Search Results (670)

(1) Background: The concentration of lamotrigine, an antiepileptic drug very often used in bipolar disorder, is most often determined in the blood, with many inconveniences. An alternative may be to use saliva as a diagnostic material for this purpose. The development of a method to determine lamotrigine in saliva as a biological material significantly improves patient comfort during sampling. The developed method uses solid-phase extraction for the isolation of the drug from saliva for the first time. (2) Methods: This study aimed to develop a method to determine lamotrigine in saliva using solid-phase extraction (SPE) for isolation and liquid chromatography with a diode array detector (LC-DAD) for quantitative analysis. (3) Results: The method was validated by determining its linearity in the concentration range 10–2000 ng/mL (R² > 0.99), and the intra- and inter-day precision expressed as coefficient of variation (CV%) did not exceed 15%. (4) Conclusions: The developed method was used to determine the salivary concentration of lamotrigine in patients treated with the studied compound, confirming its usefulness in bipolar disorder (BD). Full article

Limonium gmelini (Willd.) Kuntze, a plant widely used in traditional medicine, has garnered increasing attention for its diverse pharmacological activities, including anti-inflammatory, hepatoprotective, antioxidant, and antimicrobial effects. This study aimed to explore the chemical composition and biological activities of polysaccharides and polyphenolic compounds extracted from both the roots and aboveground parts of Limonium gmelini. Several methods of extraction, including ultrasound-assisted extraction (UAE), conventional maceration (CM), and supercritical fluid extraction (SFE), were employed to obtain bioactive fractions. Chemical profiling, primarily represented by monosaccharides and polyphenolic compounds, was characterized and analyzed using proton nuclear magnetic resonance spectroscopy (¹H-NMR) and gas chromatography-mass spectrometry (GC-MS) techniques. While polyphenol-rich fractions exhibited significant antibacterial activity, particularly against Staphylococcus epidermidis, polysaccharide-rich aqueous fractions showed minimal antibacterial activity. Among the methods, CM and UAE yielded higher polyphenol content, whereas SFE provided more selective extractions. Notably, methanolic SPE fractions derived from the roots were especially enriched in active polyphenols such as gallic acid, myricetin, and naringenin, and they exhibited the highest antibacterial activity against Staphylococcus epidermidis. In contrast, extracts from the aboveground parts showed more moderate activity and a partially different chemical profile. These findings underscore the importance of plant part selection and support the targeted use of root-derived polyphenol-enriched fractions from L. gmelini as promising candidates for the development of natural antibacterial agents. Further investigation is needed to isolate and validate the most active constituents for potential therapeutic applications. 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

To enhance the signal intensity of kynurenines, which are present at trace concentrations in biological fluids, a novel analytical approach was developed, combining pressure-assisted electrokinetic injection (PAEKI) with a mixed micelle system based on sodium dodecyl sulfate (SDS) and Brij-35. The method was applied to key compounds of the kynurenine pathway, including L-tryptophan, kynurenine, 3-hydroxykynurenine, and kynurenic acid, as well as to the aromatic amino acids (AAs) L-tyrosine and L-phenylalanine. PAEKI was performed by electrokinetic injection for 2 min at −6.5 kV (reversed polarity) and 0.5 psi (3.45 kPa) using a fused silica capillary (50 cm in length, 50 µm inner diameter). The background electrolyte (BGE) consisted of 20 mM Na₂B₄O₇ (pH 9.2), 2 mM Brij-35, 20 mM SDS, and 20% (v/v) methanol (MeOH). The limit of detection (LOD) using a diode array detector (DAD) was 1.2 ng/mL for kynurenine and ranged from 1.5 to 3.0 ng/mL for the other analytes. The application of PAEKI in conjunction with micellar electrokinetic capillary chromatography (MEKC) and solid-phase extraction (SPE) of artificial urine samples resulted in a 146-fold increase in signal intensity for kynurenines compared to that observed using the hydrodynamic injection (HDI) mode. The developed method demonstrates strong potential for determining kynurenine pathway metabolites in complex biological matrices. Full article

Heterozygous mutations in the GBA1 gene, encoding the enzyme glucocerebrosidase (GCase), are major risk factors for Parkinson’s Disease (PD). Ambroxol, a small chaperone originally used as a mucolytic agent, has been shown to cross the blood–brain barrier, enhance GCase activity, and reduce α-synuclein levels, making it a promising therapeutic candidate for disease-modifying effects in GBA1-associated PD (GBA1-PD). This study aimed to develop a method to quantify ambroxol levels in human plasma and cerebrospinal fluid (CSF) using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Ambroxol was determined by online solid-phase extraction (SPE), coupled with LC-MS/MS, by gradient elution on a monolithic column. Detection employed a 3200 QTRAP tandem mass spectrometer in the positive electrospray ionization mode. Calibration curves exhibited linearity across the analyzed ranges in both plasma and CSF. The recovery rate ranged from 106.7% to 113.5% in plasma and from 99.0% to 103.0% in CSF. No significant matrix effect was observed. Intra-day and inter-day precisions were below 11.8% in both matrices, and accuracy ranged from 89.9% to 103.1% in plasma and from 96.3% to 107.8% in CSF. We evaluated and confirmed the stability of the analyte in plasma and CSF across various storage conditions. The method was successfully validated according to European Medicine Agency (EMA) guidelines and its applicability was confirmed in the context of a multicenter, randomized, double-blind, placebo-controlled, phase II study, designed to monitor the ambroxol levels in the plasma and CSF of GBA1-PD. Full article

This study investigates the presence of mycotoxins in green coffee-based dietary supplements to ensure their safety, given the potential risks of contamination and the growing interest in them among consumers. A sample treatment based on a salting-out assisted liquid–liquid extraction (SALLE) followed by one-step solid-phase extraction (SPE) was selected for the extraction and clean-up of 15 mycotoxins followed by ultra-high performance chromatography–tandem mass spectrometry detection (UHPLC-MS/MS). The target mycotoxins included aflatoxins (AFG1, AFG2, AFB1, AFB2), Alternaria toxins (AOH, AME, TEN), ochratoxin A (OTA), fumonisins (FB1, FB2), zearalenone (ZEN), trichothecenes (T-2, HT-2), enniatin B1 (ENNB1), and beauvericin (BEA). The proposed method was successfully characterized, obtaining high recoveries, a satisfactory precision, and low detection limits. Subsequently, the method was applied for the analysis of 16 commercial food supplements. The analysis revealed the presence of mycotoxins in all samples investigated with Fusarium mycotoxins as the most prevalent. The dietary exposure and risk characterization revealed a low level of risk, except for AFs where chronic exposure in adults may lead to potential health concerns. Full article

Alcohol abuse is a widespread addiction globally, leading to long-term health issues and social consequences. Ethyl glucuronide (EtG) and ethyl palmitate (EtPa) are frequently requested by local authorities, solicitors, or private individuals to assess long-term chronic excessive alcohol consumption. In this paper, we present a validation process aimed at developing sensitive methods for detecting EtG and EtPa in hair samples. EtG was extracted by overnight sonication in water followed by sample clean-up using solid phase extraction (SPE) and analysis by liquid chromatography–tandem mass spectrometry (LC-MS/MS). EtPa was extracted using a simple ultrasonication extraction followed by analysis using gas chromatography–tandem mass spectrometry (GC-MS/MS). The analytical method was validated by assessing linearity, precision, accuracy, recovery, sensitivity, and selectivity. Both EtG and EtPa methods obtained a coefficient of determination (r2) above 0.999 across concentration ranges of 4, 8, 16, 24, 48, and 96 pg/mg and 120, 240, 360, 480, 600, and 720 pg/mg. Extraction recoveries were both close to 100% with stable retention times and proven sensitivity and selectivity. These methods were validated according to the standards set by the United Kingdom Accreditation Service (UKAS) Lab51 and ISO 17025. Full article

The work aimed to investigate the presence of pharmaceutical compounds from the anti-inflammatory class in seawater from the Romanian Black Sea coast and to assess the ecological risk of these substances on the most sensitive organisms. Using the solid-phase extraction technique (SPE) followed by liquid chromatography separation and mass spectrometry detection (LC-MS/MS) of the compounds, the concentrations of these contaminants in selected seawater samples were determined. Ibuprofen was the most commonly detected compound with a frequency of 42.9%, followed by ketoprofen at 31.0.%, diclofenac at 23.8%, and naproxen at 21.4%. The maximum concentrations of pharmaceutical products varied between 13.4 ng/L ketoprofen and 13,575 ng/L caffeine. The order of decreasing maximum concentrations of pharmaceutical compounds in the water of the Black Sea was CAF > IBU > NAP > DIC > KET. The dominant and ubiquitous compound that was determined with the maximum concentration values was caffeine. Strong correlations were observed between three compounds (naproxen: diclofenac, diclofenac: ketoprofen) suggesting the same pollution source. Through the ecological risk assessment, it was observed that both caffeine and ibuprofen can generate high ecological risks for some echinoderms, crustaceans, and fish. Full article

In this study, weekly grab samples extracted by solid-phase extraction (SPE) and stir bar sorptive extraction (SBSE) were compared for the analysis of 230 pesticides in surface waters. Samples were collected from three different locations around Melbourne, Australia. Analysis was performed using Gas Chromatography Quadrupole Time of Flight High Resolution Mass Spectrometry (GC-QToF-HRMS). The two extraction techniques were compared, among others, for their limits of detection, recovery, extraction, and quantification efficiency of pesticides, as well as spatial and temporal differences in detected compounds. The target compounds screened were pesticides belonging mainly to the categories of fungicides, insecticides, and herbicides. Although SBSE extracted more pesticides at two out of three sites, SPE extracted total concentrations up to four times higher than SBSE over all sampling sites. The log K_OW of detected pesticides only partially explained the differences in detection, with SBSE performing better in the absorption of hydrophobic compounds. In addition, matrix effects, in particular turbidity, appeared to hinder extraction of contaminants, especially for SBSE. Spatially, SBSE detected 10 pesticides more than SPE at two locations, while the opposite was true at the third location, where turbidity was higher. The types of pesticides detected varied slightly between techniques and locations. The study highlights the complementarity of SBSE and SPE for monitoring pesticides in natural environments. SBSE is an easy-to-use technique and allows for extraction of a higher number of pesticides at trace level, but it might not be the preferred option for highly turbid waters. SPE requires more tedious and complex sample processing but allows for a more accurate quantification of a broader range of pesticides. 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

A simple, fast, and low-cost pre-concentration methodology based on the application of multi-template molecularly imprinted polymers (mt-MIP) in a solid-phase extraction system coupled with capillary electrophoresis was developed for the determination of naproxen, diclofenac, and ibuprofen in environmental water samples. A systematic study of the mt-MIP composition was conducted using a second-order simplex lattice experiment design (fraction of the functional monomer methacrylic acid (MAA), the total moles of functional monomers, and the total moles of the cross-linker agent). The optimal mt-MIP, consisting of 0.025 mmol of each analyte, with 2.40 mmol of methacrylic acid (MAA) and 3.60 mmol of 4-vinylpyridine (4VP) and 23.00 mmol of the cross-linker agent (EGDMA), was coupled to an SPE system under the optimal conditions: pH = 3.5; 20 mg of mt-MIP; and an eluent (MeOH/NaOH [0.001]). This methodology provides limits of detection from 3.00 to 12.00 µg L⁻¹ for the studied NSAIDs. The methodology’s precision was evaluated in terms of inter- and intra-day repeatability, with %RSD < 10% in all cases. Finally, the proposed method can be successfully applied in the analysis of environmental water samples (bottle, tap, cistern, well, and river water samples), which demonstrates the developed method’s robustness. Full article

Albendazole is an anthelmintic drug commonly used in animals and humans against nematodes. A sensitive, accurate, precise, and time-saving high-performance liquid chromatography (HPLC) method for the simultaneous determination of albendazole and metabolites (albendazole sulfoxide and albendazole sulfone) in cattle plasma has been developed and validated. A solid-phase extraction (SPE) was carried out. Separation was performed with an XBridge^® C18 column (4.6 mm × 250 mm, 5 µm) with gradient elution of acetonitrile:ammonium acetate buffer 0.025 M with pH adjusted to 6.6. The flow rate was 1.2 mL/min, and the PDA detector was set at 292 nm. Calibration curves were linear in the range from 0.025 to 2.0 µg/mL for the three compounds evaluated, with correlation coefficients ≥ 0.99. For the lower limit of quantification (LLOQ), within- and between-run precision and accuracy were satisfactory, with coefficients of variation (CV) ≤ 15.1% and deviations ≤ 117.7%, respectively. The method fulfilled all validation criteria established by the European Medicines Agency guideline (EMA/CHMP/ICH/172948/2019). Full article

Fluorescent brighteners (FBs) are a class of chemicals extensively used in industrial and consumer products. Their environmental occurrences and potential health risks have raised significant concerns. However, the lack of analytical methods for FBs in human samples has hindered the accurate assessment of internal exposure levels. Addressing this gap, this study developed and validated a novel method for the simultaneous determination of 13 FBs at trace levels in human plasma using solid-phase extraction combined with HPLC-MS/MS. The method employed EMR-Lipid SPE columns, which can selectively adsorb phospholipids for plasma sample pre-treatment. Detection was achieved through positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) modes. The results showed that all 13 FBs exhibited good linearity within their respective ranges, with correlation coefficients (R²) greater than 0.992. The method quantitation limits (MQLs) of the FBs ranged from 0.012 to 0.348 ng/mL, and the spiked recovery rates ranged from 61% to 98%. The method was successfully applied to analyze 10 adult plasma samples, detecting 10 FBs with total concentrations ranging from 0.221 to 0.684 ng/mL. This study provides a reliable analytical method for determining FBs in human plasma, providing a basis for further research on human internal exposure to FBs and associated health risk assessments. Full article

Atopic dermatitis (AD), a chronic inflammatory skin condition, is a common allergic disorder. The human skin, the largest organ, serves as the first barrier in protecting the body against various external threats. Human epidermal keratinocytes (HEKs) in the epidermal layer and human dermal fibroblasts (HDFs) in the dermis of the skin are implicated in AD-associated skin inflammation through the secretion of diverse inflammatory mediators, including chemokines. Sigesbeckia pubescens Makino (SP), a traditional Korean and Chinese herbal remedy, is used for treating inflammatory conditions. While several pharmacological effects of SP extract (SPE) have been documented, its specific inhibitory effect on AD-related skin inflammation remains unexplored. Hence, oral administration of SPE to NC/Nga mice reduced the severity of house dust mite extract-induced dermatitis, accompanied by lowered levels of serum inflammatory mediators, decreased epidermal thickness, reduced mast cell infiltration, and restoration of skin barrier function within skin lesions. In conclusion, SPE has demonstrated the ability to alleviate skin inflammation and protect the skin barrier and shows potential as a therapeutic option for AD. SPE inhibited proinflammatory chemokine production by modulating the Janus kinase (JAK) 2/signal transducer and activator of transcription proteins (STAT) 1/STAT3 signaling pathway in IFN-γ- and TNF-α-stimulated skin cells. Full article

During domestic grilling, polycyclic aromatic hydrocarbons (PAHs), which include genotoxic and carcinogenic compounds, can be produced as a result of fat pyrolysis, leakage of cellular juices onto the heat source, and incomplete combustion of fuel. This study aimed to assess the formation of PAHs in pork neck cooked using two different grilling methods (traditional flat grill with beech charcoal and asado grill with beech wood flame) under controlled conditions, with cooking stopping at a core temperature of 72 °C. The impact of marinating and cooking speed (fast or slow) was also evaluated over three cooking sessions. After grilling, the meat samples underwent microwave-assisted extraction, purification through solid-phase extraction (SPE), and analysis using ultra-high-performance liquid chromatography (UHPLC) with spectrofluorometric detection. Statistical analysis was performed using ANOVA (R software, version 4.3.0). None of the samples exceeded the legal limits for benzo[a]pyrene (BaP) and PAH4 (sum of chrysene, benzo[a]anthracene, BaP, and benzo[b]fluoranthene). However, the asado grill showed a significantly higher average PAH contamination (1.21 µg/kg of BaP and 3.92 µg/kg of PAH4) compared with the traditional grill (0.22 µg/kg of BaP and 1.71 µg/kg of PAH4). Marinating and cooking speed did not have a significant impact on PAH levels. Full article