Shimadzu has produced an application note describing the analysis of toxic elements in supplements as per USP 2232 using its ICPMS 2030.
Introduction
The United States Pharmacopeia (USP) 2232 designates permitted daily exposure (PDE) levels for four elements for which toxicity is a concern in dietary supplements. PDE values need to be converted to concentrations when evaluating metallic impurities in formulations or their structural components. Compliance with these regulations is also obligatory for supplements imported to the U.S. from other nations. Here, a quantitative analysis performed on arsenic, cadmium, mercury, and lead in supplements using the Shimadzu ICPMS-2030 ICP mass spectrometer is presented.
Sample Preparation
Four commercially available supplements were used. The microwave digestion method was chosen as it could decompose samples faster than the typically used wet digestion method. Since this method uses a closed vessel, it also has the advantage that loss of volatile elements such as arsenic is minimal.
Instrumentation
The Shimadzu ICPMS-2030 mass spectrometer was used for measurements. In addition to providing high sensitivity, the ICPMS-2030 is equipped with a collision system using helium gas, which reduces interference from argon and chlorine significantly.
Analysis
The calibration curve method was used for quantitative analysis of the elements arsenic, cadmium, mercury, and lead. To verify the analysis results, a spike recovery test sample was created by adding a standard solution of measurement elements after the sample decomposition. Quantitative analysis was performed in the same way using this sample.
Results and Conclusion
Favourable recovery rates were achieved and confirm that the results obtained were appropriate. The sensitivity was also evidently sufficient, even at the maximum intake of 10 g per day. Using the ICPMS-2030, it is possible to perform an analysis for controlling the heavy metals arsenic, cadmium, mercury, and lead in supplements.
