Spectrophotometric Determination Research Articles

Porphyrin-Grafted Poly(ethylene terephthalate) as a Reusable and Highly Selective Colorimetric Probe for Mercuric Ion Contaminants in Aqueous Samples.

Heavy metals are the most hazardous water pollutants, with severe health and environmental consequences. Among these, mercuric (Hg2+) ions are known to cause detrimental health issues in both humans and aquatic life. Due to this, several analytical techniques have been devised to detect and quantify the amount of this ion. However, most of these require advanced instrumentation, prolonged analysis time, and sample preparation. In this study, a low-cost and highly reusable colorimetric probe was developed by grafting porphyrin to poly(ethylene terephthalate) sheets using an oxazoline polymer as covalent adhesive. Upon exposure to trace amounts of Hg2+ in solution, the fabricated material visually transitioned from faint brownish pink to green by the complexation mechanism. Additionally, the transparency of this probe allowed the quantitative spectrophotometric determination of the Hg2+ concentration in aqueous samples. It was also shown that the material is highly stable, which can be reused for more than 50 times without significant decline in its performance, hence, making it suitable for the onsite monitoring of mercuric ion contamination in different bodies of water.

De Novo DNM1L Mutation in a Patient with Encephalopathy, Cardiomyopathy and Fatal Non-Epileptic Paroxysmal Refractory Vomiting

Mitochondrial fission and fusion are vital dynamic processes for mitochondrial quality control and for the maintenance of cellular respiration; they also play an important role in the formation and maintenance of cells with high energy demand including cardiomyocytes and neurons. The DNM1L (dynamin-1 like) gene encodes for the DRP1 protein, an evolutionary conserved member of the dynamin family that is responsible for the fission of mitochondria; it is ubiquitous but highly expressed in the developing neonatal heart. De novo heterozygous pathogenic variants in the DNM1L gene have been previously reported to be associated with neonatal or infantile-onset encephalopathy characterized by hypotonia, developmental delay and refractory epilepsy. However, cardiac involvement has been previously reported only in one case. Next-Generation Sequencing (NGS) was used to genetically assess a baby girl characterized by developmental delay with spastic–dystonic, tetraparesis and hypertrophic cardiomyopathy of the left ventricle. Histochemical analysis and spectrophotometric determination of electron transport chain were performed to characterize the muscle biopsy; moreover, the morphology of mitochondria and peroxisomes was evaluated in cultured fibroblasts as well. Herein, we expand the phenotype of DNM1L-related disorder, describing the case of a girl with a heterozygous mutation in DNM1L and affected by progressive infantile encephalopathy, with cardiomyopathy and fatal paroxysmal vomiting correlated with bulbar transitory abnormal T2 hyperintensities and diffusion-weighted imaging (DWI) restriction areas, but without epilepsy. In patients with DNM1L mutations, careful evaluation for cardiac involvement is recommended.

Simultaneous deep eutectic solvent based microextraction of Allura Red and Brilliant Blue in violet-purple foodstuffs

A vortex-assisted simultaneous deep eutectic solvent based microextraction and spectrophotometric determination method was established for the first time to simultaneously monitor Allura Red and Brilliant Blue in violet-purple foodstuffs. A ternary deep eutectic solvent was created using benzoic acid, tetra butyl ammonium bromide and benzyl alcohol at 1:1:3mol ratio. The method variables including pH, volume of deep eutectic solvent and vortex time were optimized by Box-Behnken design of response surface methodology. The limits of detection were determined to be 25 and 9µg/L for Allura Red and Brilliant Blue, respectively. The linear dynamic ranges of the method were obtained between 82-12000 and 29-4200µg/L for Allura Red and Brilliant Blue, respectively. Preconcentration factor of the method was obtained as 15. Greenness evaluation was performed using Analytical GREEnness tools. Extraction mechanisms affecting quantitative simultaneous microextraction of the target dyes were explained. The developed method was validated with high-performance liquid chromatography analysis. Analyte addition-recovery tests were also applied to confectionery samples to validate the proposed method and determine the dye contents of foodstuffs. Allura Red and Brilliant Blue contents of violet-purple confectioneries were determined between 3.85-74.59 and 4.02-26.11µg/g concentrations with 94.5-98.6% and 93.0-101.0% recoveries, respectively.

SIMPLEX OPTIMIZATION FOR THE SPECTROPHOTOMETRIC DETERMINATION OF AZITHROMYCIN DRUG VIA ION-PAIR FORMATION

A spectrophotometric determination of azithromycin was optimized using the simplex model. The approach has been proven to be accurate and sensitive. The analyte has been reacted with bromothymol blue (BTB) to form a colored ion pair which has been extracted in chloroform in a buffer medium of pH=4 of potassium phthalate. The extracted colored product was assayed at 415 nm and exhibited a linear quantification range over (1 - 20) g/ml. The excipients did not exhibit any interferences with the proposed approach for assaying azithromycin in pharmaceutical formulations.

Novel eco-friendly spectrophotometric determination of lercanidipine hydrochloride in tablets using methyl red

The aim of the work was to develop a simple, eco-friendly, quick, affordable and alternative spectrophotometric procedure that uses the azodye methyl red (MR) for the determination of lercanidipine in its dosage form considering the “green” chemistry principles. Materials and methods. Analytical equipment: Shimadzu UV-1800 double beam UV-visible spectrophotometer (Japan) with included UV-Probe 2.70 software, RAD WAG AS 200/C precise analytical balance (Poland), Elmasonic EASY 40H ultrasonic bath. Lercanidipine hydrochloride (purity 99 %) was purchased from Jiyan Chemicals (India). Lercanidipine tablets 10 mg and 20 mg were used in our experiments. Results and discussion. To determine the amount of lercanidipine in tablets, a spectrophotometric method has been developed. To select the best dye for the method development, we tested a variety of dyes, including MR, bromocresol purple, bromophenol blue, cresol red, bromocresol green and bromothymol blue. We selected MR as the reagent based on the experimental studies' outcomes, and the solvent was an acetonitrile and ethanol mixture with a ratio of 95 to 5. The optimal parameters were determined for the quantitation of lercanidipine in tablets utilizing MR with 5×10-5 mol/L of dye concentration, 0.5 ml of MR solution, at a temperature of 25 °C without heating; detection wavelength was 498 nm and reaction time of 5 min. By using the molar ratios (saturation) method and Job's (continuous variations) approach, the stoichiometric coefficients of reacting components involving lercanidipine and dye were established to be 1:1. The proposed spectrophotometric procedure was linear within the concentration ranging from 6.48 – 32.41 μg/mL. Using the least squares method, a regression equation was generated: y = 0.0208x – 0.0318. The correlation coefficient was higher than 0.999, indicating that the analytical procedures' linearity is acceptable; the limit of detection and limit of quantitation were 1.19 μg/mL and 3.62 μg/mL, respectively. The robustness, accuracy and precision of the study results fell within acceptable limits. The proposed method was successfully applied to determine the content of lercanidipine in its tablet dosage forms. The analysis of the method's "greenness" using AGREE and GAPI tools yielded excellent results. Conclusions. The method that has been developed can serve as an alternative approach for the routine control of lercanidipine content in its tablets

Spectrophotometric Determination of Sulfamethazole Drug by Using Azo Coupling Reaction

Spectrophotometric Determination of Sulfamethazole Drug by Using Azo Coupling Reaction

Indirect Spectrophotometric Determination of Antidepressant Drugs by Oxidation Using Ponceau 4R Dye

A simple and sensitive indirect spectrophotometric method is developed for the assay of Adrenaline, Dopamine hydrochloride, and Methyldopa in their pure and pharmaceutical preparations. The method is based on the principle of oxidation of the above drugs with a known amount of the oxidizing agent, N-bromosuccinimide (NBS), in hydrochloric acid. The unreacted oxidant bleaches Ponceau 4R dye, then the absorbance of the remaining dye (ΔA) is measured at 507 nm. The method obeyed Beer’s law within the concentration range of 3.5-10, 4-15, and 5-20 μg/mL, with molar absorptivity values of 8.01×104, 5.32×104, and 4.93×104 L. mol-1cm-1 for Adrenaline, Dopamine hydrochloride and Methyldopa, respectively. The recovery ranged between 99.15 to 100.61%, and the relative standard deviation (RSD) was less than 1.42 % for all drug compounds. The method was applied successfully to pharmaceutical preparations for the studied medicinal compounds from different origins, as its results were in good agreement with the original content of the drugs in their pharmaceutical formulations and with the standard addition procedure, which proved that there was no interference by the excipients.

Development of a transcutaneous form of desloratadine

Development of a transcutaneous form of desloratadine

Validation of the Miniaturized Spectrophotometric Determination of Organic Carbon and Phosphorus in Soils

ABSTRACT The developments and innovations in green miniaturized technologies suggest that a complete miniature approach (MA) to determine organic carbon (OC) and phosphorus (P) in soils may enable handling a large number of samples. In comparison to the conventional approach (CA), this approach also reduces waste generation and analysis costs. Here we have miniaturized all the steps of the conventional analytical procedures for OC and P analysis and carried out an in-depth validation of MA on various aspects, including linearity, biases, precision, inaccuracy, and imprecision. This rigorous assessment aimed to delineate the effect of miniaturization on the quality of determination along with its associated benefits and limitations. The findings revealed a strong correlation between the MA and CA in the OC test, indicating an R2 >0.84, with the Deming regression producing a model equation demonstrating a highly significant slope and an intercept closely approximating zero. Similarly, the p values obtained by MA and CA exhibited a correlation with an R2 > 0.99, alongside the Deming regression displaying a minimal intercept and a slope approaching one. The Bland–Altman analysis indicated a mean bias of 0.01 (95% CI, −0.51 to 0.54) for OC values and −1.7 (95% CI, −9.04 to 5.57) for p values. This cross-validation study highlights the applicability and limitations of the MA in estimating OC and P levels across a diverse range of soils.

The Effect of Neuronal CoQ10 Deficiency and Mitochondrial Dysfunction on a Rotenone-Induced Neuronal Cell Model of Parkinson's Disease.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder currently affecting the ageing population. Although the aetiology of PD has yet to be fully elucidated, environmental factors such as exposure to the naturally occurring neurotoxin rotenone has been associated with an increased risk of developing PD. Rotenone inhibits mitochondrial respiratory chain (MRC) complex I activity as well as induces dopaminergic neuronal death. The aim of the present study was to investigate the underlying mechanisms of rotenone-induced mitochondrial dysfunction and oxidative stress in an in vitro SH-SY5Y neuronal cell model of PD and to assess the ability of pre-treatment with Coenzyme Q10 (CoQ10) to ameliorate oxidative stress in this model. Spectrophotometric determination of the mitochondrial enzyme activities and fluorescence probe studies of reactive oxygen species (ROS) production was assessed. Significant inhibition of MRC complex I and II-III activities was observed, together with a significant loss of neuronal viability, CoQ10 status, and ATP synthesis. Additionally, significant increases were observed in intracellular and mitochondrial ROS production. Remarkably, CoQ10 supplementation was found to reduce ROS formation. These results have indicated mitochondrial dysfunction and increased oxidative stress in a rotenone-induced neuronal cell model of PD that was ameliorated by CoQ10 supplementation.

Spectrophotometric determination of celecoxib and tramadol in the new approved formulated dosage form using principle component regression assistive model

Celecoxib and tramadol have been combined in a novel FDA-approved medication to address acute pain disorders requiring opioid treatment when other analgesics proved either intolerable or ineffective. The absorbance spectra of celecoxib and tramadol exhibit significant overlap, posing challenges for their individual quantification. This study introduces a spectrophotometric quantification approach for celecoxib and tramadol using a principle component regression assistive model to assist resolving the overlapped spectra and quantifying both drugs in their binary mixture. The model was constructed by establishing calibration and validation sets for the celecoxib and tramadol mixture, employing a five-level, two-factor experimental design, resulting in 25 samples. Spectral data from these mixtures were measured and preprocessed to eliminate noise in the 200–210 nm range and zero absorbance values in the 290–400 nm range. Consequently, the dataset was streamlined to 81 variables. The predicted concentrations were compared with the known concentrations of celecoxib and tramadol, and the errors in the predictions were evidenced calculating root mean square error of cross-validation and root mean square error of prediction. Validation results demonstrate the efficacy of the models in predicting outcomes; recovery rates approaching 100 % are demonstrated with relative root mean square error of prediction (RRMSEP) values of 0.052 and 0.164 for tramadol and celecoxib, respectively. The selectivity was further evaluated by quantifying celecoxib and tramadol in the presence of potentially interfering drugs. The model demonstrated success in quantifying celecoxib and tramadol in laboratory-prepared tablets, producing metrics consistent with those reported in previously established spectrophotometric methods.

Spectrophotometric determination of cobalt ions in water using bimetallic chemosensor based on sulfa drug azo dye

AbstractA spectrophotometric technique has been developed for detection of cobalt(II) ions in aqueous solution samples utilising a new chemosensor. This technique relies on the formation of a stable yellow-orange complex at pH = 13 using 4-(2-Hydroxy-naphthalen-1-ylazo)-N-thiazol-2-yl-benzenesulfonamide (H2L) as ligand through complexation with Co(II) ions. At λ = 390 nm, complex absorption was detected. A correlation coefficient of 0.9934 indicated linearity in the concentration range of (1.7–8.4 × 10–5 mol L−1). The limit of detection (LOD) and limit of quantification (LOQ) were assigned to be 0.147 µg ml−1 (2.5 µmol L−1) and 0.489 µg ml−1 (8.3 µmol L−1),respectively. The stoichiometric composition of the complex, which is 2:1 of M:L, was confirmed by the correlation between the continuous variation results and the molar-ratio methods proposed by Job. Additionally, the structure of the solid complex that is produced when H2L reacts with Co(NO3)2.6H2O has been determined by applying different spectroscopic and analytical techniques, confirming the formation of the complex in the same molar ratio as that determined by Job’s method. The geometrical structure of the complex was confirmed to be tetrahedral by a combination of magnetic moment results and UV-Vis spectra.

Chromatographic and Spectrophotometric Determination of Clindamycin in Pharmaceutical Products

Accurate, precise, and reliable chromatographic and spectrophotometric methods were developed for determining clindamycin (CLD) in pharmaceutical formulations. The spectrophotometric method was adopted for flow injection analysis (FIA). The method is based on the online oxidation of CLD and measuring the absorbance of the resulting product using a flow cell at 605 nm. Experimental conditions, including FIA variables and reaction conditions, were optimized. The chromatographic separation was achieved using a C8 column and an isocratic mobile phase. The composition of the mobile phase selected for the analysis consists of a mixture of phosphate buffer (50%), MeOH (35%), and ACN (15%), adjusted to a pH of 3.47 by phosphoric acid. The eluent was monitored with a UV detector at 205 nm. The linearity range was 10–200 and 50–800 µg/mL for the FIA and HPLC, respectively. The applicability of the FIA and HPLC methods was validated by analyzing CLD in synthetic and commercial pharmaceutical products. No significant interferences were observed from the common excipients usually used in commercial formulations.

Indopolycarbocyanine dyes as perspective analytical reagents for spectrophotometric determination of nitrite by radical nitration

A spectrophotometric method for the quantitative determination of nitrite was developed, based on the radical nitration of indopolycarbocyanine dyes in the presence of 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO). The rate of the reaction of the studied dyes with nitrite increases with the lengthening of the polymethine chain and the presence of hydrophilic sulfo groups in the side chain of the dye. TEMPO acts as a co-reagent, significantly accelerating the reaction rate and increasing the sensitivity of nitrite determination. The proposed reaction mechanism is supported by spectrophotometric and HPLC/MS studies. For Ind2 (tetramethine indocarbocyanine cationic dye), the limit of detection for nitrite is 0.50 µM within a linearity range of 1–13 µM. The developed method is sensitive, with a LOD 130 times lower than the maximum contaminant level (MCL) of nitrite in drinking water (65 μM), as specified by the WHO. The method is of low-toxicity and good selectivity, as the determination of nitrite is not significantly affected by the main components of water. The method was successfully applied for the analysis of nitrite in natural and bottled water.

Spectrophotometric Determination of Total Phosphorus in Fresh Water Using Ammonium Molybdate

Spectrophotometric Determination of Total Phosphorus in Fresh Water Using Ammonium Molybdate

A Spectrophotometric Determination of Amlodipine Drug in Pharmaceutical Preparations Using 2, 6-Dihydroxybenzoic Acid Reagent

In this study, a delicate, exact, and efficient colorimetric spectrophotometric technique was created for the assessment of Amlodipine in its unadulterated structure and in drug arrangements The strategy depends on the response of the optional amine in the medication with the carbonyl gathering in the natural reagent 2, 6 dihydroxy benzoic corrosive within the sight of p-dimethyl amino benzaldehyde to frame a yellow complex (Manich complex). The greatest absorbance was viewed as at 402 nm. Linearity was seen in the scope of 2-40 μg/mL, and the connection coefficient was viewed as 0.9909. The molar absorptivity was viewed as 1.392 × 104 L•mol-1•cm-1. It was observed that the shade of the item was steady and no massive change in absorbance was noticed for as long as 50 minutes a recuperation of 100.596% was gotten. The restriction of discovery (LOD) and cutoff of evaluation (LOQ) were viewed as 0.968 µg/mL and 3.228 µg/mL, individually. The %RSD was 4.32, which demonstrates the precision of the proposed strategy.

From Extraction to Stabilization: Employing a 22 Experimental Design in Developing Nutraceutical-Grade Bixin from Bixa orellana L.

Bixin is the main carotenoid found in the outer portion of the seeds of Bixa orellana L., commercially known as annatto. This compound is industrially employed in pharmaceutical, cosmetic, and food formulations as a natural dye to replace chemical additives. This study aimed to extract bixin from annatto seeds and obtain encapsulated bixin in a powder form, using freeze-drying encapsulation and maltodextrin as encapsulating agent. Bixin was extracted from annatto seeds employing successive washing with organic solvents, specifically hexane and methanol (1:1 v/v), followed by ethyl acetate and dichloromethane for subsequent washes, to effectively remove impurities and enhance bixin purity, and subsequent purification by crystallization, reaching 1.5 ± 0.2% yield (or approximately 15 mg of bixin per gram of seeds). Bixin was analyzed spectrophotometrically in different organic solvents (ethanol, isopropyl alcohol, dimethylsulfoxide, chloroform, hexane), and the solvents chosen were chloroform (used to solubilize bixin during microencapsulation) and hexane (used for spectrophotometric determination of bixin). Bixin was encapsulated according to a 22 experimental design to investigate the influence of the concentration of maltodextrin (20 to 40%) and bixin-to-matrix ratio (1:20 to 1:40) on the encapsulation efficiency (EE%) and solubility of the encapsulated powder. Higher encapsulation efficiency was obtained at a maltodextrin concentration of 40% w/v and a bixin/maltodextrin ratio of 1:20, while higher solubility was observed at a maltodextrin concentration of 20% w/v for the same bixin/maltodextrin ratio. The encapsulation of this carotenoid by means of freeze-drying is thus recognized as an innovative and promising approach to improve its stability for further processing in pharmaceutical and food applications.

Machine learning approaches for simultaneous spectrophotometric determination of heavy metal ions in water samples

In this study, the simultaneous determination of Co, Cd, Ni, Cu, and Pb was carried out as a color complex with 4-(2-pyridylazo) resorcinol in an aqueous solution under the assesting of machine learning. A partial least-squares multivariate linear regression and artificial neuron network for the analysis of mixtures of metals were developed. MATLAB is a powerful software machine learning program that was used to support matrix calculations and displays. The benefit of MATLAB in the construction of the machine learning model allows the development of a rapid and highly effective analysis of multiple components in the mixtures without separation and enrichment. For individual determinations, the working ranges were discovered as the important information for choosing the initial concentration of each heavy metal in a mixture, r. The results of analysis of Ni2+, Pb2+, and Cd2+ by two methods Partial Least Squares - PLS and Artificial Neural Networks - ANN are sensitive and accurate for simultaneous determination of the concentration of these ions in the synthesis mixture with a high regression coefficient of 0.993, respectively, 0.997, 0.997 for Ni2+, Pb2+ and Cd2+. As for Cu2+ and Co2+, the accuracy is higher when using the ANN method.

Green DES based microextraction method for monitoring brilliant black BN (E151) in diverse food matrices

A green deep eutectic solvent (DES) based microextraction method was established for separation and spectrophotometric determination of E151 in food matrices. DES composed of tetra pentyl ammonium bromide and 1-octanol (1:5) was used. Important analytical microextraction parameters including pH, volume of DES and time of vortex mixing were optimized using Box-Behnken design of Response Surface Methodology. The other variables including composition ratio of DES and sample volume were optimized by one variable at a time optimization process. The method exhibited linear behaviour for E151 having concentration range between 132–12000 µg/L with 30 preconcentration factor. The relative standard deviation, detection limit and quantitation limit were determined to be 5 %, 40 and 132 µg/L, respectively. The scores of analytical greenness and applicability for the method were determined to be 0.69 and 62.5, respectively. pK values of E151 were determined. Extraction mechanisms of E151 were elucidated. The method was applied to foodstuffs and water samples to determine their E151 contents by analyte addition recovery tests with recovery values ranging between 94–103 %.

Utility of Localized Surface Plasmon Resonance of Gold Nanoparticles for Spectrophotometric Determination of Dobutamine in Pharmaceutical Formulations

Utility of Localized Surface Plasmon Resonance of Gold Nanoparticles for Spectrophotometric Determination of Dobutamine in Pharmaceutical Formulations