Neocuproine-Based Sensitive Flow Injection Method for Mefenamic Acid Determination in Aqueous Solutions and Pharmaceutical Formulations

Introducción: Se presenta un enfoque novedoso y preciso para la estimación del ácido mefenámico (MEF) en for-mulaciones farmacéuticas y soluciones acuosas, utilizando espectrofotometría de inyección de flujo. Del mismo modo, este método demuestra un alto nivel de sensibilidad y precisiónMétodo: Se basa en la reducción del complejo Cu (II)-2,9DMP a complejo Cu (I)-2,9DMP coloreado, mediante dos pasos de reacción. Sin embargo, en el primer paso se produce la reacción entre la neocuproína y el Cu (ΙΙ) para for-mar un complejo incoloro de Cu (II) -2,9DMP, y en el segundo paso el ácido mefenámico redujo el complejo incoloro formado a Cu (I) - 2,9DMP con color amarillo anaranjado, se desarrolló y validó el método de inyección de flujo.Resultados: La medición de la densidad óptica de las sustancias amarillo-naranja se realizó a una longitud de onda de 454 nm. Los gráficos de calibración muestran linealidad dentro de los rangos de concentración especificados de 1,00-80,00 μg / ml. El límite de detección (LOD) se determina en 0,360 μg/ml, mientras que el límite de cuantifi-cación (LOQ) se encuentra en 1.093 μg/ml.Conclusiones: la metodología propuesta exhibió atributos notables como rapidez, sensibilidad y confiabilidad, lo que la hace adecuada para la cuantificación precisa de (MEF) en formulaciones farmacéuticas y soluciones acuosas en diversas formulaciones disponibles comercialmente. (AU)

Introduction: A novel and precise approach is presented for the mefenamic acid (MEF) estimation in pharmaceuti-cal formulations and aqueous solutions, utilizing flow injection spectrophotometry. Similarly, this method demon-strates a high level of sensitivity and accuracy.Method: The suggested method is based on the reducing of Cu(II)-2,9DMP complex to coloured Cu(I)- 2,9DMP com-plex ,by two step of reaction. However, in the first step the reaction is occur between neocuproine and Cu(ΙΙ) to form colorless complex of Cu(II)-2,9DMP, then in second step mefenamic acid reduced the formed colorless complex to Cu(I)- 2,9DMP with yellow orange colour, Flow Injection Method were developed and validated.Results: The measurement of the optical density of the yellow-orange substances was conducted at a wavelength of 454 nm. The calibration graphs exhibit linearity within the specified concentration ranges of 1.00-80.00 μg/mL. The detection limit (LOD) is determined to be 0.360 μg/ mL, while the limit of quantification (LOQ) is found to be 1.093 μg/ mL.Conclusions: the proposed methodology exhibited notable attributes such as rapidity, sensitivity, and reliability, rendering it suitable for the accurate quantification of (MEF) in pharmaceutical formulations and aqueous solutions in various commercially available formulations. (AU)

Natural Iraqi palygorskite clay as low cost adsorbent for the treatment of dye containing industrial wastewater.

In this study, natural Iraqi low- cost locally available clay (palygorskite) was studied for its potential use as an adsorbent for removal Congo red from aqueous solutions. Batch type experiments were conducted to study the effect of contact time, initial pH of the dye solution, initial dye concentration, adsorbent dosage, and particle size of adsorbent on adsorption capacity of Congo red. The adsorption occurred very fast initially and attains equilibrium within 60 min. When the effect of pH of solution dye on the yield adsorption has been carried in a range of 2-10, the adsorption obtained was nearly the same with very slightly effect of pH and it was reported that above 49.07 mg/g of Cong red by palygorskite clay occurred in the pH range 2 to 10. It was observed that the removal of Congo red increase with increasing initial dye concentration and adsorbent dose, but, adsorption capacity decrease with increasing adsorbent dose. The adsorption capacity increase with decreasing particle size of adsorbent. The equilibrium adsorption data were interpreted using Langmuir and Freundlich isotherm models. The obtained results revealed that the equilibrium data closely followed both models, but the Langmuir isotherm fitted the data better. The maximum adsorption capacity was found to be 99 mg/g at ambient temperature. Results indicate that Iraqi palygorskite clay could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of colour and dyes.