacervation in alkyl polyglucoside micellar solution for supramolecular solvent-based microextraction and chromatographic determination of phthalates in baby food.

This study reports for the first time the phenomenon of supramolecular solvent formation based on alkyl polyglucoside as an amphiphile and primary alcohol as a coacervation agent. The physical properties (density, kinematic viscosity, phase diagram for ternary system) of the supramolecular solvent were investigated, and a mechanism for its formation was proposed. A green and simple microextraction procedure for preconcentration and determination of phthalates in baby foods packaged in plastic packaging was developed as proof-of-concept example. The microextraction procedure assumed separation of analytes from solid phase sample in micellar solution of decyl glucoside and in situ formation of supramolecular solvent for analytes preconcentration after addition of n-heptanol. The determination of phthalates in obtained extracts was implemented by high-performance liquid chromatography with UV-Vis detection. The limits of detection, calculated from a blank test based on 3σ, were determined to be 10 µg kg-1 for dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, and di-n-octyl phthalate. The developed procedure did not require filtration of sample suspension, and assumed the use of green and biodegradable substances for the supramolecular solvent formation across a wide pH range.

Lab-made automated parallel-dispersive pipette extraction device for the determination of polycyclic aromatic hydrocarbons in distilled beverages (sugarcane spirits) using HPLC-DAD.

This work describes the development of a new automated parallel dispersive tip microextraction method (Au-Pa-DPX) for the determination of eleven polycyclic aromatic hydrocarbons (PAHs) in four samples of Brazilian sugarcane spirit beverages, with separation and detection done by the HPLC-DAD. The results obtained with the Au-Pa-DPX approach were also compared with those obtained via the conventional parallel manual DPX method with the same samples and optimized extraction process. Desorption solvent and cycles of desorption, cleaning and extraction were optimized using response surface methodology and univariate approaches. For the Au-Pa-DPX method, the coefficient of determination (R2) ranged from 0.9948 to 0.9997. The limits of detection and quantification were all 0.303 µg l-1 and 1.00 µg l-1, respectively. Interday and intraday precision ranged from 7.6 % to 31.7 % and 0.40 % to 15.8 %, respectively. For the manual parallel DPX method, the interday and intraday precision ranged from 8.2 % to 38.1 % and 5.40 % to 18.7 %, respectively. The relative recovery values obtained with the proposed method ranged from 53.29 to 124.94 %. The enrichment factors ranged from 15.13 to 22.35. The sum of PAH concentrations in the four samples ranged from undetected to 25.58 µg l-1. These results, when correlated to other methods, highlight the gains in regards to precision obtained with the automated apparatus. Furthermore, when compared to other methods from the literature, it is an interesting green alternative for the determination of these analytes and this sample, with high throughput (4.67 min per sample), low consumption of solvents and samples, generating less waste and reducing health risks to the analyst.

[Rapid determination of nine preservatives in tobacco flavor by three phase-hollow fiber-liquid phase microextraction-high performance liquid chromatography].

Tobacco flavors are extensively utilized in traditional tobacco products, electronic nicotine, heated tobacco products, and snuff. To inhibit fungal growth arising from high moisture content, preservatives such as benzoic acid (BA), sorbic acid (SA), and parabens are often incorporated into tobacco flavors. Nonetheless, consuming preservatives beyond safety thresholds may pose health risks. Therefore, analytical determination of these preservatives is crucial for both quality assurance and consumer protection. For example, BA and SA can induce adverse reactions in susceptible individuals, including asthma, urticaria, metabolic acidosis, and convulsions. Parabens, because of their endocrine activity, are classified as endocrine-disrupting chemicals. Despite extensive research, the concurrent quantification of trace-level hydrophilic (BA and SA) and hydrophobic (methylparaben, ethylparaben, isopropylparaben, propylparaben, butylparaben, isobutylparaben, and benzylparaben) preservatives in tobacco flavors remains challenging. Traditional liquid phase extraction coupled with high performance liquid chromatography (HPLC) often results in high false positive rates and inadequate sensitivity. In contrast, tandem mass spectrometry offers high sensitivity and specificity; however, its widespread application is limited by laborious sample preparation and significant operational costs. Therefore, it is crucial to establish a fast and sensitive sample pretreatment and analysis method for the nine preservatives in tobacco flavors. In this study, a method for the simultaneous determination of the nine preservatives (SA, BA and seven parabens) in tobacco flavor was established based on three phase-hollow fiber-liquid phase microextraction (3P-HF-LPME) technology combined with HPLC. To obtain the optimal pretreatment conditions, extraction solvent type, sample phase pH, acceptor phase pH, sample phase volume, extraction time, and mass fraction of sodium chloride, were examined. Additionally, the HPLC parameters, including UV detection wavelength and mobile phase composition, were refined. The optimal extraction conditions were as follows: dihexyl ether was used as extraction solvent, 15 mL sample solution (pH 4) was used as sample phase, sodium hydroxide aqueous solution (pH 12) was used as acceptor phase, and the extraction was carried out at 800 r/min for 30 min. Chromatographic separation was accomplished using an Agilent Poroshell 120 EC-C18 column (100 mm×3 mm, 2.7 µm) and a mobile phase comprising methanol, 0.02 mol/L ammonium acetate aqueous solution (containing 0.5% acetic acid), and acetonitrile for gradient elution. Under the optimized conditions, the nine target analytes showed good linear relationships in their respective linear ranges, the correlation coefficients (r) were ≥0.9967, limits of detection (LODs) and quantification (LOQs) were 0.02-0.07 mg/kg and 0.08-0.24 mg/kg, respectively. Under two spiked levels, the enrichment factors (EFs) and extraction recoveries (ERs) of the nine target analytes were 30.6-91.1 and 6.1%-18.2%, respectively. The recoveries of the nine target analytes ranged from 82.2% to 115.7% and the relative standard deviations (RSDs) (n=5) were less than 14.5% at low, medium and high levels. The developed method is straightforward, precise, sensitive, and well-suited for the rapid screening of preservatives in tobacco flavor samples.

Solvent-Focused Gas Chromatographic Determination of Thymol and Carvacrol Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction through Solidifying Floating Organic Droplets (USA-DLLME-SFO).

An ultrasound-assisted dispersive liquid-liquid microextraction by solidifying floating organic droplets, coupled to a form of temperature-programmed gas chromatography flame ionization detection, has been developed for the extraction and determination of thymol and carvacrol. This method utilizes undecanol as the extraction solvent, offering advantages such as facilitating phase transfer through solidification and enhancing solvent-focusing efficiency. The optimal gas chromatography conditions include a sample injection volume of 0.2 µL, a split ratio of 1:10, and a flow rate of 0.7 mL min-1. The extraction conditions entail an extraction solvent volume of 20 µL, a disperser solvent (acetone) volume of 500 µL, pH 7.0, 7.0% NaCl (3.5 M), a sample volume of 5.0 mL, an ultrasound duration of 10 min, and a centrifuge time of 7.5 min (800 rpm). These conditions enable the achievement of a high and reasonable linear range of 3.5 to 70. 0 µg mL-1 for both thymol and carvacrol. The detection limits are found to be 0.95 and 0.89 µg mL-1, respectively, for thymol and carvacrol. The obtained relative standard deviations, 2.7% for thymol and 2.6% for carvacrol, demonstrate acceptable precision for the purpose of quantitative analysis.

Hexafluoroisopropanol-based supramolecular solvent for liquid phase microextraction of pesticides in milk.

Residues of pesticides in milk may pose a threat to human health. This study aimed to develop a liquid-phase microextraction (LPME) method using hexafluoroisopropanol (HFIP)-based supramolecular solvent (SUPRAS) for the simultaneous extraction and purification of four pesticides (boscalid, novaluron, cypermethrin and bifenthrin) in milk. Pesticides were extracted using SUPRAS prepared with nonanol and HFIP, and the extraction efficiency was analyzed. Results showed satisfactory recoveries ranging from 80.8%-111.0%, with relative standard deviations (RSDs) of <6.4%. Additionally, satisfactory linearities were observed, with correlation coefficients >0.9952. The limits of quantification (LOQs) were in the range of 1.8 µg·L-1-14.0 µg·L-1. The established method demonstrated high extraction efficiency with a short operation time (15 mins) and low solvent consumption (2.7 mL). The HFIP-based SUPRAS LPME method offers a convenient and efficient approach for the extraction of pesticides from milk, presenting a promising alternative to conventional techniques.

Development of analytical method for determination of 1,3-dimethylamylamine in sports nutrition and bodybuilding supplements using pH-switchable deep eutectic solvents followed by high-performance liquid chromatography-diode array detector.

In this work, an easy, safe, simple, and efficient pH-switchable deep eutectic solvents (DESs)-based liquid phase microextraction followed by high-performance liquid chromatography-diode array detector analysis was developed for the determination of 1,3-dimethylamylamine (DMAA). The switchability of the obtained DESs was investigated by changing the pH. Then the best-selected DES was characterized and the application of the selected DES in the extraction of DMAA from sports nutrition and bodybuilding supplements was investigated. The DES synthesized from l-menthol: oleic acid in a molar ratio of 1:2 had the highest efficiency in the extraction of the target compound. Under the optimum conditions, (50 µL of DES, 100 µL of 4 mol/L KOH, 100 µL of 4 mol/L HCl, extraction time of 40 s and without salt addition) the calibration graph was linear in the range of 0.05-100 µg/kg and limit of detection was 0.02 µg/kg. The relative standard deviations including intra-day and inter-day for 10.0 µg/kg of DMAA in real samples were 2.7% (n = 7) and 5.3% (n = 7), respectively. The enrichment factor and percentage extraction recovery of the method were 283 and 85%, respectively. The relative recoveries for DMAA in different samples were in the range of 90%-109%.

Determination of Rhodamine 6G with direct immersion single-drop microextraction combined with an optical probe.

The combination of an optical probe and single-drop direct immersion microextraction (DI-SDME-OP) was used for the preconcentration and subsequent spectrophotometric determination of rhodamine 6G (Rh6G). The developed method is based on the formation of an ionic associate between Rh6G and picric acid at pH 3.0 and its extraction with amyl acetate. A microdrop of the organic phase was stably placed in the hole of an optical probe immersed in the sample solution. The absorbance of the extraction phase was monitored at 534 nm. The proposed method combines in a single step several stages of the analytical procedure, such as pre-concentration, phase separation, transfer of the extraction phase to the instrument and online measurement. The sensitivity of the proposed approach is not inferior to existing microextraction methods involving the combination of liquid-phase or solid-phase extraction with spectrophotometry or HPLC with a UV-Vis detector. The evaluation of the greenness of the developed method carried out by the AGREE method (0.58 points) showed that it outperforms other similar existing techniques using this parameter. The calibration plot for the determination of Rh6G by the DI-SDME-OP method was linear over the range of 10-500 nM with a correlation coefficient of 0.9956. The limit of detection was 3.4 nM. The accuracy and applicability of the method were evaluated by the determination of Rh6G in natural waters and lipstick.

Investigation of biodistribution by liquid-phase microextraction: Using a fatal diphenidol poisoning case.

Liquid-phase microextraction (LPME) possesses a high potential to isolate organic substances from different sample matrices. In this work, LPME was applied for the first time to investigate the biodistribution of diphenidol in different biofluids, organs, and brain regions using a fatal poisoning case. Since the LPME of diphenidol hasn't been reported, the effect of supported liquid membrane (SLM), acceptor and donor phases, and extraction time on LPME performance was investigated first. The solvents of 2-nonanone and 2-nitrophenyl octyl ether (NPOE) were found to be stable and efficient SLMs for LPME of diphenidol from biofluids and tissue samples, respectively. At steady state, the LPME recoveries for different sample matrices were in the range of 87 %-91 %. Due to the clean-up capability of LPME and the relatively high concentration of diphenidol in the fatal poisoning case, the proposed LPME systems were validated with related sample matrices using HPLC-UV for the determination. The methods displayed good linearity (R² ≥ 0.9943), and the limits of detection were 0.30 mg L-1, 0.28 mg L-1, and 2.7 µg g-1 for blood, urine, and liver samples, respectively. Meanwhile, the precision (≤13%), accuracy (90-110%), and matrices effect (±15%) were satisfactory at low, medium, and high concentrations. In addition, the stability, carryover, and dilution integrity met the requirements of ASB Standard 036. Finally, the proposed method was successfully applied to evaluate the biodistribution of diphenidol in five different biofluids, five organs, and six brain regions from a fatal poisoning case. Generally, the distribution of diphenidol in biofluids was lower than that in the organs and brain regions, and the highest concentration of diphenidol was observed in the liver, which is very important for the selection of inspection samples in forensic toxicological analysis. Therefore, LPME was proved to be a powerful tool for the investigation of biodistribution and postmortem redistribution in the fields of forensics.

Investigation of magnetic ionic liquids for selective and rapid extraction of gallic acid from complex samples using experimental, statistical modeling and density functional theory studies.

Given the high antioxidant capacity of gallic acid (GA), there is a great deal of interest in the development of rapid, selective, simple, and easily accessible analytical methods for its determination from complex samples. Consequently, the present study aimed to develop an ultrasonic assisted magnetic ionic liquid-based dispersive liquid microextraction (UA-MIL-DLLME) method for the extraction of GA from various samples prior to its spectrophotometric detection. The method's key variables were optimized through statistical analysis. Four magnetic liquids (MILs) were prepared and tested to extract the GA-Se complex formed in aqueous solution. Both experimental studies and theoretical calculations demonstrated that the most suitable MIL for the phase separation of the relevant complex is [P6,6,6,14][Mn(hfacac)3]. The developed UA-MIL-DLLME method exhibited a wide linear range (5-400 ng mL-1), a remarkable enhancement factor (133), and a low limit of detection (1.6 ng mL-1). Additionally, high extraction recovery (97 ± 1%) with a low relative standard deviation (1.9%) was achieved. The extraction time for the UA-MIL-DLLME method was 8 min. The precision of the method was evaluated through repeatability and reproducibility studies. Finally, the UA-MIL-DLLME method was successfully applied to the extraction of the GA from complex samples using a reference method.

Rhodamine and related substances in food: Recent updates on pretreatment and analysis methods.

Rhodamine, a colorant prohibited in various consumer products due to its demonstrated carcinogenic, mutagenic, and toxic properties, necessitates the development of a straightforward, efficient, sensitive, environmentally friendly, and cost-effective analytical method. This review provides an overview of recent advancements in the pretreatment and determination techniques for rhodamine across diverse sample matrices since 2017. Sample preparation methods encompass both commonly used pretreatment techniques such as filtration, centrifugation, solvent extraction, and cloud point extraction, as well as innovative approaches including solid phase extraction, dispersive liquid-liquid microextraction, hollow fiber liquid phase microextraction, magnetic solid phase extraction, and matrix solid phase dispersion. The analytical techniques encompass high performance liquid chromatography, surface-enhanced Raman scattering, and sensor-based methods. Furthermore, a comprehensive examination is conducted to offer insights for future research on rhodamine regarding the advantages, disadvantages, and advancements in various pretreatment and determination methodologies.

Lignin-based emulsive liquid-liquid microextraction for detecting triazole fungicides in water, juice, vinegar, and alcoholic beverages via UHPLC-MS/MS.

A universal, green, and rapid lignin-based emulsive liquid-liquid microextraction (ELLME) method was established to detect nine triazole fungicides in water, juice, vinegar, and alcoholic beverages via UHPLC-MS/MS. By employing an environmentally friendly emulsifier (lignin), the proposed ELLME was compatible with more extractants, and not restricted to fatty acids. Due to the high amphiphilic properties and three-dimensional structure of lignin, the emulsion was quickly formed through several aspirate-dispense cycles of the green extractant (guaiacol) and lignin solution. And a micropipette was used for rapid microextraction. The limit of detection was 0.0002-0.0057 µg L-1. The extraction recoveries and relative standard deviation were 81.7%-102.0% and 0.9%-7.1%, respectively. Finally, three green metric tools were used to verify the greenness of the whole procedure. The proposed lignin-based ELLME successfully emulsified green solvents, indicating that emerging solvents may be excellent alternatives as extractants in ELLME for pesticide residue analysis in food samples.

Deep Eutectic Solvents-Based Ultrasonic-Assisted Dispersive Liquid-Liquid Microextraction for the Determination of Organophosphorus Pesticides in Honeysuckle Dew Samples.

A deep eutectic solvent (DES) with the ability to change from hydrophilic to hydrophobic was designed and synthesized and applied to the determination of organophosphorus (OPP) pesticides in honeysuckle dew samples. Choline chloride, phenol, and tetrahydrofuran (THF) were used as the hydrogen bond acceptor, hydrogen bond donor, and demulsifier, respectively. Eight OPP pesticides were extracted by DES coupled with ultrasonic-assisted extraction (UA) and then chromatographed by GC-MS. DES used as an extract solvent has the advantages of high extraction efficiency, low cost, and environmental protection. Furthermore, DES is compatible with GC-MS. The single factor experiment design and Box-Behnken design (BBD) were applied to the optimization of experimental factors, including the type and composition of extraction solvent, type of demulsifier solvent, the volume of DES and THF, pH of sample solution, and ultrasonic time. Under the optimum experimental conditions, the high degree of linearity from 0.1 to 20.0 ng mL-1 (R2 ≥ 0.9989), the limits of detection from 0.014 to 0.051 ng mL-1 (S/N = 3), and the recoveries of analytes from 81.4 to 104.4% with relative standard deviation below 8.6%. In addition, the adsorption mechanism of OPPs on DES was explored by adsorption kinetic studies. These results have demonstrated that the present method has offered an effective, accurate, and sensitive methodology for OPP pesticides in honeysuckle dew samples, and this method provides a reference for the detection of pesticide residues in traditional Chinese medicine.

Ionic-liquid/Carbowax 20 M functionalized capsule phase microextraction platform for the extraction of phosphodiesterase-5 inhibitors from human serum and urine prior to their determination by LC-MS.

Capsule phase microextraction (CPME) is an efficient bioanalytical technique that streamlines the sample preparation by integrating the filtration and stirring mechanism directly into the device. A novel composite sorbent designed to be selective towards the target analytes consisting of mixed-mode sorbent chemistry synthesized by sol-gel technology is found promising and superior to the conventional C18 sorbents. Herein we describe the encapsulation of an ionic liquid (IL)/Carbowax 20M-functionalized sol-gel sorbent (sol-gel IL/Carbowax 20 M) in the lumen of porous polypropylene tubes for the capsule phase microextraction of three phosphodiesterase-5 inhibitors namely avanafil, sildenafil, and tadalafil in human serum and urine samples. The CPME device was characterized by Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FT-IR). The experimental parameters of CPME procedure (e.g. sample pH and ionic strength, extraction time, stirring rate, elution solvent and volume) were carefully optimized to achieve the highest possible extraction efficiency for the analytes. Method validation was conducted in terms of precision, linearity, accuracy, matrix effect, lower limits of quantification, and limits of detection (LOD). The method linearity was investigated in the range of 50-1000 ng mL-1 for all analytes while the precision was less than 11.8 % in all cases. For all analytes, the LOD values were 17 ng mL-1. The IL/CW 20M-functionalized microextraction capsules could be reused at least 25 times both for urine and serum samples. The green character and the applicability of the proposed method were evaluated using the ComplexGAPI and BAGI indexes. The optimized CPME protocol exhibited reduced consumption of organic solvent and generation of waste, cost-effectiveness, and simplicity. Finally, the proposed method was successfully applied to the analysis of sildenafil in human urine after administration of drug-containing formulation.

A novel indicator for lead poisoning beyond blood lead level: Facile diagnosis of lead poisoning using random urine with point-of-care testing.

Lead (Pb) poisoning is estimated to account for 1 % of the global disease burden. The gold standard for diagnosing lead poisoning in human body relies on blood lead level (BLL), which is always performed in hospitals using expensive instruments. However, there are still many countries and regions with a lack of medical resources (without enough professional medical staff and analytical instruments). To achieve a facile diagnosis of lead poisoning by ordinary residents (without any expertise), this study conducted a research study on 810 participants to discover and validate a new lead poisoning indicator (creatinine-corrected urinary lead level, cULL) beyond BLL in non-invasive samples. A point-of-care testing (POCT) device to measure cULL was developed, equipped with liquid-phase microextraction and electromembrane extraction on a paper-based analytical device for on-site separation of lead and creatinine in the urine, using a smartphone for the quantification of analytes. The cULL as a novel indicator and the POCT device developed could be effective in reducing the risk of damage from lead contamination.