biological samples

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used painkillers but can have side effects, making it essential to measure their concentration in biological fluids. In this study, a CoFe2O4@HKUST-1 coating was applied to a capillary glass tube via a hydrothermal method. The coated tube was then used as a solid-phase microextraction (SPME) fiber to detect four NSAIDs (Ibuprofen, Nalidixic acid, Diclofenac, and Naproxen) using HPLC with a UV detector in plasma, urine, and serum samples. Optimization of variables (the initial pH of the sample solution, concentration of salt, time of extraction, and rate of stirring) was done with the Box-Behnken design and one-variable-at-a-time method (pH, type and volume of desorption solvent). The linear range (LR) was 0.06-450 μg L−1 with R2>0.9970, and the limit of detection (LOD) and quantification (LOQ) were 0.01-0.04 μg L−1 and 0.04-0.14 μg L−1, respectively. The relative standard deviation percentage (RSD %) was 1.33-5.43%, and recoveries ranged from 94.45% to 99.00%. This fiber is cost-effective, durable (>112 extractions), and demonstrates superior LOD and LR compared to other methods, making it ideal for monitoring NSAID levels. The magnetic HKUST-1 coating enhances extraction efficiency two to four times compared to nonmagnetic HKUST-1, making CoFe2O4@HKUST-1 a highly efficient sorbent.

This study was conducted to develop liquid-phase microextraction approach using ferrofluid based on cobalt ferrite nanoparticles coupled with UV–Vis spectrophotometry (LPME-FF-UV-Vis) as a simple, green, inexpensive, available and high efficiency method for separation/pre-concentration and determination trace‑level of uric acid (UA) in biological samples. First, CoFe2O4 nanoparticles were synthesized by hydrothermal method and characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer (VSM), energy dispersive X-ray spectroscopy (EDXS), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). Based on preliminary studies and experiments, four parameters including pH, ferrofluid volume, temperature and ultrasonic time were selected as influential variables and optimized by central composite design (CCD). Under optimal conditions the calibration curve was linear in the concentration range of 0.42–238 μM and the limit of detection was obtained 0.12 μM. Also, the relative standard deviation for the repeatability and reproducibility were 2.1% and 3.0 %, respectively. Finally, the efficiency of LPME-FF-UV-Vis method was investigated for the detection and trace quantification of UA in human urine samples and validated via the analysis of the selected real samples by the high performance liquid chromatography-ultraviolet detection (HPLC-UV) as a reference method. The relative recovery percentages above 94 % for determination of UA confirmed the accuracy and efficiency of the proposed method.

In this study, a dispersive magnetic solid phase extraction (DMSPE) was described by combining graphene oxide (GO) with Fe3O4 and CuO (Fe3O4@CuO&GO) for extraction and preconcentration of aspirin (ASP) in biological samples. The morphology and structure of the prepared nanocomposite was characterized and analyzed by XRD, SEM and FTIR techniques. Ion mobility spectrometry (IMS) method equipped to a corona discharge ionization source was exploited to determine ASA. The extraction parameters (desorption solvent, pH, adsorbent amount, extraction time and temperature) and also the operational parameters of IMS were investigated and optimized. Under the optimum conditions, the DMSPE–IMS method provided a linear range 6.0–40.0 ng for ASA with coefficient of determination R2 = 0.99. The LOD and LOQ values were 0.9 and 3.0 ng for ASA, respectively. The repeatability of developed method was evaluated as relative standard deviation (RSD% = 2.7). The proposed method was also used to determine ASA in human plasma and serum as biological samples, which recovery results were within 89.0–100.0%.

The current research examines the designation of an electrochemical sensor for the simultaneous measurement of morphine and methadone using graphene oxide /multi-walled carbon nanotube/zinc oxide nanorods/polypyrrolenanocomposite, coated on the surface of the graphite electrode reinforced by a hollow fiber.Its performance was investigated by voltammetry methods while the nanocomposite structure was confirmed by FTIR, EDX, XRD, and SEM techniques.To optimize the effectual factors, the Taguchi test designing method with L27(3x7) orthogonal array was applied. Thevoltammetricanalysisshowed that two irreversible oxidation peaks appeared at the potentials of 0.81 V and 0.41 V for methadone and morphine, respectively. Furthermore, the electrochemical investigations showed that the oxidation process of morphine and methadone wasunder the control of the diffusion phenomenon and two electrons and two protons had been exchanged on the surface of the electrode for bothanalytes. Chronoamperometry was used to measure the diffusion coefficients of drugs which were found for morphine and methadone to be 5.31×10-6 cm2s-1 and 1.19×10-6 cm2 s-1. Under optimal conditions, for morphine, two linear concentration ranges of 0.04-10 μM and 10.0-100 μM and a detection limit of 0.01 μM were noted whereas for methadone, two linear ranges were observed in 0.06-8.0 μM and 8.0-100 μM and the detection limit was 0.02 μM. The designed sensor can be well used for the simultaneous measurement of the drugs with relative recovery percentages in the range of 98.80-100.22%for morphine and in the range of 98.14-100.58% for methadone.

Clopidogrel with trade name plavix, is used effectively to reduce the incidence of ischaemic strokes, heart attacks and claudication. In this study, an ion mobility spectrometry (IMS) method was proposed for the clopidogrel determination in analytical and bio-analytical fields. Under experimental conditions, the analytical validation parameters of the proposed method were calculated and reported. The calibration graph was linear in range 30.0–2000.0 µg mL-1 for clopidogrel with two orders of magnitude and a goodness of fit, R > 0.99. The coefficient of variation (precision, n=10) was found to be within 7.5–8.6%, and also the concentration levels of 3.0 and 10.0 µg mL-1 from analyte were obtained for the limits of detection and quantification, respectively. The developed IMS method was successfully applied to determine clopidogrel with accurate recovery range (90.0–103.7%) in different matrices. The validation studies showed that the applied IMS was a simple, rapid, sensitive and reliable method for the clopidogrel analysis in the pharmaceutical and biological samples.