Search Results (88)

The widespread use of antibiotics in human medicine, veterinary care, and livestock production has resulted in their frequent detection in diverse environmental and food matrices, making continuous surveillance of antibiotic residues in food products essential for consumer protection. In this study, a sustainable analytical method based on dispersive liquid–liquid microextraction (DLLME) coupled with UHPLC–MS/MS was developed for the trace determination of sulfamethoxazole, sulfadimethoxine, and enrofloxacin in commercial cow milk and chicken eggs. A natural deep eutectic solvent (NADES) composed of anisaldehyde and octanoic acid (2:1, molar ratio) was employed as a biodegradable extraction solvent, and key extraction parameters were systematically optimized. Under optimized conditions, the method demonstrated excellent linearity (R² ≥ 0.9982), recoveries of 89.5–98.7%, and RSDs ≤ 6.04%. Application to 44 commercial samples from the Saudi market revealed sulfamethoxazole as the most frequently detected antibiotic, occurring in 90% of egg samples (2.17–13.76 µg kg⁻¹) and 70.8% of milk samples (0.26–26.67 µg L⁻¹). A comprehensive evaluation using ten metrics confirmed the method’s greenness, practicality, analytical performance, and innovation. Overall, the proposed NADES–DLLME–UHPLC–MS/MS approach offers a rapid, cost-effective, and environmentally friendly alternative for routine monitoring of antibiotic residues in food matrices. Full article

The application of Green Analytical Chemistry (GAC) principles in method development aims to reduce waste and replace hazardous solvents with environmentally friendly alternatives. Natural Deep Eutectic Solvents (NADESs) have recently emerged as sustainable replacements for traditional organic solvents. In this study, hydrophobic NADESs were used in dispersive liquid–liquid microextraction (DLLME) to extract four synthetic hallucinogenic phenethylamines (2C-B, 25B-NBOMe, 25C-NBOMe, and 25I-NBOMe) in urine samples. Nine NADESs were formed using menthol and different organic acids, with menthol–decanoic acid (1:1 molar ratio) providing the best extraction efficiency. A fractional factorial design identified pH, vortex speed, and vortex time as key factors, which were then optimized using a Box–Behnken design. The statistical model showed strong validity and high predictive power, and the optimal conditions (pH 12, vortex time 20 s, vortex speed 30,000 rpm, centrifugation at 14,000 rpm for 3 min) resulted in the highest recoveries. Greenness and operational sustainability, evaluated using ComplexGAPI, AGREEprep, BAGI, and SPRS tools, revealed clear advantages over existing extraction approaches. Overall, the proposed method represents a sustainable, white-chemistry–driven microextraction strategy suitable for clinical and forensic toxicological applications. Full article

Accurate and sensitive determination of hormones in biological matrices is essential for clinical diagnostics, therapeutic monitoring, and endocrine research. However, hormone determination presents significant challenges due to their typically low concentrations, complex sample matrices, and structural diversity. In recent years, microextraction techniques have emerged as strategic tools in bioanalytical chemistry, offering advantages in terms of miniaturization, enhanced selectivity, and compatibility with the principles of green analytical chemistry (GAC). This review provides a comprehensive overview of green and emerging microextraction approaches for the determination of steroidal, thyroid, peptide, and other hormones in biological samples. Key techniques such as solid-phase microextraction (SPME) and dispersive liquid–liquid microextraction (DLLME), followed by high-performance liquid chromatography (HPLC) coupled to diode array detectors (DADs) or mass spectrometry (MS), are critically discussed. Special emphasis is placed on the use of environmentally friendly solvents, such as deep eutectic solvents (DESs), supramolecular solvents (SUPRASs), and advanced sorbents including molecularly imprinted polymers (MIPs) and nanostructured magnetic phases. Applications across various bioanalytical matrices (urine, plasma, serum, saliva, tissues…) are examined in terms of sensitivity, selectivity, and validation parameters. Finally, current challenges, method development gaps, and future directions are highlighted to support the continued advancement of sustainable hormone determination in complex biological systems. Full article

In the present investigation, a novel dispersive liquid–liquid microextraction (DLLME) method was developed for the spectrophotometric determination of Hg²⁺. Fe(II) phthalocyanine (Fe(II)Pc) was employed as the sensor, chloroform (300 µL) as the extraction solvent, and ethanol (700 µL) as the dispersive solvent. Following the formation of the Hg²⁺:Fe(II)Pc complex, the sample was centrifuged at 1000 rpm for 2 min. The aqueous phase was discarded, and the extraction phase was diluted to 250 µL with methanol and transferred into a 250 µL quartz cell for spectrophotometric measurement at 276 nm. The method exhibited a linear range of 1–20 µg/L, with limits of detection (LOD) and quantification (LOQ) calculated as 1.44 µg/L and 4.80 µg/L, respectively. The enrichment factor was determined to be 105, and the optimum pH for the procedure was 2.0. Full article

Crustaceans are particularly sensitive to copper toxicity, and although the downstream effects of increased copper exposure on the metabolome are often postulated and observed, they are rarely measured. To perform absolute quantification of hydrophilic small-molecule metabolites in the hemolymph of the crustacean Cancer borealis, we derivatized targeted metabolites related to copper toxicity using in-house-developed isotopic N,N-dimethyl leucine (iDiLeu) tags. Selected analytes were pooled at previously determined concentrations to serve as internal standards, and a calibration curve was generated. The sample loss was minimized by optimizing the derivatization-assisted sample cleanup using dispersive liquid–liquid microextraction (DLLME) and hydrophilic–lipophilic balancing (HLB). Calibration curves were then used for the absolute quantification of metabolites of interest following 30 min, 1 h, and 2 h exposures to 10 µM CuCl₂. We found that glutamic acid was downregulated after 2 h of copper exposure, which may disrupt cellular metabolism and increase oxidative stress in crustaceans. These changes could have significant impacts on crustacean populations and the ecosystems they support. Full article

The widespread discharge of industrial and urban waste has led to significant increases in the environmental concentrations of numerous chemical substances. This work presents the development of a simple and environmentally friendly dispersive liquid–liquid microextraction (DLLME) method based on a hydrophobic natural deep eutectic solvent (NADES) for the determination of selected compounds from benzotriazole, benzothiazole, paraben, and UV filter families in wastewater samples. Of the twelve NADES formulations evaluated, those composed of a 4:1 molar ratio of thymol and menthol presented the highest extraction efficiencies. The influence of key experimental variables such as the pH of the aqueous sample, the ratio of NADES phase to sample volume, and the extraction time on the extraction efficiency was investigated using a multivariate optimization. Under optimal conditions, relative standard deviations below 15% and recoveries for spiked wastewater samples ranged between 82 and 108%, demonstrating the suitability of the method for routine water-quality monitoring. The sustainability and practicality of the developed method was evaluated using the assessment tools ChlorTox, AGREEprep, AGRRE, and BAGI, obtaining scores of 0.005 g in the NADES-DLLME method, 0.70, 0.52, and 72.5, respectively, demonstrating that the method is green and reliable. Full article

The analysis of wastewater is essential in environmental chemistry, particularly for monitoring emerging contaminants and assessing ecological impacts. In this context, hyphenated chromatographic techniques are widely used, with liquid chromatography being one of the most common. However, gas chromatography coupled with mass spectrometry (GC-MS) remains a valuable tool in this field due to its sensitivity, selectivity, and widespread availability in most laboratories. This review examines the application of validated methods for wastewater analysis using GC-MS (MS), highlighting its relevance in identifying micropollutants such as pharmaceuticals, drugs of abuse, pesticides, hormones, and industrial by-products. The validation of analytical methods is crucial to ensuring the reliability and reproducibility of data and the accurate monitoring of contaminants. Key parameters, including sample volume, recovery efficiency, and detection and quantification limits, are discussed, evaluating different approaches to optimising the identification of different classes of contaminants. Additionally, this study explores advances in sample preparation techniques, such as solid-phase microextraction (SPME), dispersive liquid–liquid microextraction (DLLME), and solid-phase extraction (SPE), which enhance efficiency and minimise interferences in the analysis. Finally, future perspectives are discussed, including the integration of emerging technologies such as high-resolution mass spectrometry, the miniaturisation of GC systems, and the development of faster and more sustainable analytical methods. Full article

Dispersive liquid–liquid microextraction (DLLME) is an economical, rapid, sensitive, and environmentally friendly miniaturized liquid–liquid extraction format. It has been successfully applied in trace element analysis since 2006 when it was first proposed. This article describes a new dispersive liquid–liquid microextraction method for the determination of trace amounts of Co²⁺. In brief, this method involves the extraction of Co²⁺ from the sample to the trichloromethane phase by the dispersive action of methanol after the formation of a complex with a novel 9-(methylaminomethyl)anthracene-Ni(II) phthalocyanine (MAMA Ni(II)Pc 2) as a sensor. The first step in this study was the synthesis and characterisation of the sensor. Later, the proposed method was optimized with respect to various parameters such as extraction and dispersive solvents and their amounts, pH, sensor concentration, and centrifugation time and rate. The calibration graph was linear between 0.40 and 260 µg/L, with an R² of 0.9978. The limit of detection and limit of quantification were found to be 0.19 µg/L and 0.46 µg/L, respectively. To evaluate the precision of this method, the analysis of a 50 µg/L Co²⁺ solution was carried out. The intra-day and inter-day relative standard deviation values were calculated as 1.7% and 2.4%, respectively (n = 7). The accuracy of the proposed method was investigated by means of a standard addition/recovery test. Full article

Cannabis remains the most widely used illicit drug worldwide, identifying it is a routine procedure in forensic toxicology. Due to its widespread use, there is a need for analytical methods that can detect it in biological samples. Hair is of particular interest in forensic toxicology as it is the only biological sample that enables retrospective analysis of consumption. In addition, collecting hair is non-invasive, and the specimens can be stored at room temperature. However, the sample preparation process for hair is tedious and multi-step. To address this issue, this study introduces a novel approach to preparing hair samples for analysis, based on air-assisted liquid–liquid microextraction (AALLME). This technique is a modification of dispersive liquid–liquid microextraction (DLLME), which eliminates the need for dispersants and chlorinated organic solvents as extractants. Both techniques offer sustainable alternatives to conventional liquid–liquid extraction (LLE) and solid-phase extraction (SPE), making them of interest in forensic toxicology. This study is the first to report the application of AALLME to the hair matrix. A mixture of cyclohexane and ethyl acetate (9:1) was used as the extractant solvent. Gas chromatography–mass spectrometry (GC–MS) was then used to determine and quantify THC. The method was validated according to FDA guidelines and demonstrated good linearity within the 0.01–4 ng/mg range. The limits of detection (LOD) and quantification (LOQ) were 0.008 and 0.01 ng/mg, respectively. Finally, the applicability of the method was evaluated by analyzing hair samples received by the Forensic Toxicology Service. Full article

In this review, a 5-year overview on environmentally friendly approaches for the extraction of the most relevant organic pollutants in soil, sediment, particulate matter, and sewage sludge coupled with chromatographic analysis is reported. Organic contaminants encompass various compounds derived from personal care products, industrial chemicals, microplastics, organic matter combustion, agricultural practices, and plasticizer material. The principles of green analytical chemistry (GAC) and green sample preparation (GSP) serve as a guideline for the development of more environmentally sustainable analytical protocols. This study focuses attention on microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), matrix solid-phase dispersion (MSPD), and microextraction techniques, such as solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), hollow-fiber liquid-phase microextraction (HF-LPME), spray-assisted droplet formation-based liquid-phase microextraction (SADF-LPME), and dispersive liquid–liquid extraction (DLLME). These approaches represent the most relevant eco-friendly sample preparation for the advanced extraction of target analytes from environmental solid samples. Full article

Strigolactones (SLs) are key hormones regulating branching and tillering in rice, impacting plant architecture and yield. A rapid, sensitive, and environmentally friendly method using dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO), coupled with ultra-high-performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS), has been developed for the determination of three SLs (strigol, orobanchol, and 5-deoxystrigol). The DLLME-SFO method integrates one-step low-temperature extraction and enrichment. The DLLME-SFO conditions were optimized through a single-factor experimental design. Under the best-tested conditions, the developed method exhibited excellent linearity, with the coefficient of determination (R²) values greater than 0.9993. The recoveries ranged from 83% to 96%, with precision values ranging from 4.5% to 12.4%. The limits of detection (LODs) varied from 0.6 to 1.2 pg/g fresh weight, indicating the high sensitivity of the method. Additionally, a novel assay protocol for the quantification of SLs in rice in response to nitrogen and phosphorus stress conditions was applied. Full article

Beryllium (Be) is one of the most toxic non-radioactive elements on the periodic table, and its presence or intake can negatively impact both the environment and human health. Classified as a carcinogen, Be is dangerous even at trace concentrations, stressing the necessity of developing reliable methods for quantifying it at very low levels. Spectrometric techniques for quantifying Be vary in sensitivity and applicability, with inductively coupled plasma mass spectrometry (ICP-MS) being the most sensitive for ultra-trace analysis. Flame atomic absorption spectrometry (FAAS) is suitable for higher Be concentrations, but preconcentration techniques can significantly lower detection limits. Electrothermal atomic absorption spectrometry (ETAAS) provides enhanced sensitivity for low-level Be quantification, further optimized using pyrolytically coated graphite tubes and chemical modifiers such as Mg(NO₃)₂ or Pd(NO₃)₂. Effective separation and preconcentration techniques are essential for reliable Be quantification in complex matrices. Liquid-liquid extraction (LLE), including single-drop microextraction (SDME) and dispersive liquid-liquid microextraction (DLLME), have evolved to reduce the use of hazardous solvents. When combined with ETAAS, surfactant-assisted DLLME using agents like cetylpyridinium ammonium bromide (CPAB) and dioctyl sodium sulfosuccinate (AOT) achieves preconcentration factors of approximately 25, reducing LOD to 1 ng/L. Vesicle-mediated DLLME coupled with ETAAS further enhances sensitivity, allowing detection limits as low as 0.01 ng/L in seawater. Cloud-point extraction (CPE), often employing Triton X-114, facilitates Be extraction using complexing agents or nanomaterials like graphene oxide. These advancements are critical for accurately quantifying Be at ultra-trace levels in diverse environmental and biological samples, overcoming challenges posed by low analyte concentrations and matrix interferences. Full article

Beta-blockers are pharmaceuticals used to treat cardiovascular diseases such as hypertension, angina pectoris, and arrhythmia. Due to high consumption, they are continuously released into the environment, being detected in many aqueous matrices. The aim of this research is to test the effectiveness of two green liquid-phase microextraction procedures, such as dispersive liquid–liquid microextraction (DLLME) and solidification of floating organic droplet microextraction (SFOME) for the selective extraction of eight beta-blockers (atenolol, nadolol, pindolol, acebutolol, metoprolol, bisoprolol, propranolol, and betaxolol) from aqueous matrices for their analysis by gas chromatography (GC) or liquid chromatography (LC). The influence of extraction parameters, such as the type and volume of extraction and disperser solvents, and ionic strength were studied. The developed extraction procedures provide a good enrichment factor for six compounds (61.22–243.97), good extraction recovery (53.04–92.1%), and good sample cleaning for both extraction procedures. Good limits of detection (0.13 to 0.69 µg/mL for GC and 0.07 to 0.15 µg/mL for HPLC) and limits of quantification (0.39 to 2.10 µg/mL for GC and 0.20 to 0.45 µg/mL for LC) were obtained. The developed procedures were successfully applied to the analysis of selected beta-blockers in wastewater samples, proving their applicability to the real samples. Full article

A miniaturised, eco-friendly and efficient multiclass method for the simultaneous determination of 87 veterinary drugs, pesticides and mycotoxin residues in beef muscle samples by ionic liquid-based dispersive liquid–liquid microextraction (IL–DLLME) and liquid chromatography tandem mass spectrometry (LC–MS/MS) was developed and validated according to Commission Implementing Regulation (EU) 2021/808 and ISO/IEC 17025: 2017. Under IL–DLLME optimum conditions, matrix calibration yielded a coefficient of determination (R²) ranging from 0.99942 to 0.99997. The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.93 to 23.78 µg kg⁻¹ and from 1.98 to 38.27 µg kg⁻¹, respectively. Recoveries ranged from 80.0 to 109.8% and the decision limit (CCα) values ranged from 13.0 to 523.0 µg kg⁻¹. Repeatability and reproducibility values were achieved in the ranges of 1.55–12.91% and 1.44–13.35%, respectively. The validated method was applied to 50 real beef samples and 12% of the tested samples contained traces of some residues, but they were all below their respective LOQs and CCα; hence, the beef was fit for human consumption. The greenness of the method was assessed using five green analytical chemistry (GAC) metrics, namely, the Analytical Eco-Scale (AES), NEMI, GAPI, AGREE and ComplexGAPI, and found to be green according to the AES metric and Analytical GREEnness Metric Approach and Software (AGREE). The method provided better results at a greatly reduced cost and analysis time in comparison with standard method. Full article

Background/Objectives: This study reports the development of a straightforward, efficient, and cost-effective dispersive liquid–liquid microextraction (DLLME) method for the gas chromatography–mass spectrometry (GC-MS) analysis of volatile compounds present in wine. Methods: Four critical parameters were optimised using a D-optimal design to maximise extraction outcomes of the targeted analytes from a 10 mL sample, while minimising interference from other compounds. The analytical characteristics of the method were assessed using 36 target compounds. Results: The method provided satisfactory linearity (correlation coefficients > 0.990), good repeatability for both for intra- and inter-day measurements (RSD < 10.3%), and suitable recoveries of target analytes from both model (83–110%) and real matrices (80–120%). The validated method was subsequently applied to analyse the aroma profile of 30 New Zealand Pinot noir (PN) wine samples. Conclusions: This study contributes to the advancement of analytical techniques available to both industry and researchers to explore the complex aroma profiles of wines. Full article