Journal of Chemical Metrology Articles

Standardized analytical methods for determining elemental concentrations require thorough validation and estimation of measurement uncertainty. Inductively coupled plasma optical emission spectrometry (ICP-OES) is a widely used technique for multielement analysis with the ASTM E2941-14 standard specifying the analytical conditions for its application. This study aims to validate the ICP-OES method and estimate the expanded uncertainty for multielement determination in accordance with ASTM E2941-14. Method validation and uncertainty estimation were conducted following Eurachem (2014) and Eurachem-CITAC (2012) guidelines, respectively. The method demonstrated acceptable linearity, with coefficients of determination (R2) ranging from 0.9972 to 1.0000 and correlation coefficients (R) from 0.9982 to 1.0000, exceeding the acceptance criterion (R2/R ≥ 0.995). Accuracy under repeatability conditions showed coefficients of variation between 1.0% and 8.0%, indicating good consistency. Trueness evaluation revealed no significant bias, with recovery rates within the acceptable range of 100% ± 10%. Combined uncertainty values ranged from 0.0425 (silver; Ag) to 0.5156 (scandium; Sc), corresponding to relative uncertainties of 1.25% to 8.16%, respectively. Expanded uncertainties ranged from 0.0850 (Ag) to 1.0312 (Sc). The dominant sources of relative uncertainty were associated with calibration curve-based concentration measurements and volumetric equipment.

This study optimized the extraction of sesamin and 4-hydroxy-sesamin from Cinnamomum camphora residue, yielding 0.3804 % under conditions of 86 ℃, 43 min, and a 1:8.39 solid-liquid ratio. The purified compounds showed 67.86 % and 78.87 % recovery rates via recrystallization. In LPS-induced BV-2 microglia, 4-hydroxy-sesamol (10-40 μmol/L) activated autophagy, reduced iNOS, COX-2, IL-6, IL-1β, TNF-α mRNA expression, and demonstrated neuroprotection without cytotoxicity, suggesting its potential in mitigating neuroinflammation.

Abstract: There is no universal method and validation parameters for leachable studies for potential impurities in a metered-dose inhalation drug in the pharmaceutical industry, and this study aims to develop a new method to determine the leachability analysis of some fatty acids (myristic, linoleic, palmitic, oleic, elaidic, stearic and arachidic acids) by HPLC/CAD that may leach from the valve portion of the product as potential impurities in metered dose inhalers. The method was found suitable for leachability analysis of fatty acids in metered dose inhalation medication by HPLC/CAD by changing the method parameters, instrument, and detector settings and validated by determining sensitivity, linearity, range, specificity, accuracy, and recovery. In the developed analytical method, the C18 column was found to be suitable as the stationary phase for chromatographic separation, and mobile phase components were determined to be a gradient system consisting of mobile phase A (0.5 mL formic acid in 1000.0 mL pure water) and mobile phase B (0.5 mL formic acid in 1000.0 mL acetonitrile). The standard solution was stable for 48 hours at 10°C and the sample solution was stable for 3 hours at 10°C. This study will fill an important gap in the determination of the leachability of the valve part of inhalation products and will make an important contribution to the evaluation of the effectiveness of packaging and storage systems in quality assurance processes in pharmaceutical products.