ICP-OES elemental impurities study on different pharmaceutical dosage forms of Ibuprofen using microwave-assisted digestion procedure

Fast and simple closed-vessel microwave-assisted digestion procedure was developed for decomposition of three pharmaceutical dosage forms of ibuprofen such as tablets, suspension and gel, prior to elemental impurity analysis by one robust and precise ICP-OES method. Samples were digested by four-step microwave program consisting of a 10 min temperature gradient to 180°C, maintained at 180°C for 10 min, followed by 5 min ramping time to 210°C with holding time of 10 min on 210°C. Subsequently, ICP-OES method was developed and validated for simultaneous determination of selected elemental impurities. Results of recovery studies range between 77% and 105% for each element in all analyzed formulations. Correlation coefficients of the regression equations were higher than 0.999 for all analyzed elements. Validation results reveal that the proposed method is specific, accurate, and precise and could be applied for simultaneous quantitative analysis of multi element solutions in different pharmaceutical dosage forms of ibuprofen.

Elemental Analysis of Medicinal Plant Moringa stenopetela leaves by Atomic Absorption Spectroscopy

The purpose of the current study is to analyze the concentration levels of selected trace metals: Ca, Cu, Fe, K and Zn in medicinal plant Moringa stenopetala grown in SNNPR, Ethiopia. A wet digestion procedure is used. Thus, the result showed that the concentrations of Ca, Cu, Fe, K and Zn in Moringa stenopetala grown in Gamo Gofa (Arbaminch) were;2.80±0.36, 0.866±0.134, 7.98±1.23, 3.02±0.63 and 84±0.92 mg/Kg, in Wolaita 3.28±0.28, 0.94±0.16, 7.13±1.32, 7.13±1.32 and 0.61±0.11mg/Kg and in Konso were; 2.97±0.67, 0.77±0.098, 6.79±0.73, 2.39±0.23 and 0.37±0.006mg/Kg respectively.

Extraction of Cu, Fe, Mn, and Ni from Margarine Samples Using Extraction Induced by Emulsion Breaking Procedure Prior to Graphite Furnace Atomic Absorption Spectrometry and Comparison of Results to Provisional Tolerable Daily Intake Values

Background The emulsion induced by emulsion breaking (EIEB) procedure was previously reported for the extraction of copper, iron, manganese, and nickel from liquid oil samples such as vegetable oil. Objective To optimize the EIEB procedure for determination of copper, iron, manganese, and nickel in solid oil (margarine) samples by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Methods The extraction procedure uses a surfactant in nitric acid to form an emulsion followed by heating to break the emulsion. Optimization included variation of the test portion size, the type and concentration of the surfactant, the concentration of nitric acid in the aqueous solution, the emulsion agitation time, heating temperature, and the time required to break the emulsion. Results Mean element concentrations of 11 margarine samples were in the following ranges: Cu 0.031–0.131 µg/g, Fe 5.7–24.9 µg/g, Mn 0.542–1.11 µg/g, and Ni 0.108–0.134 µg/g. Under the optimized extraction conditions, the detection limits (µg/kg) were 4.8, 13, 1.5, and 23 for Cu, Fe, Mn, and Ni, respectively. The accuracy of the extraction procedure was determined by comparison to commonly used microwave digestion procedure. The EIEB results were not statistically different from the microwave digestion results when analyzed by GFAAS as determined by the statistical tests. Conclusions The EIEB procedure was shown to be equivalent to the commonly used microwave digestion procedure for extraction of analytes from margarine samples. Highlights The optimized EIEB extraction procedure is simple, rapid, low cost, and environmentally friendly. It has improved detection limits and allows calibration with aqueous standards.

Comparison of Microwave-Assisted Digestion and Consensus Open-Vessel Digestion Procedures for Evaluation of Metalliferous Airborne Particulate Matter

Metal occupational exposure limits mainly focus on total content of the respective metals of interest. The methods applied for trace metal analysis in occupational health and safety laboratories are usually standardized to pragmatic consensus digestion schemes, ensuring comparability of results. The objective of the present study entailed the evaluation of a recently developed HNO3-only microwave-assisted digestion procedure by comparison with the German consensus hot-block digestion and other national digestion schemes. An inter-laboratory comparison test with participation of nine national occupational health and safety laboratories from Europe and North America was organized. For adequate emulation of what workers are at risk of inhaling four different industrial metal processing workplace dusts (electronic recycling, high-speed steel grinding, cylinder head cleaning, and battery combustion ash) were homogenized and sieved to the particle size < 100 µm diameter at IFA. The participants were asked to process air sample-typical amounts according to the German hot-plate technique, the IFA microwave-assisted digestion scheme as well as their national or in-house conventional digestion method for airborne dust and analyze for Cd, Co, Cr, Co, Fe, Mg, Ni, Pb, and Zn. Recoveries (relative to consensus open-vessel digestion) obtained for the new IFA microwave-assisted digestion were between 88 and 114% and relative reproducibility standard deviations were <10% for most metals of interest. The in-house digestion procedures applied varied widely but (whether microwave, hot block, or open vessel) yielded comparable results for the predominantly elemental alloy type dusts supplied. Results become more diverse for the combustion dust, especially if a combination of microwave-assisted digestion procedures with high temperatures and hydrofluoric acid is applied. ISO 15202-2 is currently being revised; this digestion procedure will be included as a possible variant in annex 2.