Analytical and Bioanalytical Chemistry Research
Volume:10 Issue: 3, Summer 2023

Blast furnace slag (BFS) was exploited as an adsorbent for the removal of Cr (III), Pb (II), and Cr-Pb. In discontinuous mode, the influence of the contact time, stirring speed, pH, mass of the adsorbent, initial concentration, and temperature were examined. The physico-chemical tests indicated that the BFS is formed from a mixture composed mainly of silicates, aluminates, lime, and magnesium oxide. Its specific surface is 325.6m2/g and the pHzpc value corresponds to 3.8. Experimental results have indicated that the equilibrium is obtained after 60, 50, and 80 minutes for Cr(III), Pb(II), and the Cr-Pb mixture, respectively. Under our experimental conditions (pH 4.8, Vag: 150rpm, T: 20°C, Øs: 200μm, and Ms: 1g), the adsorption capacities of Cr(III), Pb(II), Cr-Pb, Cr(III) in the mix, and Pb(II) in the mix were 43.16, 50.12, 39.91, 17.05, and 22.66mg/g, respectively. Moreover, BFS has more affinity for lead in the binary mixture. The adsorption isotherms revealed that the Langmuir model was the best fit for the metal ion adsorption processes examined (R2= 0.99). The kinetics indicated that the adsorption of the metal ions studied follows the pseudo-second order model and that their transfers from the solution to the adsorbent are controlled by external and intraparticle diffusion. The thermodynamic study has shown that all the processes applied are spontaneous, exothermic and less entropic. The desorption of the binary mixture revealed that saturated BFS can be efficiently exploited over four cycles, and it is more efficient in the presence of HCL at 0.1N.

This study reported a electrochemical sensor based on molecularly imprinted polymer (MIP) for simultaneous and selective detection of Ascorbic acid (AA) and Tyrosine (Tyr). The MIP film was electropolymerized on the glassy carbon electrode (GCE) using of o-aminophenol (o-AP) and m-dihydroxy benzene (m-DB) as monomers and the dual analyte of AA and Tyr, and its electrochemical performance was evaluated. Influencing parameters such as the pH value, electropolymerization cycle numbers, and template/monomer ratio were optimized. The differential pulse voltammetry (DPV) technique was used for the simultaneous and individual determination of AA and Tyr in their binary mixture. The introduced sensor showed the linear concentration ranges of 0.1-300 µM for AA and 0.01-180 µM for Tyr and good limits of detection were 0.03 µM and 0.003 µM, respectively. The proposed sensor was successfully employed to detect AA and Tyr in real samples. The recoveries were from 97 to 105% and the RSD was less than 3.5% which exhibited the usability of this sensor in the real sample.

The sustained release potential of bioactive materials and drugs is a major requirement in the development of carriers for cancer treatment. In this study, Carboplatin (Crb) as a standard anticancer drug was loaded to immunoglobulin G nanoparticles (IgGNPs) in the absence (Crb@IgGNPs) and the presence of folic acid (FA), (Crb@FA.IgGNPs) as a targetable agent. Their physicochemical properties were characterized by various techniques. Dynamic light scattering (DLS) technique indicated that the average hydrodynamic diameter and zeta potential values of Crb@IgGNPs and Crb@FA.IgGNPs were 831.23±4.95 nm; (PDI: 0.980.31), 397.47±22.96 nm; (PDI: 0.780.08) and -2.97±1.17 mV, -7.06±0.72 mV, respectively. The spherical shapes of the nanocarriers showed more particle size distribution in Crb@FA.IgGNPs are confirmed by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Fourier-transform infrared (FTIR) spectra of nanocarriers confirmed Crb loading onto IgGNPs and FA.IgGNPs. Afterwards, In vitro release study of Crb and Crb@FA.IgGNPs was performed that demonstrated Crb was slowly released from FA.IgGNPs (about 61 h longer than only Crb) and the release mechanism was followed by korsmeyer-peppas model with Fickian diffusion. Overall, it was observed that the novel designed drug carrier improved the drug release with the appropriate properties for clinical approaches.

A novel electrochemical immunoelectrode was fabricated for Serum Amyloid A protein (SAA) sensing using gold nanoparticles modified electrode. The present study reports the optimisation of electrochemical deposition parameters for gold nanoparticles (AuNPs) on ITO (Indium-tin-oxide) surface. AuNPs were electrochemically deposited on APTES (3-Aminopropyl) triethoxysilane) modified ITO surface to prepare working electrode (AuNP/APTES/ITO). This electrode is further used to fabricate immunoelectrode SAA-Ab/AuNP/APTES/ITO by immobilising SAA specific antibodies (SAA ½ Ab) on its surface. Characterization of prepared immunoelectrode is done by electrochemical characterization techniques (differential pulse voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy), scanning electron microscopy and XRD. Sensing by electrochemical techniques revealed that fabricated immunoelectrode can detect SAA when 10 μl of it (from initial concentration of 10 fg/ml to 105 fg/ml) is poured on immunoelectrode and kept for 10 minutes every time. Linearity equation is obtained with lowest used concentration of SAA biomarker 10 fg/ml and the limit of detection (LOD) has been calculated using the equation 3σ/sensitivity which comes out to be 6.867 fg/ml.

The aim of this study was to investigate the applicability of UV-Vis and FT-IR fingerprints combined with multivariate statistical tools to classify and authenticate Iranian standard herbs and spices, their mislabeled and adulterated samples in single and fusion model. The proposed strategy is as an alternative, rapid, easy, and economical approach for of the herbs and spices authentication. Sixty three samples of different herbs and spices were collected across several cities of Iran. The potency of Savitzky-Golay(SG) smoothing in combination with autoscaling for improving accuracy of clustering well studied and principal component analysis (PCA), PCA – linear discriminant analysis (PCA-LDA) and partial least squares - discriminant analysis (PLS-DA) were applied for classification. Additionally, data mining of spectral sets was performed using Kohonen self-organization maps (SOMs) of smoothed and unsmoothed individual data sets and classification results were compared. Also, the discriminant models using fusion matrix was built by concatenation of SG smoothed-atoscaled SOMs clusters of FTIR and UV-Vis (SG- autoscaled- SOMs) spectra. The results of different models showed that accuracy of single SG- autoscaled- SOMs-FTIR data was better than SG- autoscaled- UV-Vis data and the accuracy of SG- autoscaled- SOMs -fusion technique was better the other models. This method predicted class of samples more accurately (more than 95 %). The authentication and quality of fraud samples were identified more correctly with respect to raw data.

Vinasse is a well-known associate of sugar cane/beet ethanol production wastewater. In the present work, the electrocoagulation technique at a constant current intensity combined with circulation flow introduces as a new and economic method for the treatment of vinasse effluent using iron and/or aluminum without changing the initial conditions of sample solution. Spectrophotometric determination was used to quantify the COD and turbidity in effluents as the most regarded vinasse footprints. The proposed CCD method was used as an experimental design, having as independent variables, applied current, pH, electrode material, and the reaction time, evaluated for highest COD, turbidity, and color removal. The optimum conditions for removal of COD, color and turbidity determined by response surface modeling (RSM) showed that the proposed circulating electrocoagulation (CEC) method using aluminum-graphite electrodes at 1 A current, pH 7 and reaction time of 45 min is able to be used with high efficiency for the treatment of vinasse wastewater in ethanol production industry. The proposed method is very simple, cheap and fast and can be used as a pilot system in alcohol factories to recover the water which can, in turn, be utilized for agricultural purposes and other industries.

Silver nanoparticles modified with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (AgNPs-AHMT) have been developed as colorimetric sensors for cortisol detection as a stroke biomarker. This method’s principle was based on AgNPs-AHMT aggregation with cortisol due to the hydrogen bonding interaction between the surfaces of AHMT and cortisol. This process caused the color change that can be seen with the naked eye. Then, it is confirmed by ultraviolet-visible (UV-Vis) spectroscopy, particle size analyzer (PSA), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The color of colloidal AgNPs-AHMT changed from yellow to brownish orange, giving a red shift in the localized surface plasmon resonance (LSPR) peak. The quantitative monitor for cortisol determination had good linearity in the range of cortisol concentrations of 1.0–50.0 nM, with a limit of detection (LOD) and a limit of quantification (LOQ) of 0.719 nM and 2.37 nM, respectively. The relative standard deviations (RSD %) for intra-day and inter-day were <3.2 % and <2.26 %, respectively. Moreover, this method was applied for cortisol detection in a saliva sample. So, the simple, rapid, and real-time strategy exhibited a promising potential for cortisol detection in a saliva sample.

Carbon paste electrodes have been developed to improve the performance and selectivity of electrodes for the potentiometric analysis of amitriptyline (AMT). Carbon paste electrodes modified with imprinted zeolites (IZ) were developed as potentiometric sensors for AMT analysis. In this study, zeolite X was synthesized using Na2O, Al2O3, SiO2, and H2O at a mole ratio of 4.5: 1: 3: 315. The IZ was synthesized by adding AMT to the mixture at an AMT/Si molar ratio of 0.0306 as a template. Subsequently, AMT was extracted from the zeolite framework to form active and selective AMT recognition sites. The optimum performance was achieved by the electrode composed of activated carbon, paraffin, and IZ at a composition of 12:7:1, which was expressed by a Nernst factor of 28.38 mV/decade, measurement range of 10-5–10-2 M with a correlation coefficient of 0.9994, and a low detection limit of 1.15 × 10-5 M. The detection limit can accommodate the lower dose of AMT in pharmaceuticals. The modified electrode had precision of 97.5–99.9% and accuracy of 91.2–107%, with a response time of 24–211 s. Moreover, it was stable for four weeks after more than 100 uses. Application of the modified electrode in the determination of AMT in three pharmaceutical samples resulted in a 96–102% recovery. The presence of glucose, lactose, mannitol, and ZnSO4 had no effect on the potentiometric analysis of AMT using the modified electrode. The excellent analytical performance of the modified carbon paste electrode suggests its potential applications in the analysis of AMT, an affordable medicine.

The combined use of antihypertensive drugs in the treatment of hypertension and prevention of heart attack has become a very important approach in health care. Valsartan (VAL) and Amlodipine (AML) are two kinds of antihypertensive agents that are used as exforge in the treatment of cardiovascular disease. Clarifying the mechanism and kinetics associated with the release of these drugs is of a great importance to establish an efficient drug delivery system. The aim of this study is to use Multivariate Curve Resolution–Alternating Least Squares (MCR-ALS) in the analysis of the in vitro kinetic-spectrophotometric data of simultaneous release of AML and VAL from the poly-(acrylic acid-co-2-hydroxyethyl methacrylate) cross-linked by butanediol dimethacrylate P(AA-co-HEMA)-BDMA at pH=5.5 and 37 ºC to obtain the kinetic profiles. Successful loading of drugs on P(AA-co-HEMA)-BDMA was confirmed by investigating the FT-IR spectrums of polymers with and without the loaded drugs. Various mathematical models were exploited to fit the release profile of the drugs. Based on the obtained values for the correlation coefficient (R2), the release kinetics of both drugs match the Korsmeyer-Peppas model.

In this study, a new electrochemical sensor using MIPs coated on the surface of Cu-MOF was developed for the selective determination of chlorpyrifos (CPF). Cu-MOF (HKUST-1) was synthesized based on a solvothermal method. Molecularly imprinted polymers (MIPs) were prepared using chlorpyrifos as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethyacrylate as the cross-linker. The optimum pH value of the rebinding solution was verified with computational calculations obtained by Gaussian software. The HKUST-1 @MIP was characterized by several technique include, Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). HKUST-1 @MIP/GEC electrode showed an excellent linear range of 0.01 to 1.00 µM, with RSD% and LOD of 5.37% and 3 nM, respectively. The modified electrode presents a simple, selective, sensitive, stable and environmentally friendly strategy for the determination of CPF. The proposed method was successfully used to measure CPF in apple and tomato samples.