INTRODUCTION: The presence of impurities in the radiolabeling can result in undesirable labeled molecules that may affect the diagnostic. The United States Pharmacopoeia reviewed the subject in the general chapter and established the limits for some metal impurities that need to be controlled in pharmaceuticals and introduced inductively coupled plasma as tool for quality control.

OBJETIVE: The aim of this work was to perform determination of 27 trace metals by inductively coupled plasma optical emission spectrometry (ICP-OES) in 18F-FDG labeled molecule.

EXPERIMENTAL: The measurements were carried out using a Vista MPX simultaneous ICP-OES with axially viewed plasma. The 100 ppm multielementar standard solution containing Ag, Al, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe, Ga, Li, K, Mg, Mn, Na, Ni, Pb, Mo, Pd, Se, Sr, Te, Tl, Zn was used for obtaining the calibration standard solution were prepared with 3% v/v concentrated HNO3. To assess the influence of the matrix effect on the results, the diluted sample of the radiopharmaceutical was spiked with a o,5ppm concentration of each metal for determination of recovery. 18F-FDG was diluted up to 1:40 with purified water. Several batches were analyzed in triplicate.

RESULTS: The main impurities observed were Al (5.72 ppm), B (0.92 ppm), K (1.99 ppm) anda Pb (1.2 ppm). The recoveries of the elements were in the acceptable range of 98-116%, except K, which presented 138% of recovery.

CONCLUSION: The procedure described in this work was fast, accurate and showed to be an effective method to determine trace impurities without interferences. No previous treatment reaction was necessary, reducing the analysis time and costs when compared to other tachniques