質量分析法による測定のための内部標準としての重水素化アルカンスルホン酸の容易な合成と分析的応用

Alkanesulfonates are widely used as anionic surfactants in detergents, requiring accurate quantitative methods for quality control. This study aimed to develop a deuterated internal standard for sodium alkanesulfonates via hydrogen/deuterium (H/D) exchange using a transition metal catalyst. Generally, sulfonate groups are known to strongly adsorb onto metal surfaces and deactivate catalysts due to their catalyst-poisoning effect. However, we found that alkanesulfonates can be deuterated with a ruthenium on carbon (Ru/C) catalyst in D₂O under a hydrogen atmosphere. The D contents increased with alkyl chain length, ranging from 20 to 86%. Sodium dodecanesulfonate, which showed the highest D content, was selected as the internal standard. A model detergent sample was prepared to evaluate quantification performance. Quantitative analysis was conducted using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) with electrospray ionization (ESI) and field desorption (FD)-TOFMS. ESI provided high sensitivity for trace analysis, while FD offered faster measurements for concentrated samples. Spike-and-recovery experiments across a concentration range (0.50-200 ppm) demonstrated that using an internal standard improved measurement accuracy. This approach offers a practical solution for quantifying sulfonate-based surfactants in complex detergent matrices.