Galantamine hydrobromide (GHB) is an anti-Alzheimer’s drug and a reversible acetylcholinesterase inhibitor. Two simple, sensitive and stability-indicating ultraviolet (UV) spectrophotometric methods were developed and validated for the determination of GHB in pharmaceuticals and a spiked human urine sample. In Method A, the absorbance of the GHB solution in 0.1 M acetic acid (HOAc) was measured at 293 nm. The drug exhibited the same absorbance maximum in 0.1 M hydrochloric acid (HCl), which served as the basis for Method B. Good linearity was ensured over the concentration range of 0.8–80 μg/mL GHB, with correlation coefficients of 0.9807 and 0.9988 for methods A and B, respectively, and the corresponding limits of detection were 0.1477 and 0.3082 μg/mL, while the limits of quantification were 0.4476 and 0.9340 μg/mL, indicating high sensitivity. The Sandell sensitivity values were calculated to be 0.1208 μg/cm2 for method A and 0.1175 μg/cm2 for method B. Accuracy and precision studies showed low relative error, and
This study aimed to develop a novel, rapid, and precise UV spectrophotometric method for quantifying Vonoprazan in both pure and tablet dosage forms. On the basis of an extensive evaluation of solubility, stability, toxicity, and carcinogenicity, and in line with eco-friendly approaches, a mixed phosphate buffer solution (pH 6.8) was employed as the solvent. Spectrophotometric analysis was performed within the 200–400-nm wavelength range. A distinct absorption maximum was identified at 237 nm, and strong linear relationship (r = 0.998) was observed, indicating compliance with Beer’s law within the 10–30 μg/mL concentration range. Furthermore, the recovery of Vonoprazan ranged from 98.01 to 101.25
This study outlines the development and validation of a simultaneous-equation method (Vierordt’s method) utilizing ultraviolet spectroscopy for the simultaneous estimation of ferulic acid and carnosic acid in bulk drugs. The technique assesses absorbance at 215 nm for ferulic acid and at 284 nm for carnosic acid. The method exhibited goodness of fit in the calibration curve in concentration ranges of 2–14 μg/mL for ferulic acid and 100–700 μg/mL for carnosic acid, with correlation coefficients of 0.9956 and 0.9976. Simultaneous equations for calculating the concentration of ferulic acid and carnosic acid in unknown samples were CFer = [A2(0.000529)–A1(0.000825)]/(–0.0000289) and CCarn = [A1(0.059398)–A2(0.038129)]/(–0.0000289), where A1 and A2 are the absorbance of the unknown sample solution at 215 and 284 nm, respectively. The recovery of ferulic acid and carnosic acid using the spiking method was 98–102
The present study describes the development and validation of QbD-assisted UV-Visible spectrophotometric methods for the quantitative determination of rizatriptan benzoate. The spectrophotometric determination was performed between 200–400 nm and the absorbance was compared to the wavelength. The developed method was validated according to the ICH guidelines for specificity, linearity, precision, accuracy, ruggedness, robustness, repeatability, forced degradation studies, and greenness assessment. The precision of the developed method was evaluated by calculating the percentage relative standard deviation (
For rapid quantitative detection of chlorpyrifos, an enhanced technique integrating colorimetric spectroscopy and chemometrics was created. Based on the molecular structure of chlorpyrifos, palladium chloride and resorcinol were selected as colorimetric reagents, with hydrochloric acid and acetic acid used as solvents for palladium chloride, respectively. Three distinct colorimetric systems were constructed to react with chlorpyrifos at varying concentrations. By comparing the absorbance spectra after the colorimetric reactions, the palladium chloride–acetic acid solution was idjentified as the most effective colorimetric reagent, capable of distinguishing absorbance signals for chlorpyrifos concentrations as low as 0.01 mg/kg. For 50 chlorpyrifos samples (0.01–88 mg/kg), the optimal model was selected by evaluating four key parameters: the determination coefficients of the calibration set ( R_c^2 ) and the prediction set ( R_p^2 ), together with the root mean square errors of calibration (RMSEC) and prediction cp (RMSEP). The partial least squares (PLS) regression model achieved R_c^2 = 0.9975, RMSEC = 1.3383 mg/kg, R_p^2 = 0.9948, and RMSEP = 1.8614 mg/kg. This sensitivity meets the detection limits specified for certain food products in the Chinese National Standard GB 2763-2021. The method is operationally safe, requires only 2 min for the colorimetric reaction, and provides a practical basis for developing detection instruments for other sulfur-containing organophosphorus pesticides.
