Elemental Analysis of Pharmaceutical Products for Chronic Kidney Disease by High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry (HR–CS GFAAS)

Abstract

Here is reported the development of methods for the determination of Al, Cd, Cu, Mo, and Pb by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR–CS GFAAS) after microwave-assisted acid digestion in pharmaceuticals for patients with chronic kidney disease. The measurements were performed at the primary lines of the analytes. The optimum pyrolysis and atomization temperatures were 1800 and 2700 °C for Al, 600 and 1600 °C for Cd, 1400 and 2200 °C for Cu, 1400 and 2600 °C for Mo and 900, and 2400 °C for Pb, respectively. Palladium was used as a chemical modifier for Pb, while Mg(NO₃)₂ was employed for Al, Cd, and Cu. The validation parameters (linearity, analytical range, accuracy, precision, limit of quantification, and specificity) were obtained according to the stipulations in the Chapter American Pharmacopeia <233>. The limit of detection was 1.63 μg L⁻¹ for Al, 0.02 μg L⁻¹ for Cd, 0.49 μg L⁻¹ for Cu, 0.76 μg L⁻¹ for Mo, and 0.59 μg L⁻¹ for Pb. The precision was between 2.1% for Mo and 8.1% for Al. The recoveries were from 90.2% for Pb to 106.1% for Cd. The developed methods were successfully applied to determine the five analytes in 50 pharmaceutical formulations. Cadmium, Cu, and Mo concentrations were within the maximum limits recommended by the Brazilian Pharmacopeia in all medicines. However, six drug products had a Pb concentration higher than the limit for this element. All samples analyzed showed relatively high concentrations of Al.

KEYWORDS:

• Chronic kidney disease
• elemental impurity
• high-resolution continuum source graphite furnace atomic absorption spectrometry (HR–CS GFAAS)
• pharmaceuticals

Additional information

Funding

We acknowledge CAPES (Coordination for the Improvement of Higher Education Personnel) for its financial support.