Porous eco–friendly fibers for on–line micro solid–phase extraction of nonsteroidal anti–inflammatory drugs from urine and plasma samples

Modification of cellulose substrate by in situ synthesis of metal-organic framework-5 for thin film microextraction of some non-steroidal anti-inflammatory drugs and their measurement by high-performance liquid chromatography-ultraviolet detector

This work, reports the successful preparation a thin film by a simple and inexpensive process for quantification of a model analytes in the urine sample using HPLC-UV. To this end, cellulose paper was employed as a substrate for the in-situ synthesis of MOF-5, to increase the resistance of the prepared film. The prepared film can be reused 26 times with no reduction in its performance. The thin film prepared by MOF-5 modified cellulose substrate was utilized in thin film microextraction (TFME) method for the extraction and preconcentration of naproxen, aspirin, tolmetin, and celecoxib. Under optimal conditions, the linear dynamic range of the target analytes was 2-500 µg L-1 with correlation coefficients (R2) ranging from 0.9961 to 0.9990. Also, the limits of detection (LODs), the limits of quantification (LOQs) and relative standard deviation (RSD%) of the proposed method for selected analytes ranged between 0.57 and 0.77 µg L-1, 1.7 to 2.3 and 3.5 % to 6.2 %, respectively. Moreover, relative recoveries varied from of 94 % to 108 %, indicating the absence of matrices effect in the proposed method. Eventually, the TFME was successfully used for the extraction of selected analytes from urine samples.

Mesoporous organosilicas with highly-content tyrosine framework as extractive phases for non-steroidal anti-inflammatory drugs in aquatic media

BACKGROUND

Attentions regarding ordered mesoporous silica materials (OMSs), with large specific surface areas and narrow pore size distribution, which are prepared via self-assembly techniques, have been raised in sorption, separation, and sample preparation. However, in order to extend and improve their applications, a functionalization step is required. Organic units can be anchored on the inner or outer surface as well as in the silica wall framework by co-condensation-, grafting-, and periodic mesoporous organosilica (PMO) preparation approaches. Apparently, by synthesizing PMO with extensive and flexible organic bridging groups within the mesoporous wall, an efficient extractive phase can be achieved.

RESULTS

We employed tyrosine amino acid to synthesize a PMO-based extractive phase. The FT-IR, 1H NMR, HR-ESI-MS, Low angle-XRD, TEM, FESEM, BET, and EDX-MAP analyses confirmed the successful synthesis of PMO within the salt-assisted templating method. A comprehensive study on sorption behavior of PMO was performed and its efficiency was evaluated against the grafting and co-condensation methods. Then, it was implemented to the pipette tip-micro solid phase extraction (PT-μ-SPE) of widely used non-steroidal anti-inflammatory drugs (NSAIDs) in water/wastewaters. Limits of detection and quantification were obtained in the range of 0.1-1.5 and 0.3-5 μg L-1, respectively. The calibration plots are linear in the 1-1000, 3-1000, 10-750, and 3-750 μg L-1, respectively. The intra-and inter-day precision at 50 and 200 μg L-1 levels are 2.9-7.1 % and 3.5-8%, while recoveries are between 84 and 111 %.

SIGNIFICANCE

High-capacity tyrosine functionalized PMO with 2D hexagonal symmetry silica mesoporous structures found to be highly efficient extractive media. Despite the bulkiness and flexibility of the bridging group within the mesoporous wall, the synthesis condition was optimized in order to load more organic content in the PMO structure. The PMO performance was superior over organically modified ordered mesoporous silica materials prepared by the grafting and co-condensation methods.

[Determination of three urinary catecholamines and serotonin by on-line packed-fiber solid-phase extraction]

生物单胺包括儿茶酚胺类以及5-羟色胺等,在中枢神经系统中扮演着非常关键的角色,也是临床上诊断神经内分泌肿瘤疾病的重要生物标志物。由于这类单胺类物质的强化学极性导致传统吸附材料对其吸附效果不佳,从复杂生物样本中同时检测更多的生物单胺存在挑战性。该文建立了一种基于聚冠醚纳米纤维在线固相萃取检测尿液中3种儿茶酚胺(多巴胺、肾上腺素、去甲肾上腺素)和5-羟色胺的方法。采用静电纺丝法制备聚二苯并-18-冠-6醚-聚苯乙烯复合纳米纤维(PCE-PS),制成装填纤维的固相萃取(PFSPE)柱,再将PFSPE柱与HPLC进行在线联用。该在线PFSPE-HPLC方法采用双三元泵进行样品富集净化和分析,左泵连接PFSPE柱,进行样品富集净化;右泵连接分析柱进行样品分离检测。控制切换阀的切换,实现样品富集后洗脱至分析柱中分离检测。结果表明,在线PFSPE-HPLC检测尿液儿茶酚胺(多巴胺、肾上腺素、去甲肾上腺素)和5-羟色胺在1~200 ng/mL范围内有良好的线性关系,线性相关系数达0.996以上。3种儿茶酚胺和5-羟色胺的检出限(S/N=3)分别为1和2.5 ng/mL,定量限(S/N=10)分别为2.5和5 ng/mL。空白尿液和实际尿液加标回收率在83.5%~117.7%之间,日内精密度<10%。PCE-PS复合纳米纤维在多次使用后无明显变化,具有良好的稳定性,可重复使用达95次以上。在线PFSPE-HPLC方法能够集样品在线前处理与分析检测于一体,省时省力,实现分析过程的高度自动化。该方法成功应用于尿液中3种儿茶酚胺和5-羟色胺的检测,可以为临床上相关疾病检测诊断和研究提供有力的技术支持。

Imine-linked covalent organic frameworks coated stir bar sorptive extraction of non-steroidal anti-inflammatory drugs from environmental water followed by high performance liquid chromatography-ultraviolet detection

In this study, spherical imine-linked covalent organic frameworks (COFs) were fabricated from 2,5-dimethoxybenzene-1,4-dialdehyde (DMTP) and 1,3,5-tris (4-aminophenyl) benzene (TAPB) and named as TAPB-DMTP-COFs. The resulting powders were coated onto bare glass bars via physical-adhesion to obtain TAPB-DMTP-COFs coated stir bars. The self-made stir bars exhibited higher extraction efficiency (74-85%) and faster dynamics (50 min) towards non-steroidal anti-inflammatory drugs (NSAIDs) over ethylene glycol-Silicone (42-68%, 180 min) and polydimethylsiloxane (3-61%, 180 min) coated stir bars. Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), zeta potential and water contact angle were employed to provide a comprehensive understanding of the adsorption mechanism between the coating and analytes. The results displayed that methoxy group worked as an adsorption site helping the adsorption of interest NSAIDs onto the TAPB-DMTP-COFs coating and hydrogen bonds formed between the O atoms and the analytes. Additionally, the adsorption mechanisms possibly also involved π-π interaction and hydrophobic interaction. Moreover, TAPB-DMTP-COFs coated stir bars exhibited good stability and could be reused more than 60 times. Subsequently, a method by combining TAPB-DMTP-COFs coated stir bar sorptive extraction (SBSE) with liquid chromatography (HPLC)-ultraviolet detector (UV) was established for the determination of four NSAIDs in environmental waters. Under the optimized conditions, the established method showed a wide linear range of 0.2/1-500 μg/L for interest NSAIDs, the limits of detection varied from 0.039 to 0.312 μg/L. Yangtze River water, East Lake water and Spring water were subjected to the proposed method, the recoveries in spiked samples were 84.7-104%, 81.2-101% and 82.6-97.6%, respectively.

Preparation of amine-modified lignin and its applicability toward online micro-solid phase extraction of valsartan and losartan in urine samples

In the present work, with the focus on an environmentally-friendly approach, some gels were prepared by synthesizing amine-modified lignin, extracted from sugarcane bagasse, and further esterification and subsequent freeze-drying. These lignin-based gels were implemented as extractive phases in an online micro-solid phase extraction (μSPE) setup in conjunction with high performance liquid chromatography (HPLC) with UV detector. The developed method was used for analytical determination of valsartan and losartan in urine samples. To study the effect of the functionalization process, the efficiency of the unmodified lignin and the functionalized lignin were compared both in the absence and the presence of graphene oxide (GO), presumably as a suitable doping agent. Surprisingly, higher extraction efficiency for the functionalized lignin, compared to both unmodified lignin and GO was observed. The amination process for the prepared gel was analyzed and proved by CHNS elemental analysis and Fourier transform infrared (FT-IR) spectroscopy. The morphology of sorbet was investigated via scanning electron microscope (SEM) imaging and a nanoscale cauliflower feature was observed. The method was optimized and subsequently applied to the analysis of the urine samples. Limits of detection (LOD) of 8 and 6 µg L ^- 1, limits of quantification (LOQ) of 27 and 20 µg L ^- 1 and linear dynamic range (LDR) of 27-2000 and 20-2000 µg L ^- 1 with intraday relative standard deviations (RSD%) of 4 and 3% were obtained for valsartan and losartan, respectively. The whole online μSPE-HPLC setup was conveniently used for the analysis of a patient urine sample and a quantity of 352 μg L ^- 1 of losartan was found. Acceptable relative recoveries (109-108 and 95-94% for valsartan and losartan) revealed the analytical potential of the method for the determination of drugs in complex urine samples.

Comparison of three electromembrane-based extraction systems for NSAIDs analysis in human urine samples

A comparative study on the extraction efficiency of five non-steroidal anti-inflammatories was carried out using three different electromembrane extraction (EME) devices with different geometries. The employed setups were (a) a hollow fiber configuration (HF-EME), (b) a microfluidic device that allows working in semi-dynamic mode (μF-EME), and (c) a static miniaturized flat membrane device (FM-EME). Each system was applied to the extraction of salicylic acid (SAC), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC), and ibuprofen (IBU) and subsequent determination by high-performance liquid chromatography with UV and fluorescence detection (HPLC/UV-DAD-FLD). Voltage, pH composition, and extraction time were optimized for all devices. Additionally, volume ratio was investigated for HF-EME and FM-EME and flow rate for the microfluidic device. HF-EME provides the best result in terms of sensitivity with a limit of detection (LOD) between 0.1 and 1.5 ng mL^-1 for SAC and KTP, respectively, while LODs for μF-EME were between 100 ng mL^-1 and 400 ng mL^-1 for SAC and DIC, respectively; however, a lower amount of sample was required. Finally, the obtained results, in terms of enrichment factors and extraction recoveries, were discussed to establish the advantages and disadvantages of each device. The proposed EME methods were successfully applied to the determination of the target analytes in fortified human urine samples. Graphical abstract.

Simultaneous Analysis of Paracetamol and Diclofenac Using MWCNTs-COOH Modified Screen-Printed Carbon Electrode and Pulsed Potential Accumulation

A differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure with the use of pulsed potential accumulation and carboxyl functionalized multiwalled carbon nanotubes modified screen-printed carbon electrode (SPCE/MWCNTs-COOH) was delineated for simultaneous analysis of paracetamol (PA) and diclofenac (DF). The use of carboxyl functionalized MWCNTs and pulsed potential accumulation improves the analytical signals of PA and DF, and minimizes interferences from surfactants. After optimization of analytical conditions for this sensor, the peak currents of the two compounds were found to increase linearly with the increase in their concentration (5.0 × 10^-9-5.0 × 10^-6 mol L^-1 with a detection limit of 1.4 × 10^-9 mol L^-1 for PA, and 1.0 × 10^-10-2.0 × 10^-8 mol L^-1 with a detection limit of 3.0 × 10^-11 mol L^-1 for DF). For the first time, the electrochemical sensor allows simultaneous determination of PA and DF at concentrations of 24.3 ± 0.5 nmol L^-1 and 3.7 ± 0.7 nmol L^-1, respectively, in wastewater samples purified in a sewage treatment plant.

Quantification and validation of nine nonsteroidal anti-inflammatory drugs in equine urine using gas chromatography-mass spectrometry for doping control

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in therapeutic doses in human and veterinary medicine for the treatment of inflammation, pain, and fever. A method for the simultaneous determination of nine NSAIDs, known as therapeutic prohibited substances, in equine urine was developed and fully validated according to the European Commission Decision 2002/657/EC and Association of Official Racing Chemists criteria. The validation was performed for naproxen, flunixin, ketoprofen, diclofenac, eltenac, meclofenamic acid, phenylbutazone, vedaprofen, and carprofen in equine urine in accordance with the International Screening Limits (ISL) regulated by International Federation of Horseracing Authorities. After basic hydrolysis, samples were extracted with a C18 cartridge using automated solid-phase extraction. Several derivatization reagents were investigated, and trimethylphenylammonium hydroxide/methanol (20/80, v/v) was selected. Analyses were carried out using gas chromatography-mass spectrometry with selected ion monitoring mode, but the method can be applied to a large number of analytes. The within-laboratory reproducibility was not more than 12.8% (≤15%), and mean relative recoveries ranged from 91.1% to 104.1% for inter-day and intra-day precision. The decision limits (CCα) and detection capabilities (CCβ) were evaluated at concentrations near the ISL for each therapeutic substance. The validation results demonstrated that the method is highly reproducible, easily applicable, and suitable for the analysis of some NSAIDs in equine urine that have not been previously published. Finally, the method was also applied to known positive samples.

A Comprehensive Review on Developed Pharmaceutical Analysis Methods by Iranian Analysts in 2018

This article summarizes the publishing activities including bioanalytical and pharmaceutical analyses researches carried out in Iran in 2018 in order to connect academic researchers to those in industry, medical care units and hospitals. A wide spectrum of analytical methods has been used to determine and/or evaluate drug levels in the biological samples, based on physical, chemical and biochemical principles. We have compiled a concise survey of the literature covering 125 reports and tabulated the relevant analytical parameters. Chromatographic and electrochemical methods were found to be the technique of choice for many workers and almost 83% studies were performed by using these methods. This is the first annual review of the literature searching in SCOPUS database for published bioanalytical and pharmaceutical analysis researches in Iran.

Magnetic Solid-Phase Extraction Based on Poly 4-Vinyl Pyridine for HPLC-FLD Analysis of Naproxen in Urine Samples

A magnetic solid phase extraction technique followed by liquid chromatography with a fluorescence detector for naproxen analysis in human urine samples was developed. The method includes the extraction of naproxen with a magnetic solid synthetized with magnetite and poly 4-vinylpriridine, followed by the magnetic separation of the solid phase and desorption of the analyte with methanol. Under optimal conditions, the linear range of the calibration curve was 0.05–0.60 μg L⁻¹, with a limit of detection of 0.02 μg L⁻¹. In all cases values of repeatability were lower than 5.0% with recoveries of 99.4 ± 1.3%. Precision and accuracy values are adequate for naproxen (Npx) analysis in urine samples.

First Electrochemical Sensor (Screen-Printed Carbon Electrode Modified with Carboxyl Functionalized Multiwalled Carbon Nanotubes) for Ultratrace Determination of Diclofenac

A simple, sensitive and time-saving differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure using a screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes (SPCE/MWCNTs-COOH) for the determination of diclofenac (DF) is presented. The sensor was characterized using optical profilometry, SEM, and cyclic voltammetry (CV). The use of carboxyl functionalized MWCNTs as a SPCE modifier improved the electron transfer process and the active surface area of sensor. Under optimum conditions, very sensitive results were obtained with a linear range of 0.1–10.0 nmol L⁻¹ and a limit of detection value of 0.028 nmol L⁻¹. The SPCE/MWCNTs-COOH also exhibited satisfactory repeatability, reproducibility, and selectivity towards potential interferences. Moreover, for the first time, the electrochemical sensor allows determining the real concentrations of DF in environmental water samples without sample pretreatment steps.