Tetrabutylammonium is a phase-transfer agent commonly used in PET radiochemistry. Its toxicity makes its quantification mandatory. However, the official HPLC method for tetrabutylammonium analysis reported in the European Pharmacopoeia (Ph. Eur.) apparently fails to achieve the described separation in most new generation reverse-phase columns. The study highlights the differences in separation achievable by varying some of the chromatographic conditions, such as temperature, eluent composition and ion-pairing agent concentration. In the end, variations to the method within the limits allowed by the Ph. Eur. were not sufficient to overcome the problem, thus forcing to a more radical change of the organic component of the mobile phase.

中文翻译：

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四丁基铵 HPLC 分析：Ph. Eur 的缺点。方法

四丁基铵是一种常用于 PET 放射化学的相转移剂。它的毒性使其定量成为强制性的。然而，欧洲药典 (Ph. Eur.) 中报道的用于四丁基铵分析的官方 HPLC 方法显然无法在大多数新一代反相柱中实现所述分离。该研究强调了通过改变某些色谱条件（例如温度、洗脱液成分和离子对试剂浓度）可实现的分离差异。最后，在 Ph. Eur 允许的范围内对方法进行更改。不足以克服这个问题，从而迫使流动相的有机组分发生更根本的变化。