An improved fabric phase sorptive extraction method for the determination of five selected antidepressant drug residues in human blood serum prior to high performance liquid chromatography with diode array detection

Adapting Fabric Phase Sorptive Extraction as an Innovative Multitool for Sample Transfer and Extraction in Pharmacokinetic Analysis Followed by LC-MS Determination of Levofloxacin in Plasma Samples

Fabric phase sorptive extraction (FPSE) is a simple microextraction technique that allows analytes to be rescued from matrix components while using a small volume of samples to analyze complex biological systems. This study used FPSE as a microextraction tool and a sample storage and transfer device. Levofloxacin as a model molecule was applied intravenously (IV) to New Zealand male rabbits. The samples were simultaneously extracted by using FPSE and protein precipitation methods. The final solutions were analyzed using LC-MS equipped with an ACE C18 LC Column (150 mm × 4.6 mm, 5 μm) at 25 °C employed in isocratic elution mode using solution A (0.1% formic acid in water)/solution B (0.1% formic acid in acetonitrile) (80:20, v/v). The total analysis time was less than 15 min. The developed method was validated using the ICH M10 bioanalytical method validation and study sample analysis guidelines. The results obtained using FPSE were statistically identical to those obtained using protein precipitation. The plasma samples applied onto FPSE (10 μL onto 1.0 cm × 1.0 cm Biofluid Sampler) were stored in three different temperatures [refrigerator (2-8 °C), at ambient temperature (20 ± 5 °C), and in the stability cabinet (40 °C, 75% humidity)] and three different storage conditions (Eppendorf tubes, plastic containers, and straw paper envelopes). Levofloxacin in plasma samples adsorbed by FPSE biofluid sampler remained stable at 2-8 °C in Eppendorf tubes for at least 1 week. This study showed that FPSE could be used as a sample storage and transfer device for pharmacokinetic applications that need to work with small sample volumes and discard aggressive cold chains to store and transfer the plasma samples.

Utilization of a pH-switchable hydrophilicity solvent for the microextraction of clomipramine from human urine samples

Clomipramine (CLP) is a tricyclic antidepressant drug, and its determination in biological samples is of high importance in clinical and forensic evaluations to assure appropriate drug concentrations. In the present study, benzoic acid was employed as a pH-switchable hydrophilicity solvent (SHS) for the microextraction of CLP from authentic human urine samples prior to its determination by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The microextraction protocol was based on the phase transition of the SHS through pH alteration that resulted in its rapid dispersion and simultaneous phase separation. The obtained solid was collected in a syringe filter, dissolved in methanol, and analyzed. The main parameters that affected the efficiency of the microextraction procedure were studied and optimized to ensure high extraction efficiency for CLP and the analytical method was validated. Under optimum conditions, good linearity was observed between 0.05 and 5.0 μg mL-1. The limit of detection and limit of quantification were found to be 0.015 and 0.05 μg mL-1, respectively. The RSD values for intra-day repeatability and inter-day precision were 2.4-8.9 % and 1.7-9.1 %, respectively. The relative recovery values were within 90.0 and 110.0 % in all cases, demonstrating good method accuracy. The proposed SHS microextraction showed cost-efficiency, handling simplicity, and rapidity resulting in enhanced sample throughput. Moreover, the proposed method exhibited a green character and good applicability based on its evaluation by Green Analytical Procedure Index and Blue Applicability Grade Index.

Quantification of mirtazapine in tablets via DNA binding mechanism; development of a new HPLC method

Atypical antidepressant mirtazapine (MIR) is mostly prescribed for the management of major depressive disorder. The identification of MIR in pharmaceutical dosage forms was made possible by developing a novel, quick, sensitive high-performance liquid chromatography (HPLC) approach that was verified in accordance with ICH recommendations. In the first part of this study, HPLC investigations were optimized with regard to variables including pH, working column, mobile phase, temperature, and flow rate. The limit of detection (LOD) was 0.013 ppm, the limit of quantification (LOQ) was 0.044 ppm, and the linear range was computed as 0.5-15 ppm (R2 = 0.9998). The recovery investigation assessed the method's accuracy, which was shown to range between 98.82 and 100.97 %. In the second part, by using UV-vis spectroscopy, HPLC, thermal denaturation, and viscosity measurements, the mechanism of binding interaction of MIR with double-stranded fish sperm deoxyribonucleic acid (dsDNA) has been thoroughly studied. The DNA binding constants (Kb) were determined using UV-Vis absorption and HPLC methods. To investigate the interactions of MIR with dsDNA, molecular docking calculations and additionally, molecular dynamics simulations were performed. Results showed that MIR is located in the minor groove of dsDNA, and in addition to hydrogen bonding, electrostatic interaction is also formed between the aromatic ring of MIR and phosphate oxygen of dsDNA. Finally, a binding characterization study using MIR tablets was also conducted in order to assess the interaction mechanism of the DNA with the drug using the validated analytical procedure developed for the MIR molecule.

Novel Sorptive Sample Preparation Techniques for Separation Science

The primary analytical challenge is to selectively extract the target analytes using a suitable sample preparation technique and introduce them into the downstream analytical instrument. The critical step in the chemical analysis is sample preparation. Sorptive sample preparation techniques are among the new generation of microextraction approaches, and are compliant with green analytical chemistry principles. A recent intercontinental collaboration between two academic research laboratories—the Aristotle University of Thessaloniki, Greece, and the Florida International University, USA—has yielded a significant number of analytical/bioanalytical methods using fabric phase sorptive extraction (FPSE), magnet integrated fabric phase sorptive extraction (MI-FPSE), and capsule phase microextraction (CPME) for the isolation of various analytes from different complex sample matrices. A brief description of these techniques with regards to principle, synthesis, applications, and advantages and disadvantages along with paradigms is presented.

Recent Advances in Analytical Techniques for Antidepressants Determination in Complex Biological Matrices: A Review

Depression is one of the most prevalent but severe of mental disorders, affecting thousands of individuals across the globe. Depression, in its most extreme form, may result in self-harm and an increased likelihood of suicide. Antidepressant drugs are first-line medications to treat mental disorders. Unfortunately, these medications are also prescribed for other in- and off-label conditions, such as deficit/hyperactivity disorders, attention disorders, migraine, smoking cessation, eating disorders, fibromyalgia, pain, and insomnia. This results in an increase in the use of antidepressant medications, leading to clinical and forensic overdose cases that could be either accidental or deliberate. The findings revealed that people who used antidepressants had a 33% greater chance of dying sooner than expected, compared to those who did not take the medications. Analytical techniques for precisely identifying and detecting antidepressants and their metabolic products in a variety of biological matrices are greatly needed to be developed and made available. Hence, this study attempts to discuss various analytical techniques used to identify and determine antidepressants in various biological matrices, which include urine, blood, oral fluid (saliva), and tissues, which are commonly encountered in clinical and forensic science laboratories.

Green bioanalysis: an innovative and eco-friendly approach for analyzing drugs in biological matrices

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.

Influence of Chromatographic Conditions on LOD and LOQ of Fluoxetine and Sertraline Analyzed by TLC-Densitometric Method

This research introduces the analysis of fluoxetine and sertraline by means of the TLC-densitometric method. They provide information on LOD and LOQ under various chromatographic conditions. The study used adsorption (NPTLC) and partition (RPTLC) thin-layer chromatography in combination with a densitometric analysis. Four types of chromatographic plates precoated with: silica gel 60 F254, silica gel 60, silanized silica gel 60 F254 (RP-2), and a mixture of silica gel 60 and kieselguhr F254, as well as three mobile phases: chloroform + methanol + ammonia (9:1:0.4, v/v/v), chloroform + methanol + glacial acetic acid (5:4:1, v/v/v), and acetone + toluene + ammonia (10:9:1, v/v/v), were used in NPTLC. RP-18F254 and silanized silica gel 60 F254 (RP-2) plates and four mobile phases: methanol + water (10:0 and 9:1, v/v), acetone + water (10:0 and 9:1, v/v), were used in RPTLC. The lowest LOD and LOQ values for fluoxetine were obtained using a silanized silica gel 60 F254 (RP-2) with acetone + toluene + ammonia (10:9:1, v/v/v) in NPTLC, and with a silanized silica gel 60 F254 (RP-2) in combination with methanol + water (10:0, v/v) in RPTLC. The lowest LOD and LOQ values of sertraline were obtained using a silica gel 60 with acetone + toluene + ammonia (10:9:1; v/v/v) in NPTLC. The smallest amount of sertraline was detected on the silanized silica gel 60 F254 plate in combination with methanol + water (9:1, v/v) in RPTLC. The obtained results provide important information that can give a good basis and set the direction for further, more detailed research; the results can also benefit other researchers who analyze fluoxetine and sertraline with the TLC technique in model systems (testing standards) as well as in drug and biological samples.

Fabric Phase Sorptive Extraction for the Determination of Anthracyclines in Sewage

Anthracyclines are a group of antineoplastic compounds used to treat acute leukemia and other cancers, and they are excreted after consumption by patients. These chemicals are often found in sewage at very low concentration levels. For this reason, the development of sensitive analytical methodologies capable of determining them at low concentrations is of prime importance. A simple, fast and sensitive analytical method using fabric phase sorptive extraction (FPSE) followed by ultra-high performance liquid chromatography with fluorescence detection (UHPLC-FD) has been developed and validated for the extraction of anthracyclines from sewage samples. FPSE is a green, cheap, simple, selective and rapid sample preparation technique. The different parameters that affect the performance of the FPSE process, including extraction time, eluting solvent, elution time and pH, were optimized. The developed method showed satisfactory reproducibility, with intraday and interday RSD values lower than 15% for all the compounds and limits of detection between 0.1–0.15 µg·L−1. The unique combination of sample preparation by this micro-extraction technique with fluorescence detector have resulted in the satisfactory extraction of highly polar anthracyclines, without any noticeable matrix effect, a very common shortcoming of exhaustive sample preparation technique such as solid phase extraction (SPE) and mass spectrometry.

Matrix compatibility of typical sol-gel solid-phase microextraction coatings in undiluted plasma and whole blood for the analysis of phthalic acid esters

Sol-gel materials have been widely used for solid-phase microextraction (SPME) coatings due to their outstanding performance; in contrast, sol-gel SPME coatings have seldom been used for in vivo sampling. The main reason is that their matrix compatibility is unclear. In order to promote the application of this type of coating and accelerate the development of in vivo SPME, in this study, the matrix compatibility of several typical sol-gel coatings was assessed in plasma and whole blood using phthalic acid esters as analytes. The service life of five kinds of sol-gel coatings was among 20-35 times in undiluted plasma, while it was 27 times for a homemade commercial polydimethylsiloxane coating, which indicates good matrix compatibility of sol-gel coatings in untreated plasma. The sol-gel hydroxy-terminated silicone oil/methacrylic acid fiber achieved the highest extraction ability among all of the fibers, and it was tested in pig whole blood. It could be continuously used for at least 22 times, demonstrating good potential for in vivo sampling. Subsequently, a direct-immersion SPME/gas chromatography-flame ionization detection method was established for the determination of 5 phthalic acid esters in blood. Compared with other methods reported in the literature, this method is rapid, simple, sensitive, and accurate, and does not need expensive instruments or tedious procedures. A simulation system of animal blood circulation was constructed to verify the practicability of sol-gel SPME coatings in animal vein sampling. The result illustrated the feasibility of that coating for in vivo blood sampling, but a more accurate quantification calibration approach needs to be explored.

New Method for the Monitoring of Antidepressants in Oral Fluid Using Dried Spot Sampling

The increase in the consumption of antidepressants is a public health problem worldwide, as these are a class of compounds widely used in the treatment of several illnesses, such as depression and anxiety. This work aimed to develop and optimize a method for the quantification of a number of antidepressants and their metabolites (fluoxetine, venlafaxine, O-desmethylvenlafaxine, citalopram, sertraline, and paroxetine) in 100 µL of oral fluid using the dried saliva spots (DSS) sampling approach and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The method was validated, presenting linearity within the studied range, with detection and quantification limits ranging between 10 and 100 ng/mL, and coefficients of determination (R²) of at least 0.99 for all analytes. Recoveries were between approximately 13 and 46%. The analysis of precision and accuracy presented acceptable coefficients of variation and relative errors, considering the criteria usually accepted in the validation of bioanalytical procedures. The method herein described is the first to be reported using DSS for the extraction of antidepressants, proving to be a sensitive, simple, and fast alternative to conventional techniques, and capable of being routinely applied in clinical and forensic toxicology scenarios.

Exploring sol-gel zwitterionic fabric phase sorptive extraction sorbent as a new multi-mode platform for the extraction and preconcentration of triazine herbicides from juice samples

Triazine herbicides are a class of common pesticides which are widely used to control the weeds in many agricultural crops. Although many studies have described methodologies for the determination of triazine herbicides in aqueous samples, the attention given to agricultural crops and their products is far more limited. In this study, a novel sol-gel zwitterionic multi-mode fabric phase sorptive extraction (FPSE) platform was developed for the matrix clean-up, extraction and preconcentration of five triazine herbicides from fruit juice samples prior to their determination by high performance liquid chromatography-diode array detection (HPLC-DAD). The novel zwitterionic multi-mode sorbent was characterized and its performance for fruit juice analysis was evaluated. Compared to other sol-gel sorbents, the novel zwitterionic sorbent helped cleaning all the acidic interferences from fruit juices. The herein reported FPSE protocol was optimized and validated. Under optimum conditions, the FPSE method showed good accuracy, precision and sensitivity. The limits of detection and limits of quantification for all analytes were 0.15 ng mL^-1 and 0.50 ng mL^-1, respectively. The enhancement factors of this method ranged between 36.7 and 51.8. The relative standard deviation for intra-day precision was below 5.6% and for inter-day precision was below 8.8%. Finally, the proposed FPSE-HPLC-DAD method was successfully employed for the analysis of various fruit juice samples.

Nanoplatform-Integrated Miniaturized Solid-Phase Extraction Techniques: A Critical Review

Preparation of the biological samples is one of the most critical steps in sample analysis. In past decades, the liquid-liquid extraction technique has been used to extract the desired analytes from complex biological matrices. However, solid-phase extraction (SPE) gained popularity due to versatility, simplicity, selectivity, reproducibility, high sample recovery %, solvent economy, and time-saving nature. The superior extraction efficiency of SPE can be attributed to the development of advanced techniques, including the nanosorbents technology. The nanosorbent technology significantly simplified the sample preparation, improved the selectivity, diversified the application, and accelerated the sample analysis. This review critically expands on the to-date advancements reported in SPE with particular regards to the nanosorbent technology.

Recent advances in the extraction of triazine herbicides from water samples

Pesticides are excessively used in agriculture to improve the quality of crops by eliminating the negative effects of pests. Among the different groups of pesticides, triazine pesticides are a group of compounds that contain a substituted C₃ H₃ N₃ heterocyclic ring, and they are widely used. Triazine pesticides can be dangerous for humans as well as for the aquatic environment because of their high toxicity and endocrine disrupting effect. However, the concentration of these chemical compounds in water samples is low. Moreover, other compounds that may exist in the water samples can interfere with the determination of triazine pesticides. As a result, it is important to develop sample preparation methods that provide preconcentration of the target analyte and sufficient clean-up of the samples. Recently, a wide variety of novel microextraction and miniaturized extraction techniques (e.g., solid-phase microextraction and liquid-phase microextraction, stir bar sorptive extraction, fabric phase sorptive extraction, dispersive solid-phase extraction, and magnetic solid-phase extraction) have been developed. In this review, we aim to discuss the recent advances regarding the extraction of triazine pesticides from environmental water samples. Emphasis will be given to novel sample preparation methods and novel sorbents developed for sorbent-based extraction techniques.

Green Bioanalytical Applications of Graphene Oxide for the Extraction of Small Organic Molecules

Bioanalysis is the scientific field of the quantitative determination of xenobiotics (e.g., drugs and their metabolites) and biotics (e.g., macromolecules) in biological matrices. The most common samples in bioanalysis include blood (i.e., serum, plasma and whole blood) and urine. However, the analysis of alternative biosamples, such as hair and nails are gaining more and more attention. The main limitations for the determination of small organic compounds in biological samples is their low concentration in these matrices, in combination with the sample complexity. Therefore, a sample preparation/analyte preconcentration step is typically required. Currently, the development of novel microextraction and miniaturized extraction techniques, as well as novel adsorbents for the analysis of biosamples, in compliance with the requirements of Green Analytical Chemistry, is in the forefront of research in analytical chemistry. Graphene oxide (GO) is undoubtedly a powerful adsorbent for sample preparation that has been successfully coupled with a plethora of green extraction techniques. GO is composed of carbon atoms in a sp² single-atom layer of a hybrid connection, and it exhibits high surface area, as well as good mechanical and thermal stability. In this review, we aim to discuss the applications of GO and functionalized GO derivatives in microextraction and miniaturized extraction techniques for the determination of small organic molecules in biological samples.

Green bioanalytical sample preparation: fabric phase sorptive extraction

Fabric phase sorptive extraction (FPSE) is a recently introduced sample preparation technique that has attracted substantial interest of the scientific community dealing with bioanalysis. This technique is based on a permeable and flexible substrate made of fabric, coated with a sol-gel organic-inorganic sorbent. Among the benefits of FPSE are its tunable selectivity, adjustable porosity, minimized sample preparation workflow, substantially reduced organic solvent consumption, rapid extraction kinetics and superior extraction efficiency, many of which are well-known criteria for Green Analytical Chemistry. As such, FPSE has established itself as a leading green sample preparation technology of 21st century. In this review, we discuss the principal steps for the development of an FPSE method, the main method optimization strategies, as well as the applications of FPSE in bioanalysis for the extraction of a wide range of analytes (e.g., estrogens, benzodiazepines, androgens and progestogens, penicillins, anti-inflammatory drugs, parabens etc.).

Fan-based device for integrated air sampling and microextraction

In this article, a new air sampler based on a conventional computer fan is presented and evaluated. The fan has a double role as it acts as the air pumping system and supports the sorptive phases, which are located on its blades. The compact design and the reduced energy consumption (it can operate with a standard cell phone charger) confers high portability to the device. Also, a simple alternative integrated into the fan is proposed for using an internal standard during the sampling, thus increasing the precision of the measurements. In this first communication, sol-gel Carbowax 20 M coated fabric phases are used as sorptive membranes thanks to their planar geometry, mechanical and thermal stability, and their versatility covering different interaction chemistries. After sampling, the fabric phases are placed in a headspace vial, which is finally analyzed by gas chromatography-mass spectrometry. The sampler has been characterized for the extraction of selected volatile organic compounds (chloroform, benzaldehyde, toluene, and cyclohexane) from air and its versatility has also been evaluated by the identification of semi-volatile compounds in working place (toluene and xylene in laboratory residue storage room) and biogenic volatile compounds in natural samples (terpenes in fresh pine needles and orange peel samples).

Fine-tuning pharmacological properties of mirtazapine antidepressant drug: a theoretical study

It has become obvious that fluorinated drugs have a significant role in medicinal applications. In this study, the fluorination of mirtazapine antidepressant drug was investigated using density functional theory calculations. We found that the intramolecular hydrogen bonding and charge transfers of the mirtazapine drug were influenced by fluorine substitution. Our results also reveal that the fluorination altered the stability, solubility, and molecular polarity of the mirtazapine antidepressant drug. Moreover, our results show that the electronic spectra of fluorinated derivatives of the mirtazapine exhibit a red shift toward higher wavelengths compared to the original antidepressant drug. Our calculations show that the difference between G value of the gas and water (ΔG) of fluorinated derivatives of the mirtazapine drug was negative. We also found that the fluorination can increases the first hyperpolarizability of the mirtazapine antidepressant drug. Our results present an efficient strategy to improve the nonlinear optical responses of the antidepressant drugs. Consequently, the results of present study show that the fluorination of mirtazapine could be considered as a promising strategy to design antidepressant drugs with better pharmacological properties.Communicated by Ramaswamy H. Sarma.

Two-phase agarose gel-electromembrane extraction: Effect of organic solvent as an acceptor phase in electroendosmosis flow phenomenon

In this study, a new mode of gel electromembrane extraction (G-EME) namely as "Two-phase G-EME", is suggested for the sensitive quantification of five basic drugs (desipramine, clomipramine, trimipramine, citalopram and clozapine) in biological samples. Compared to classical G-EME which is based on aqueous-gel-aqueous layout, herein, the aqueous acceptor phase (AP) was replaced with organic solvent. Briefly, negative electrode was immersed into the organic AP (with low conductivity) and positive electrode into the aqueous donor phase (DP). Based on our results, this simple adjustment significantly reduced electroendosmosis (EEO) flow phenomenon which is considered as the main issue in G-EME. In the workflow, target analytes were extracted from the 7.0 mL sample, across the fabricated agarose gel membrane, to the 100 μL of the AP under the optimized extraction conditions (organic solvent type: acetonitrile; pH of gel membrane: 5.0, pH of sample solution: 4.0, voltage: 45 V and extraction time: 22 min). Then, the organic AP with analytes was analyzed by gas chromatography (GC) instrument with flame-ionization detector (FID). The methodology offered limits of detection (LODs) and recoveries in the range of 1.0-1.5 ng mL^-1 and 48.5-89.0 %, respectively. Finally, we note that two-phase G-EME assembly was able to extract analytes-of-interest in the convenient and safe manner from the hazardous and difficult-to-process biological specimens such as human serum and urine.

Investigating the Utility of Fabric Phase Sorptive Extraction and HPLC-UV-Vis/DAD to Determine Antidepressant Drugs in Environmental Aqueous Samples

Depression is considered to be one of the most prevalent mental disorders in humans. Antidepressant drugs are released in large concentrations and cause adverse effects on the environment and/or human health. Fabric Phase Sorptive Extraction (FPSE), a contemporary solid sorbent-handling technique, is a quick, sensitive, and simple analytical process. This paper describes a micro-extraction FPSE procedure coupled with High-Performance Liquid-Chromatography–Photodiode Array Detection (FPSE-HPLC–DAD) for the simultaneous extraction and analysis of five antidepressants, namely citalopram, clozapine, mirtazapine, bupropion and sertraline. Three fabric media (Whatman Cellulose filter, Whatman Microfiber Glass filter and Polylactic acid disks) and two different sol–gel sorbents (polyethylene glycol (PEG 300), alongside poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG 5.800)) were tested. The best FPSE device was observed to be the microfiber glass filter coated with PEG 300 sol–gel sorbent. In addition, the parameters that affect the efficiency of the process (FPSE media and sorbents, sample pH, extraction time, elution time, etc.) were optimized. The proposed methodology displays a linear range with absolute recovery values higher than 60%, RSD% of less than 13% and LOQs in the range between 1.9–10.7 μg·L−1. Finally, the method was applied in hospital and urban effluents and lake water samples, but none of the analytes were detected.