Gadolinium-based contrast agents (GBCA) are widely used to enhance tissue contrast during magnetic resonance imaging (MRI) procedures. However, free Gadolinium (Gd) is undesirable as a drug substance, due to its high toxicity. Consequently, a coordinating ligand is required to keep it in solution and to increase tolerance. In order to achieve an adequate performance, GBCA must be administered in relatively large amounts. Chelate amounts are around 13–20 g and for Gd alone, this may amount to 3.3 g. Taking into account the route of administration, impurities in GBCA may be significant. Gadolinium occurs in nature along with 16 other elements known collectively as rare earth metals (RE), which are found throughout the earth's crust in minerals such as monazite. Gadolinium oxide corresponds to 0.7–4.0% of the RE present in minerals, and the sum concentration of RE in minerals is around 4%. Rare earth metals are difficult to separate, as the chemical and physical properties of one RE are significantly similar to those of others. In this study, the presence of other RE in GBCA formulations was investigated. Different lots of Magnevist®, Viewgam®, OptiMARK®, Omniscan®, Dotarem®, and Gadovist® were analyzed. Inductively-coupled plasma mass spectrometry and atomic absorption spectrometry were used for RE determination. Procedure optimization included sample decomposition and method validation for element determination. The results showed that Sc, Y, La, Ce, Pr, Nd, Eu, Tb, Tm, Dy, Ho, and Er were present in the 22 samples analyzed. Terbium, Thulium, Europium, and Lanthanum were, on average, found in the highest amounts, which were 0.42 mg/L, 0.17 mg/L, 0.17 mg/L, and 0.16 mg/L, respectively. These results could be attributed to the similarity among Europium, Gadolinium, and Terbium. They are in sequence in the periodic table and therefore present very close ionic radii, restricting their separation. Considering the sum of all RE, Viewgam® was the most contaminated formulation (mean of 2.16 mg/L) and Magnevist® the least (mean of 0.64 mg/L). Although the RE are chemically similar, the other RE do not perform as Gd as a contrast agent; therefore, their presence in formulations may be a matter of concern.

d基造影剂（GBCA）被广泛用于在磁共振成像（MRI）程序中增强组织对比度。然而，由于游离high（Gd）具有高毒性，因此不希望用作药物。因此，需要配位配体将其保持在溶液中并增加耐受性。为了获得足够的性能，必须相对大量地管理GBCA。螯合物的含量约为13–20 g，仅Gd的含量就可能达到3.3 g。考虑到给药途径，GBCA中的杂质可能很重要。nature与天然存在的16种其他元素一起被称为稀土金属（RE），稀土元素在独居石等矿物中遍布整个地壳。氧化oxide相当于矿物质中RE的0.7-4.0％，矿物质中RE的总浓度约为4％。稀土金属很难分离，因为一种稀土的化学和物理性质与其他稀土的化学和物理性质非常相似。在这项研究中，研究了GBCA配方中其他RE的存在。分析了不同批次的Magnevist®，Viewgam®，OptiMARK®，Omniscan®，Dotarem®和Gadovist®。电感耦合等离子体质谱和原子吸收光谱法用于稀土元素的测定。程序优化包括样品分解和用于元素测定的方法验证。结果表明，在所分析的22个样品中存在Sc，Y，La，Ce，Pr，Nd，Eu，Tb，Tm，Dy，Ho和Er。found 、,、 Euro和镧的平均含量最高，分别为0.42 mg / L，0.17 mg / L，0.17 mg / L和0.16 mg / L，分别。这些结果可以归因于Euro，Ga和Ter之间的相似性。它们在周期表中顺序排列，因此离子半径非常接近，限制了它们的分离。考虑到所有可再生能源的总和，Viewgam®是受污染最严重的配方（平均值为2.16 mg / L），而Magnevist®则是最少的（平均值为0.64 mg / L）。尽管RE在化学上相似，但其他RE不能作为Gd用作造影剂。因此，它们在配方中的存在可能是一个令人关注的问题。16 mg / L）和最少的（平均0.64 mg / L）。尽管RE在化学上相似，但其他RE却不像Gd那样用作造影剂。因此，它们在配方中的存在可能是一个令人关注的问题。16 mg / L）和最少的（平均0.64 mg / L）。尽管RE在化学上相似，但其他RE不能作为Gd用作造影剂。因此，它们在配方中的存在可能是一个令人关注的问题。