Microextraction Technique Research Articles

Development of UV‐Vis spectroscopy-based analysis method for determination of tin(IV) in epilobium parviflorum (hoary willowherb) tea using deep eutectic solvent based preconcentration

In this study, a UV–Vis Spectroscopy-based method was developed for the determination of tin(IV) in epilobium parviflorum tea samples after preconcentration. The preconcentration process was carried out using the liquid-liquid microextraction technique. Before starting the analysis, optimization studies were carried out for the variables likely to affect the experimental results. As a result of the analyzes performed under optimum conditions, the detection limit of our method was calculated as 16.83 μg/L. The percent relative standard deviation value was calculated as 1.25% (n = 8) and linearity was found in the range of 10–1000 μg/L. Recovery experiments were performed on epilobium parviflorum tea samples using the matrix matching method. As a result of the analyzes made on teas belonging to three different brands, recovery results ranging from 92 to 117% were obtained.

Greenness assessment of microextraction techniques in therapeutic drug monitoring.

Aim: In this study, we evaluated the greenness and whiteness scores for microextraction techniques used in therapeutic drug monitoring. Additionally, the cons and pros of each evaluated method and their impacts on the provided scores are also discussed. Materials & methods: The Analytical Greenness Sample Preparationmetric tool and white analytical chemistry principles are used for related published works (2007-2023). Results & conclusion: This study provided valuable insights for developing methods based on microextraction techniques with a balance in greenness and whiteness areas. Some methods based on a specific technique recorded higher scores, making them suitable candidates as green analytical approaches, and some others achieved high scores both in green and white areas with a satisfactory balance between principles.

ISFME extraction of As species from some real water samples using an imidazolium-based task-specific ionic liquid (TSIL): Synthesis and characterization

ABSTRACT To determine of arsenic species in real water samples using electrothermal atomic absorption spectrometry, a high-performance in-situ solvent formation microextraction technique has been developed using homogenous liquid – liquid microextraction concepts. The developed method was based on the use of a synthesized imidazolium-based ionic liquid (IL) modified with ammonium pyrrolidine dithiocarbamate as a task-specific ionic liquid (TSIL), which was chelated with As(III) and then converted to a hydrophobic IL using ammonium hexafluorophosphate in anion exchange reactions. As(V) was reduced to As(III), using a satisfied reducing agent, and the total amount of As was analyzed using ETAAS. TSIL acts simultaneously as an extracting solvent and a chelating agent. The characterization of the synthesized TSIL was performed using13CNMR and FTIR analyses. When optimal conditions were met, linear dynamic ranges of 0.5–50 µg/L and 0.5–20 µg/L were obtained in the determination of As(III) and total As, respectively. The limits of detection (LOD) and quantitation (LOQ) were determined to be 0.021 µg/Land 0.064 µg/L for the determination of As(III) (for concentration 20 µg/L), respectively, and the standard deviation (RSD%, n = 7) was 2.0%. To evaluate the validity of the method, it was successfully applied for As species determination in different real water samples.

Recent overview of microextraction of metal ions and pharmaceuticals by solidified floating organic drop microextraction techniques

AbstractThis work presents a comprehensive overview of solidified floating organic drop microextraction, with a particular emphasis on its applications in the analysis of heavy metal ions and different pharmaceutical compounds by sample pretreatment, complexation, and their identification by various analytical techniques. Here, we discussed basic principles, procedures, applications of the technique, and effects of different variables like pH, temperature, stirring rate, extraction time, salts addition, extraction solvent and extraction volume, centrifugation speed, and, vortex time on preconcentration. In brief, the review summarises the various modes of solidified floating organic drop microextraction such as dispersive liquid‐liquid microextraction, ultrasound‐assisted, air‐assisted liquid‐liquid microextraction, and vortex‐assisted solidified floating organic drop microextraction. this review covers the methods combined with analytical techniques such as inductively coupled plasma‐optical emission spectrometry, electrothermal atomic absorption spectrometry, flame atomic absorption spectroscopy, graphite furnace atomic absorption spectrometry, electrothermal vaporization inductively coupled plasma mass spectrometry, high‐performance liquid chromatography, and gas chromatography/mass spectrometry. among these, the incorporation of ultrasonic, vortex, and air agitation improves the dispersion mechanism. The coupling of solidified floating organic drop microextraction with other techniques enhances the selectivity and efficiency of the preconcentration procedure. This review provides a potential overview of the fundamental principles, advancements in various modes, influencing factors, and applications of solidified floating organic drop microextraction, showing its potential for advancements in sample preparation and analytical methodologies across various domains.

Method development for an untargeted HS-SPME-GC–MS analysis of terpenes and cannabinoids for the geographical sourcing of Marijuana

Despite growing decriminalization of Cannabis sativa (i.e., marijuana) possession throughout the United States of America, there remains to be an ongoing interest in the detection of unlawfully possessed and transported marijuana. This issue has resulted in an increasing interest regarding the generalization and specification related to the canine detection of marijuana. More specifically, canine trainers have expressed concerns on whether canines can generalize on the odor of marijuana regardless of the origin of their training materials. This research aims to differentiate multiple marijuana headspace samples from three regions in the USA based solely on the volatile organic compounds (VOCs) found in their odor profiles. In this study, a heated headspace solid phase micro-extraction (SPME) technique was optimized and implemented for the collection of both volatile terpenes and cannabinoids from marijuana. The headspace samples were analyzed using two full-scan, untargeted, optimized methods on a gas chromatograph coupled to a mass spectrometer (GC–MS), and a variety of chemometric tools were applied to the data to enable differentiation and potential classification between sample populations. Principal component analysis and sparse partial least squares discriminant analysis (sPLS-DA) employed in this study have demonstrated a disparity between marijuana varieties based on geography using the VOCs extracted from their odor profiles. With this research, it is intended to determine some fundamental differences between Cannabis of different geographical origins and set a foundation for the development and advancement of instrumental applications for other non-contact marijuana detection techniques in support of the improvement of illicit substance detection technology.

Vortex-blending matrix solid-phase dispersion and UPLC-Q-TOF/MS were proposed to extract and examine the urushiols from Toxicodendron vernicifluum bark

Toxicodendron vernicifluum bark has been used for many years as a component in foods and as a traditional herbal medication. Unfortunately, the presence of urushiols, which induce allergies, limits its application. This study used a vortex-blending matrix solid-phase dispersion microextraction technique to extract urushiols from Toxicodendron vernicifluum bark. HPLC was used to evaluate the amounts of the extracted urushiols (15:0, 15:1, 15:2, and 15:3). The modified magnetic adsorbent was prepared through an in situ coprecipitation method and characterized using a variety of techniques. The optimized extraction conditions are as follows: using magnetic Zeolite Socony Mobil-Five as an adsorbent, a 1:2 sample/adsorbent ratio, 2.5 min of vortex-blending time, 4 mL of 0.1% (V/V) trifluoroacetic acid-methanol as the elution solvent and 8 min of ultrasound time. There was good linearity and high repeatability in the method. Furthermore, the limits of detection for the urushiols ranged from 0.20 to 0.50 μg/mL. Under the optimized conditions, 50 compounds were identified by ultra high performance liquid chromatography and quadrupole time-of-flight mass spectrometry. These compounds included 8 phenolic acids, 9 monomeric urushiols, 11 urushiol dimers, 10 other components, and 11 flavonoids. The suggested approach, which has the advantages of few stages and high extraction efficiency over existing extraction procedures, is a potentially useful method for obtaining and evaluating urushiols in raw materials or extracts.

Rearing and 60Co radiation do not affect attractiveness but alter the volatile profiles released by Anastrepha obliqua calling males.

Calling males of Anastrepha obliqua release volatile compounds to attract conspecific males to form leks and females to mate. Male volatiles from Mexican and Brazilian populations of A. obliqua have been previously identified. However, there are differences in the number and identity of volatile compounds between the populations. These differences in volatile profiles may be due to male origin (e.g. wild or mass-reared flies) or methodological issues (e.g. sampling techniques). In this study, we evaluated the attractiveness of wild, laboratory non-irradiated, and laboratory-irradiated flies under semi-field conditions. Male volatiles were collected using dynamic headspace sampling (DHS) and solid-phase microextraction (SPME) techniques, and identified using gas chromatography-coupled mass spectrometry. The results showed no difference in the attractiveness of wild, laboratory non-irradiated, and irradiated males to females. However, the number of captured females differed according to the origin; wild and non-irradiated females were captured more frequently than the irradiated flies. A total of 21 compounds were found using SPME, whereas only 12 were collected using DHS, although the relative amounts of these compounds were higher than those obtained using the former sampling technique. In addition, only laboratory non-irradiated males released α-pinene and menthol, which have not been previously reported in this fruit fly species. Additionally, we identified novel compounds in A. obliqua; however, certain compounds previously reported were not detected. This study suggests that despite the qualitative and quantitative variations in the volatile profiles of A. obliqua males, their attractiveness was unaffected.

Trichoderma afroharzianum TRI07 metabolites inhibit Alternaria alternata growth and induce tomato defense-related enzymes

Identifying a viable substitute for the limited array of current antifungal agents stands as a crucial objective in modern agriculture. Consequently, extensive worldwide research has been undertaken to unveil eco-friendly and effective agents capable of controlling pathogens resistant to the presently employed fungicides. This study explores the efficacy of Trichoderma isolates in combating tomato leaf spot disease, primarily caused by Alternaria alternata. The identified pathogen, A. alternata Alt3, was isolated and confirmed through the ITS region (OQ888806). Six Trichoderma isolates were assessed for their ability to inhibit Alt3 hyphal growth using dual culture, ethyl acetate extract, and volatile organic compounds (VOCs) techniques. The most promising biocontrol isolate was identified as T. afroharzianum isolate TRI07 based on three markers: ITS region (OQ820171), translation elongation factor alpha 1 gene (OR125580), and RNA polymerase II subunit gene (OR125581). The ethyl acetate extract of TRI07 isolate was subjected to GC–MS analysis, revealing spathulenol, triacetin, and aspartame as the main compounds, with percentages of 28.90, 14.03, and 12.97%, respectively. Analysis of TRI07-VOCs by solid-phase microextraction technique indicated that the most abundant compounds included ethanol, hydroperoxide, 1-methylhexyl, and 1-octen-3-one. When TRI07 interacted with Alt3, 34 compounds were identified, with major components including 1-octen-3-one, ethanol, and hexanedioic acid, bis(2-ethylhexyl) ester. In greenhouse experiment, the treatment of TRI07 48 h before inoculation with A. alternata (A3 treatment) resulted in a reduction in disease severity (16.66%) and incidence (44.44%). Furthermore, A3 treatment led to improved tomato growth performance parameters and increased chlorophyll content. After 21 days post-inoculation, A3 treatment was associated with increased production of antioxidant enzymes (CAT, POD, SOD, and PPO), while infected tomato plants exhibited elevated levels of oxidative stress markers MDA and H2O2. HPLC analysis of tomato leaf extracts from A3 treatment revealed higher levels of phenolic acids such as gallic, chlorogenic, caffeic, syringic, and coumaric acids, as well as flavonoid compounds including catechin, rutin, and vanillin. The novelty lies in bridging the gap between strain-specific attributes and practical application, enhancing the understanding of TRI07’s potential for integrated pest management. This study concludes that TRI07 isolate presents potential natural compounds with biological activity, effectively controlling tomato leaf spot disease and promoting tomato plant growth. The findings have practical implications for agriculture, suggesting a sustainable biocontrol strategy that can enhance crop resilience and contribute to integrated pest management practices.

Development of a dispersive liquid–liquid microextraction procedure based on a natural deep eutectic solvent for ligand-less preconcentration and determination of heavy metals from water and food samples

In the current study, a ligand-less dispersive liquid–liquid microextraction technique assisted ultrasound and vortex equipment (DLLME-A-US-V) procedure was used for the simultaneous preconcentration and extraction of heavy metal ions. The proposed method was done by a natural hydrophobic deep eutectic solvent for the extraction of arsenic, cadmium, lead, and mercury ions without a complexing agent. The natural deep eutectic solvent was prepared from l-menthol (M) and salicylic acid (SA). The precursor of deep eutectic solvents strongly affects the extraction of metal ions. Among the studied solvents, hydrophobic deep eutectic solvents showed the highest extraction recovery. Under optimal experimental conditions, the method linearity, limits of detection (LOD), limits of quantification (LOQ), relative standard deviations (RSD %), enrichment factors (EF), and extraction recovery (% ER) were equal to 0.005–14 µg/L, 0.0043–0.0088 µg/L, 0.0143–0.0294 µg/L, 1.66–2.83 %, 112–120, and 90–96 %, respectively. The obtained coefficients of determination (r2) were also higher than 0.991. This method was successfully applied to determine some heavy metals in food samples in the ultra-trace range with the recovery values of real samples being 93–108 %.

Advanced micro-extraction techniques (SPME, HiSorb) for the determination of goat cheese whey wastewater VOCs

HiSorb and solid-phase microextraction (SPME), two environmentally friendly micro-extraction techniques based on the same fundamental principles, were evaluated for their extraction efficiency of volatile organic compounds (VOCs) from goat cheese whey wastewater. For this purpose, a sample preparation method based on the headspace-HiSorb technique was developed and evaluated for its efficiency in terms of the amount of extracted compounds and reproducibility of results. Thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) and GC/MS analytical methods were used to perform the wastewater analysis, respectively. The experimental parameters of HiSorb were evaluated in terms of probe coating, extraction time, stirring speed, sample volume, extraction temperature and salt addition. Under optimal extraction conditions, it was observed that the use of the divinylbenzene/carbon wide range/polydimethylsiloxane (DVB/CWR/PDMS) triple coating for HiSorb and DVB/Carboxen (CAR)/PDMS for SPME, was best suited to extract a broader range of VOCs with higher peak intensities. A total of 34 VOCs were extracted and determined with the DVB/CWR/PDMS HiSorb probe, while only 23 VOCs were determined with the conventional DVB/CAR/PDMS SPME fiber. The DVB/CWR/PDMS HiSorb probe has a higher adsorbent capacity which results in a higher sensitivity for VOCs compared to the DVB/CAR/PDMS SPME fiber. Furthermore, the HiSorb technique exhibits better reproducibility, as indicated by the lower relative standard deviation (RSD) of 3.7% compared to 7.1% for SPME. Therefore, the HiSorb technique is an effective method for detecting VOCs in complex matrices, such as wastewater.

Salt-assisted liquid–liquid microextraction for determination of haloperidol in human plasma by LC-MS/MS

Haloperidol is an antipsychotic used in the treatment of schizophrenia. Compared to other antipsychotics, it is widely used in developing countries due to its affordable price. Haloperidol has a narrow therapeutic range and variable pharmacokinetics; therefore, therapeutic drug monitoring (TDM) is recommended. For this reason, in this study, an easily applicable, fast, selective, accurate, reliable, and economical LC-MS/MS method was developed for the determination of haloperidol in human plasma for use in TDM and also method was validated according to European Medicines Agency (EMA) Bioanalytical method validation guidelines. In the developed method, analyte and internal standard were extracted from plasma by salt-assisted liquid-liquid microextraction (SALLME) technique and after that injected to the LC system. The limit of quantification of haloperidol was determined as 1 ng/ml. The calibration curve was validated between 1-15 ng/ml, with correlation coefficients >0.99. In addition, the developed method was used to determine drug concentration levels in the plasma of real patients.

Sorbents Modified by Deep Eutectic Solvents in Microextraction Techniques

Sorbents Modified by Deep Eutectic Solvents in Microextraction Techniques

Skin emitted volatiles analysis for noninvasive diagnosis: the current advances in sample preparation techniques for biomedical application.

Human skin emits a series of volatile compounds from the skin due to various metabolic processes, microbial activity, and several external factors. Changes in the concentration of skin volatile metabolites indicate many diseases, including diabetes, cancer, and infectious diseases. Researchers focused on skin-emitted compounds to gain insight into the pathophysiology of various diseases. In the case of skin volatolomics research, it is noteworthy that sample preparation, sampling protocol, analytical techniques, and comprehensive validation are important for the successful integration of skin metabolic profiles into regular clinical settings. Solid-phase microextraction techniques and polymer-based active sorbent traps were developed to capture the skin-emitted volatile compounds. The primary advantage of these sample preparation techniques is the ability to efficiently and targetedly capture skin metabolites, thus improving the detection of the biomarkers associated with various diseases. In further research, polydimethyl-based patches were utilized for skin research due to their biocompatibility and thermal stability properties. The microextraction sampling tools coupled with high sensitive Gas Chromatography-Mass Spectrometer provided a potential platform for skin volatolomes, thus emerging as a state-of-the-art analytical technique. Later, technological advancements, including the design of wearable sensors, have enriched skin-based research as it can integrate the information from skin-emitted volatile profiles into a portable platform. However, individual-specific hydration, temperature, and skin conditions can influence variations in skin volatile concentration. Considering the subject-specific skin depth, sampling time standardization, and suitable techniques may improve the skin sampling techniques for the potential discovery of various skin-based marker compounds associated with diseases. Here, we have summarised the current research progress, limitations, and technological advances in skin-based sample preparation techniques for disease diagnosis, monitoring, and personalized healthcare applications.

Green microextraction techniques in therapeutic drug monitoring

Therapeutic drug monitoring (TDM) is crucial for optimizing drug therapy, particularly for medications with narrow therapeutic windows. By measuring drug concentrations in biological fluids, TDM aids in dose individualization, adherence assessment, and the prevention of adverse effects. Recent advancements focus on miniaturized and eco-friendly sample preparation techniques, such as microextraction methods, which are efficient and low-cost. These include liquid- and solid-phase microextraction, offering benefits such as automation and high-throughput performance which have significantly improved TDM efficiency. Additionally, the emergence of microsampling offers a less invasive alternative to traditional blood collection for TDM and pharmacokinetic studies. Coupling these innovations with sensitive analytical techniques, like liquid chromatography-tandem mass spectrometry, enables accurate and reliable drug quantification from minimal sample volumes. These developments collectively enhance the clinical utility of TDM and contribute to improved patient outcomes. This paper provides a comprehensive review of recent advancements in green microextraction techniques as applied to therapeutic drug monitoring.

Single-run gas chromatography-mass spectrometry method for the analysis of phthalates, polycyclic aromatic hydrocarbons, and pesticide residues in infant formula based on dispersive microextraction techniques

For the first time, three important contaminant groups (phthalates, polycyclic aromatic hydrocarbons, and pesticides), traditionally monitored by separated methods, were simultaneously analyzed in complex infant formula matrices. An accurate and sensitive analytical method based on gas chromatography-mass spectrometry (GC–MS) was developed for 45 food contaminants. Dispersive solid-phase extraction and low-density solvent-based dispersive liquid–liquid microextraction techniques were combined for clean-up and analyte enrichment purposes. Distinct GC–MS injection conditions were studied with the highest analytical responses obtained at high temperatures in pulsed splitless mode at high pulse pressures. Low matrix effects were observed for the majority of analytes under study, indicating a possible relation of these effects with the physicochemical parameters of the analytes. Adequate method performance characteristics were achieved, covering limits of detection and quantification sufficiently low to monitor the regulated compounds at the maximum limits fixed for infant formula. Furthermore, the greenness and practicality of the proposed method were evaluated through the AGREE and BAGI metric tools, respectively. In summary, the application of the proposed method to commercial infant formulas, with the identification and quantification of benzo[a]pyrene, benz[a]anthracene, dibutyl phthalate, di(2-ethylhexyl) phthalate, dimethyl phthalate, and diisobutyl phthalate at levels between 1.4 and 47.1 µg kg−1 in a total of 30.0 % samples, demonstrates their suitability for routine analysis as well as contributes to the first data on the co-occurrence of PAHs and phthalates in infant formula.

Human Health Risk Assessment of the Photocatalytic Oxidation of BTEX over TiO2/Volcanic Glass.

This study demonstrates rapid photocatalytic oxidation of a benzene, toluene, ethylbenzene, and xylene (BTEX) mixture over TiO2/volcanic glass. The assessment of the photocatalytic oxidation of BTEX was conducted under conditions simulating those found in indoor environments affected by aromatic hydrocarbon release. We show, under UV-A intensities of 15 mW/cm2 and an air flow rate of 55 m3/h, that low ppmv levels of BTEX concentrations can be reduced to below detectable levels. Solid-phase microextraction technique was employed to monitor the levels of BTEX in the test chamber throughout the photocatalytic oxidation, lasting approximately 21 h. Destruction of BTEX from the gas phase was observed in the following sequence: o-xylene, ethylbenzene, toluene, and benzene. This study identified sequential degradation of BTEX, in combination with the stringent regulatory level set for benzene, resulted in the air quality hazard indexes (Total Hazard Index and Hazard Quotient) remaining relatively high during the process of photocatalytic oxidation. In the practical application of photocatalytic purification, it is crucial to account for the slower oxidation kinetics of benzene. This is of particular importance due to not only its extremely low exposure limits, but also due to the classification of benzene as a Group 1 carcinogenic compound by the International Agency for Research on Cancer (IARC). Our study underscores the importance of taking regulatory considerations into account when using photocatalytic purification technology.

Determination of Volatile Components in Mountain Tea (Sideritis condensata Boiss. Et. Heldr. Apud Bentham) Grown in its Natural and Agricultural Field Environment

In this study, it was aimed to compare the volatile components of Sideritis condensata Boiss. Et. Heldr. Apud Bentham species mountain tea collected from nature and grown under field conditions with HS-SPME GC-MS technique. The cuttings of the plant were collected from Isparta Province, Yenişarbademli District, rocky location of Dedegöl Mountain in April 2020, and were transferred to field conditions at the end of May in the same year after rooted in a greenhouse environment. In June-July 2021, during the flowering period, leaf and flower samples peculiar to the species were collected from both field and natural environments and dried under room conditions. Using solid based micro-extraction technique, 72 volatile components were determined in natural growing environment and 88 volatile components in field envi-ronment in S. condensata by gas chromatography mass spectrometry (GC-MS). Among the volatile com-ponents found in natural habitat and field environment, α-pinene (9.30%-2.32%), β-pinene (18.12%-5.66%), β-ocimene (4.46%-1.06%), trans-caryophyllene (12.77%-0.83%), germacrene-D (10.59%-0.67%), γ-cadinene (2.09%-10.94%), α-gurjunene (0.03%-16.68%), farnesene (0.98%-6.00%) were identified as the main components of Sideritis condensata. When the volatile components were examined, it was obser-ved that sesquiterpene hydrocarbons were high.

IMPLICATIONS OF STABILIZERS USED IN BRINE OF SOFT WHITE CHEESE ON THE AROMA PROFILE OF CHEESES

This paper describes the compositional characterization of cheese brine and aroma profile of Soft White cheese which contains different stabilizers such as sodium caseinate, carrageenan and guar gum in the brine solutions. During the 60-day storage period, pH, titration acidity, dry matter, fat, salt and protein amounts of cheese brines were analyzed. The aroma profile of the cheese samples was examined by gas chromatography–mass spectrometry using a solid-phase microextraction technique and the proportional distribution of volatile compounds was revealed. The stabilizers in the brine increased the dry matter content in the cheese mass by binding the water and reduced salt penetration into the cheese mass. A total of 23 aromatic compounds were identified including 4 aldehydes, 5 alcohols, 4 esters, 1 ether, 5 hydrocarbons, 2 ketones and 2 organic acids in cheeses. Carrageenan and guar gum were found more effective than sodium caseinate in terms of flavor retention.

New biological monitoring method for 1-Naphthol and 2-Naphthol based on stir bar sportive dispersive micro extraction strategy using magnetic ionic liquid

Naphthalene is one of the few volatile bicyclic aromatic hydrocarbons and a white crystalline solid that can sublimate at room temperature. Since 2000, according to the results of animal studies on the carcinogenic effects of naphthalene, this substance has been recognized as a major problem for the environment and industrial environments. Exposure to naphthalene leads to kidney toxicity, hemolytic anemia and other health problems in the human body. The International Agency for Cancer has placed naphthalene in group 2B (probably carcinogenic to humans). 1- naphthol and 2- naphthol are biological urinary indicators of human exposure to naphthalene in work environments. For the first time in this research, the concentration of 1-naphthol and 2-naphthol in urine, which serves as an indicator of naphthalene exposure, was performed through a method known as magnetic ionic liquids-based disperse liquid–liquid microextraction (MIL-DLLME). Subsequently, the samples were analyzed using gas chromatography with a flame ionization detector (GC-FID). Additionally, the factors that influence the extraction of this metabolite, such as the quantity of extracting solvent, speed of mixing, proportion of salt added, duration of mixing, and pH value, were determined using both a two-level factorial test design and a central composite design. Calibration curves were developed under optimal conditions, and the validity of the developed microextraction method was studied with different statistical methods and the analysis of real samples. A strong linear correlation between the subpeak level and the corresponding concentrations was observed in the range of 0.5–0.002 μg/ml for 1-naphthol and 2.00–0.001 µg mL-1for 2-naphthol. In addition, the detection limit and quantitative detection limit for 1-naphthol were 0.0006 µg mL−1, 0.002 µg mL−1, and 0.0003 µg mL−1, 0.001 µg mL-1for 2-naphthol respectively. The MIL-DLLME extraction method can be regarded as an environmentally friendly microextraction technique since it eliminates the need for dispersing solvents and toxic organic solvents as extractants. Results showed that the proposed technique can be applied for biological monitoring of the biomarkers of naphthalene in the exposed workers during occupational or environmental assessments.

Ruthenium nanoparticles encrusted with nitrogen & sulphur magnetic quantum dots as an efficient electrochemical sensor for simultaneous determination of itraconazole and terbinafine; a dual regimen for black fungus: Magnetic solid phase micro-extraction for urine and plasma analysis

After COVID-19 pandemic, Mucormycosis (black fungus) spreads as one of its related complications, due to the decrease in immunity system after administration of COVID-19 treatment drugs. A combination therapy of Itraconazole (ITR) and Terbinafine (TEB) was proved to be effective for treatment of black fungus. A novel electrochemical sensor was designed for estimation of ITR & TEB simultaneously by square wave voltammetric (SWV) technique. The sensor was fabricated using N&S-codoped magnetic quantum dots (N,S-MQDs) and ruthenium nanoparticles (Ru NPs). The fabricated sensor was characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), powder X ray diffraction (pXRD), Fourier transform-Infrared (FT-IR), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). Full optimization study for various experimental and instrumental parameters, in addition to method validation following International conference on Harmonization (ICH) guidelines was achieved. A good linearity in the range of 0.5–30 μg mL−1 with limit of detection (LOD) 0.24 and 0.19 μg mL−1 for ITR and TEB, respectively were obtained. The sensor was applied for analysis of ITR and TEB simultaneously in human plasma and urine samples without any interferences by applying dispersive magnetic solid phase micro-extraction (dMSPE) technique, where excellent recovery results exceeding 95 % were achieved.