Development of 8-4 Quadrupole Ion Guide to Suppress Sensitivity Loss in Clinical Mass Spectrometry

Hitachi, Ltd. and Hitachi High-Tech Corporation have developed an '8-4 Quadrupole Ion Guide' for clinical mass spectrometry, aiming to achieve both stable measurement of low-molecular-weight components with low blood concentrations, such as hormones and drugs, and stable operation of analytical devices required in testing centers and large hospitals. In mass spectrometry for liquid samples like blood, the amount of ions introduced from the device inlet determines sensitivity. While widening the inlet allows for more ions, it creates strong airflow that disrupts ion trajectories, preventing some ions from reaching the interior, and also allows neutral molecules and charged droplets to enter. This technology uses an electric field to separate ions from the airflow and focuses them in a position less affected by the airflow, allowing efficient introduction of target ions into the device. Verification results confirmed a transmission efficiency of 56% even at a gas flow rate of 5 L/min and demonstrated the separation of charged droplets and ions. Furthermore, the detection of testosterone at a low concentration of 1 pg/mL was confirmed. This contributes to reducing operational risks such as re-testing and device downtime by suppressing sensitivity loss. Part of these results will be presented at The 74th ASMS Conference on Mass Spectrometry and Allied Topics, to be held in San Diego, California, USA, from May 31 to June 4, 2026.