Elemental Impurity Detection Technique in Fluorodeoxyglucose (¹⁸F) Using Inductively Coupled Plasma Mass Spectrometry: Development and Validation

INTRODUCTION. When developing and validating manufacturing of a product, Russian radiopharmaceutical manufacturers are required to detect ubiquitous impurities (Pb, As, Fe as well as other elements) causing contamination. At the stage of preliminary monitoring, Al, Cu, and Zn were found to most often contribute to fluorodeoxyglucose (¹⁸F) elemental contamination.

AIM. This study aimed to develop and validate a technique detecting Al, As, Cu, Fe, Pb, and Zn in fluorodeoxyglucose (¹⁸F) using inductively coupled plasma mass spectrometry (ICP-MS).

MATERIALS AND METHODS. The technique was developed on a model mixture simulating fluorodeoxyglucose (18F). A sample with minimum analysed impurities was used for validation; then varying amounts of standard analyte solutions were added. The content was determined using Agilent 7900 mass spectrometer. Signal intensities of the following isotopes (a.u.m.) were recorded: ²⁷Al, ⁵⁷Fe, ⁶³Cu, ⁶⁶Zn, ⁷⁵As, and ²⁰⁸Pb.

RESULTS. The organic matrix was found to insignificantly affect elemental analysis. Due to matrix effect, NaCl reduced spike recovery of Al, Cu, Pb, and Zn to the level below 70%. When diluting model mixture tenfold, spike recovery of the analytes reached 90–101%. Correlation coefficients of element concentration — signal intensity linear dependences for the analytes exceeded 0.99. When estimating precision, RSD values did not exceed 10%.

CONCLUSIONS. A technique has been developed detecting Al, As, Cu, Fe, Pb, and Zn in fluorodeoxyglucose (¹⁸F) using ICP-MS. This technique considers influence of matrix components on quantification of target elements when preparing samples. Validation parameters of the technique comply with pharmacopoeial requirements.

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