Sugiyama Masuyuki, Hasegawa Hideki, Hashimoto Yuichiro
Hitachi Ltd., Tokyo, Japan.
Hitachi High-Tech Corporation, Ibaraki, Japan.
Rapid Commun Mass Spectrom. 2025 Dec 30;39(24):e10136. doi: 10.1002/rcm.10136.
Ion transmission efficiency from the atmospheric pressure ion source to the vacuum is critical for the sensitivity of mass spectrometers. In this study, we developed a novel conjugated octupole-quadrupole ion guide-the 8-4 pole ion guide-that achieves high transmission efficiency.
The dependence of signal intensity on parameters, including DC voltages, RF voltage applied to the 8-4 pole ion guide, and pressure within the ion guide, was measured. The transmission efficiency of the 8-4 pole ion guide was estimated from the ion current introduced into the ion guide and passing through the aperture downstream of the guide. The sensitivity of the mass spectrometer equipped with the 8-4 pole ion guide was evaluated using testosterone. Potential calculations and ion trajectory simulations were employed to better understand ion behavior within the 8-4 pole ion guide.
The dependence of signal intensity on pressure within the 8-4 pole ion guide suggests that the device achieves high ion transmission in the pressure range of 100-200 Pa. The ion current introduced into the 8-4 pole ion guide was 1.8 nA, while the ion current passing through the downstream aperture was 1.0 nA, resulting in a transmission efficiency of 56%. The mass spectrometer with the 8-4 pole ion guide achieved a coefficient of variation of 2.9% for 1 pg/mL testosterone. The lower limit of detection for testosterone was 0.12 pg/mL.
We successfully developed a novel 8-4 pole ion guide. The high transmission efficiency, demonstrated by ion current measurements, and the enhanced sensitivity of the mass spectrometer equipped with this ion guide indicate that it can maintain high transmission efficiency even under a high inlet gas flow of 5 L/min.
从大气压离子源到真空的离子传输效率对于质谱仪的灵敏度至关重要。在本研究中，我们开发了一种新型共轭八极 - 四极离子导向器——8 - 4极离子导向器，其实现了高传输效率。
测量了信号强度对参数的依赖性，这些参数包括直流电压、施加到8 - 4极离子导向器的射频电压以及离子导向器内的压力。根据引入离子导向器并通过导向器下游孔径的离子电流来估计8 - 4极离子导向器的传输效率。使用睾酮评估配备8 - 4极离子导向器的质谱仪的灵敏度。采用电位计算和离子轨迹模拟来更好地理解8 - 4极离子导向器内的离子行为。
信号强度对8 - 4极离子导向器内压力的依赖性表明，该装置在100 - 200 Pa的压力范围内实现了高离子传输。引入8 - 4极离子导向器的离子电流为1.8 nA，而通过下游孔径的离子电流为1.0 nA，传输效率为56%。配备8 - 4极离子导向器的质谱仪对1 pg/mL睾酮的变异系数为2.9%。睾酮的检测下限为0.12 pg/mL。
我们成功开发了一种新型8 - 4极离子导向器。通过离子电流测量证明的高传输效率以及配备该离子导向器的质谱仪灵敏度的提高表明，即使在5 L/min的高进气流下，它也能保持高传输效率。
