Designing an "all-in-one" microextraction capsule device for the liquid chromatographic-fluorescence determination of doxorubicin and its metabolites in rat plasma

Hierarchically spherical assembly of carbon nanorods derived from metal-organic framework as solid-phase microextraction coating for nitrated polycyclic aromatic hydrocarbon analysis

Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) are pervasive contaminants in aquatic environments. They are characterized by persistence, toxicity, bioaccumulation, and long-range transport, significantly threatening human health. The development of sensitive methods for nitro-PAH analysis in environmental samples is in great need. This study developed a novel carbonaceous SPME coating derived from metal-organic framework (MOF), namely a spherical assembly consisting of carbon nanorods with hierarchical porosity (HP-MOF-C), for the extraction and determination of nitro-PAHs in waters. The HP-MOF-C coated fiber demonstrated superior nitro-PAH extraction efficiencies, with enrichment factors 2∼70 times higher than commercial fibers. This enhancement was due to the strong hydrophobic, π-π electron coupling/stacking, and π-π electron donor-acceptor interactions between the carbonaceous framework of HP-MOF-C and the nitro-PAHs. Moreover, the unique hierarchical porous structure of HP-MOF-C accelerated the diffusion of nitro-PAHs, further facilitating their enrichment. The fiber also exhibited good thermal stability, remarkable chemical stabilities against common acid, base, and polar/non-polar solvents, and long service life (> 150 SPME cycles). The nitro-PAH determination method based on HP-MOF-C coating yielded wide linear ranges, low detection limits (0.4∼5.0 ng L-1), satisfactory repeatability and reproducibility, and good recoveries in real water samples. The proposed method was considered to be green according to the Analytical GREEnness assessment. The present study not only offers an efficient SPME coating for the enrichment of nitro-PAHs, but also provides insights into the design of porous coating materials.

Application of zwitterionic ionic liquid-based capsule phase microextraction for the HPLC-UV determination of doxycycline in human urine samples

Herein, we describe the utilization of an ionic liquid (IL)/Carbowax 20 M-functionalized sol-gel sorbent for the capsule phase microextraction of doxycycline in authentic human urine samples. This green sample preparation method combines stirring and filtration in a single, standalone sample preparation device, streamlining the sample preparation process. Additionally, it provides rapid extraction kinetics and high extraction efficiency. The experimental conditions (i.e. sorbent type, sample pH and volume, extraction time, ionic strength, elution solvent, and volume) affecting the extraction efficiency of the analyte were studied and optimized. The method was linear in the range of 0.1 - 5.0 μg/mL with a coefficient of determination higher than 0.995. The achieved LOD was found to be 0.02 μg/mL while the lower limit of quantitation (LLOQ) was 0.1 μg/mL. The IL/Carbowax 20 M-functionalized microextraction capsules were reusable at least 30 times for urine samples. The relative recoveries (% RR) ranged between 93.4 - 115.9 % while the precision (expressed as % RSD) was better than 8.1 % in all cases. The robustness of the microextraction procedure and the instrumental HPLC method were separately investigated using Plackett-Burman experimental designs. The analytical protocol demonstrated cost-effectiveness, ease of handling, and speed, leading to increased sample throughput. The green character of the developed method was evaluated using the Green Analytical Procedure Index (GAPI) and Blue Applicability Grade Index (BAGI). Finally, the method's applicability was demonstrated by analyzing authentic human urine samples after oral administration of a doxycycline-containing pharmaceutical formulation.

Exploiting the Applicability of Polytetrahydrofuran-Modified Polyester for the Fabric Phase Sorptive Extraction of Doxycycline from Human Urine

In this report, a polytetrahydrofuran-coated polyester fabric phase sorptive extraction (FPSE) for the determination of doxycycline in human urine was described. The sol-gel polytetrahydrofuran sorbent proved to be superior against other sol-gel coated cellulose and polyester membranes tested. The effect of the extraction parameters including membrane surface area, sample pH and volume, salt concentration, extraction time, stirring rate, etc., on the extraction efficiency of the analyte was studied using the "one-factor-at-a-time" (OFAT) and Box-Behnken design approaches. The analytical method proposed was validated in compliance with FDA guidelines for bioanalytical procedures. The method was linear in the determination range of 100-5000 ng/mL with the determination coefficient of 0.9953. The limit of detection (LOD) and the lower limit of quantification for doxycycline was 17 and 100 ng/mL, respectively. The relative recoveries for intra-day and inter-day studies ranged from 98.5-112.2% and 89.6-96.8%, respectively. The relative standard deviation was lower than 14.7% in all cases, exhibiting good precision. The sol-gel polytetrahydrofuran-modified FPSE membranes were reusable for at least 30 times. The greenness of the developed method was evaluated using Sample Preparation Metric of Sustainability (SPMS) and Blue Applicability Grade Index (BAGI) metric tools. Finally, the analytical scheme was successfully employed for the quantitation of urinary doxycycline collected at various time points following the administration of doxycycline-containing tablets.

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

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

Anticancer Drug Extraction from Plasma Samples Using Three-Dimensional Polyoxometalate-Based Supramolecular Frameworks as Sorbents

Four self-assembled inorganic-organic hybrid materials, namely, H{Na(H2O)3[Gd(PDA)(H2O)2]3[BW12O40]}·4H2O (1), H{Na(H2O)3[Tb(PDA)(H2O)2]3[BW12O40]}·3H2O (2), H{Na(H2O)3[Er(PDA)(H2O)3]3[BW12O40]}·H2O (3) (PDA = 1,10-phenanthroline-2,9-dicarboxylate), and [Pr3(H2O)13(pydc-OH)2][BW12O40]·12H2O (4) (pydc-OH = 4-hydroxy-2,6-pyridinedicarboxylate), were hydrothermally synthesized and structurally characterized. Hybrids 1-3 are isostructural and contain a Keggin unit, which is linked to lanthanoids to produce distinct trinuclear lanthanoid building blocks. The fragments are connected by anion-π and hydrogen bonding interactions to create 3D networks. In hybrid 4, a trimeric Pr-organic species bearing a Keggin unit forms a 2D coordination polymer, and then hydrogen bonding interactions between 2D layers lead to the formation of a 3D structure. These polyoxometalate-based frameworks were used as sorbents for the dispersive microsolid-phase extraction (D-μSPE) of two anticancer drugs (doxorubicin and epirubicin) in human plasma samples. Analytes were quantified and separated using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The method's linearity was between 0.8-500 ng mL-1 and 1.0-500 ng mL-1 for the antineoplastic drugs doxorubicin and epirubicin, respectively. The limits of detection (S/N = 3) were in the range of 0.2-0.3 ng mL-1, while the precision was in the range of 3.5-4.3%. Finally, human plasma samples from patients treated with doxorubicin or epirubicin were analyzed by using the D-μSPE-HPLC-FLD method.

Fabricating a designer capsule phase microextraction platform based on sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent for the extraction of lipid-lowering drugs from human urine samples

A sol-gel Carbowax 20 M/3-[(3-Cholamidopropyl) dimethyl ammonio]-1-propanesulfonate composite sorbent-based capsule phase microextraction device has been fabricated and characterized for the determination of four statins (pravastatin, rosuvastatin, pitavastatin, and atorvastatin) in human urine. The presence of ionizable carboxyl functional groups in statins requires pH adjustment of the sample matrix to ensure that the target molecules are in their protonated form (pH should be 2 units below their pKa values) which not only is cumbersome but also risks unintended contamination of the sample. This challenge was addressed by introducing zwitterionic ionic liquid in addition to neutral, polar Carbowax 20 M polymer in the sol-gel-derived composite sorbent. As such, the composite zwitterionic multi-modal sorbent can simultaneously extract neutral, cationic, and anionic species. This particular attribute of the composite sorbent eliminates the necessity of the matrix pH adjustment and consequently simplifies the overall sample preparation workflow. Various experimental parameters such as the sample amount, extraction time, salt addition, stirring rate, and elution solvent type that may affect the extraction performance of the statins were investigated using a central composite design and the one-parameter-at-a-time approach. The analytes and the internal standard were separated on a C18 column with gradient elution using phosphate buffer (20 mM, pH 3) and acetonitrile as mobile phase. The analytes were detected at 237 nm. The method was validated, and linearity was observed in the range 0.10-2.0 μg mL-1 for all compounds. The method precision was better 9.9% and 10.4% for intra-day and inter-day, respectively, while the relative recoveries were acceptable, ranging between 83.4 and 116% in all cases. Method greenness was assessed using the ComplexGAPI index. Finally, the method's applicability was demonstrated in the determination of the statins in authentic human urine after oral administration of pitavastatin and rosuvastatin-containing tablets.

Capsule Phase Microextraction Combined with Chemometrics for the HPLC Determination of Amphotericin B in Human Serum

This article discusses the use of a sorbent-based microextraction technique employing a capsule device to isolate amphotericin B (AMB) from human serum before analysis by high performance liquid chromatography (HPLC). AMB is a macrocyclic compound used for the treatment of invasive fungal infections. Before determining AMB in human serum by HPLC, a sample preparation step is required. Capsule phase microextraction (CPME) integrates the stirring and filtration mechanisms in a single unit, simplifying the sample preparation procedure. Moreover, it results in fast extraction kinetics and high extraction efficiency, while it has proved to be a powerful tool for bioanalysis. Different sol–gel sorbent encapsulated microextraction capsules were investigated, and sol–gel Carbowax 20 M was finally chosen as the basis for the microextraction device. Accordingly, the sample preparation protocol was investigated using a face-centered central composite design to achieve good extraction performance. The optimum protocol was validated in terms of linearity, selectivity, limit of detection (LOD), limit of quantitation (LOQ), precision, and accuracy. The linear range of the developed approach was 0.10–10.0 μg mL−1. The LOD value was 0.03 μg mL−1, and the LOQ value was 0.10 μg mL−1. Method accuracy (expressed as relative recovery) was 87–113%, while the relative standard deviation of the repeatability (sr) and within-laboratory reproducibility (sR) were <12.4%. The sol–gel sorbent encapsulated microextraction capsules were reusable for at least 10 extraction cycles. All things considered, the proposed method exhibited good overall performance, and it could be used in bioanalysis for quality control, therapeutic drug monitoring and research purposes.