DETERMINATION OF SOME TRACE AMOUNT OF RARE EARTH ELEMENTS IN MEAT AND ORGANS FROM PIG FEEDED WITH FOOD CONTAINING RARE EARTHS BY ICP-MS TECHNIQUES

Abstract

In this report, the trace amount of some rare earth impurities in meat and some organs sample from pig
feeded with rare earth food additive was determined by inductively coupled plasma mass spectrometry
(ICP-MS). The signal suppression effect of the sample matrix on the signals of the REE was effectively
compensated for using 103Rh internal standard. The grounded samples were subjected to microwave acid
digestion as reported by TCVN-9525:2018. Briefly, 0.5 g of the sample was mixed to 2.0 mL of 65%
HNO3 and 1.0 mL of 30% H2O2 in microwave polytetrafluoroethylene digestion vessels. The microwave
digestion system was operated at 400W (medium power mode) for 12 min. The method of detection limits
(LOD) were in the range of 0.004 µg/kg to 0.018 µg/kg. The sample recovery was obtained between 97.0
and 107.3 % by the certified reference material (CRM-BCR-668). La, Ce, Pr, Nd, and total REEs content
were assessed. The La, Ce content in some pig organs samples (liver, heart, spleen, kidney) using rare
earth food additive were higher than the reference samples about two to three times, and in the meat
sample were negligible.