Diclofenac In Water Samples Research Articles

A Bayesian Regularized Artificial Neural Network for Simultaneous Determination of Loratadine, Naproxen and Diclofenac in Wastewaters

Background:: Simultaneous determination of medication components in pharmaceutical samples using ordinary methods have some difficulties and therefore these determinations usually were made by expensive methods and instruments. Chemometric methods are an effective way to analyze several components simultaneously. Objective:: In this paper, a novel approach based on Bayesian regularized artificial neural network is developed for the determination of Loratadine, Naproxen, and Diclofenac in water using UV-Vis spectroscopy. Methods: A dataset is collected by performing several chemical experiments and recording the UV-Vis spectra and actual constituent values. The effect of a different number of neurons in the hidden layer was analyzed based on final mean square error, and the optimum number was selected. Principle Component Analysis (PCA) was also applied to the data. Other back-propagation methods, such as Levenberg-Marquardt, scaled conjugate gradient, and resilient backpropagation, were tested. Results:: In order to see the proposed network performance, it was performed on two crossvalidation methods, namely partitioning data into train and test parts, and leave-one-out technique. Mean square errors between expected results and predicted ones implied that the proposed method has a strong ability in predicting the expected values. Conclusion:: he results showed that the Bayesian regularization algorithm has the best performance among other methods for simultaneous determination of Loratadine, Naproxen, and Diclofenac in water samples.

Ultrasensitive detection of diclofenac in water samples by a novel surface-enhanced Raman scattering (SERS)-based immunochromatographic assay using AgMBA@SiO2-Ab as immunoprobe

In the last years, surface-enhanced Raman scattering based immunochromatographic assay (SERS-ICA) has been getting great attention and been applied for the detection of different target analytes. In this study, a novel SERS-ICA using AgMBA@SiO2-Ab as an immunoprobe has been developed for rapid, quantitative and ultrasensitive detection of a pharmaceutical diclofenac (DCF) residue in water samples. Ag, Ag@SiO2 and AgMBA@SiO2 nanoparticles (NPs) were synthesized and characterized. The immunoprobe was prepared by sandwiching the Raman reporter mercaptobenzoic acid (MBA) between the core-shell layers and immobilizing the monoclonal antibody (mAb) against DCF on the surface of the Ag@SiO2 NPs. Under optimal conditions, the sensitivity and limit of detection (LOD) of the SERS-ICA for DCF were found to be 9 pg mL−1 and 0.07 pg mL-1, respectively. The detection of the SERS-ICA for DCF was completed within 15 min. AgMBA@SiO2-Ab was stable within four months without significant loss of SERS intensity. The key to success of the SERS-ICA was the employment of the Ag@SiO2 NPs as the SERS substrate, which possessed gorgeous SERS enhancement capability, predominant biocompatibility and excellent stability. This SERS-ICA is potential as an ultrasensitive analytical method in point-of-care testing, clinical diagnosis, food inspecting and environmental monitoring.

Selective separation and determination of diclofenac via magnetic molecularly imprinted polymer and spectrophotometry

A simple, rapid and selective method for the separation/preconcentration and determination of diclofenac (DFC) based on the combination of extraction with the magnetic molecularly imprinted polymer (MMIP) and analysis via fiber optic-linear array spectrophotometer was developed. MMIP were prepared by precipitation polymerization, using SiO2-coated Fe3O4 nanoparticles as the magnetic components, DFC as the template molecule, 4-vinylpyridine (4-VP) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linker. The synthesized MMIP characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The main parameters affecting the extraction recoveries including the type and volume of desorption solvent, desorption time, sample pH, and extraction time were optimized. The highest extraction recovery (>98 %) was obtained by a mixture of the methanol and acetic acid (9:1, v/v) as the eluting solution. The Scatchard plot analysis indicates the formation of two classes of binding sites with the maximum capacity of 44.11 and 116.35 mg g−1. Under the optimum conditions, the calibration graph was linear (r 2 = 0.9994) in the range of 1–50 μg L−1 with a detection limit of 0.23 μg L−1 for the preconcentration of 100 mL of the sample and 0.5 mL of the eluent. This method was successfully applied to the determination of DFC in water samples, human blood serum, urine sample and pharmaceutical ampoules.

Removal of diclofenac by conventional drinking water treatment processes and granular activated carbon filtration

This study was carried out to evaluate the efficiency of conventional drinking water treatment processes with and without pre-oxidation with chlorine and chlorine dioxide and the use of granular activated carbon (GAC) filtration for the removal of diclofenac (DCF). Water treatment was performed using the Jar test with filters on a lab scale, employing nonchlorinated artesian well water prepared with aquatic humic substances to yield 20HU true color, kaolin turbidity of 70 NTU and 1mgL−1 DCF. For the quantification of DCF in water samples, solid phase extraction and HPLC–DAD methods were developed and validated. There was no removal of DCF in coagulation with aluminum sulfate (3.47mgAlL−1 and pH=6.5), flocculation, sedimentation and sand filtration. In the treatment with pre-oxidation and disinfection, DCF was partially removed, but the concentration of dissolved organic carbon (DOC) was unchanged and byproducts of DCF were observed. Chlorine dioxide was more effective than chorine in oxidizing DCF. In conclusion, the identification of DCF and DOC in finished water indicated the incomplete elimination of DCF through conventional treatments. Nevertheless, conventional drinking water treatment followed by GAC filtration was effective in removing DCF (⩾99.7%). In the oxidation with chlorine, three byproducts were tentatively identified, corresponding to a hydroxylation, aromatic substitution of one hydrogen by chlorine and a decarboxylation/hydroxylation. Oxidation with chlorine dioxide resulted in only one byproduct (hydroxylation).

Residue analysis of the pharmaceutical diclofenac in different water types using ELISA and GC-MS.

A highly sensitive and specific indirect competitive enzyme-linked immunosorbent assay (ELISA) for the determination of diclofenac in water samples was developed. With pure water, the limit of detection (LOD, S/N = 3) and IC50 were found to be 6 ng/L and 60 ng/L, respectively. The analytical working range was about 20-400 ng/L. Highest cross-reactivity (CR) of 26 tested pharmaceuticals, metabolites, and pesticides was found for 5-hydroxydiclofenac (100%). Other estimated values were well below 4% and, therefore, are negligible. The assay was applied for the determination of diclofenac in tap and surface water samples as well as wastewater collected at 20 sewage treatment plants (STPs) in Austria and Germany. Humic substances were identified as main interference in surface water. Wastewater samples which were only submitted to filtration and dilution yielded about 25% higher diclofenac concentrations using the ELISA compared to GC-MS. However, the ELISA turned out to be a simple, inexpensive, and accurate method for the determination of diclofenac both in influent and effluent wastewater after rather simple sample preparation, i.e., filtration, acidification, and readjustment to neutral pH-value, and at least 10-fold dilution with pure water.