Atmospheric Pressure Photoionization (APPI) has emerged as a versatile ionization method in mass spectrometry, able to ionize compounds of comparably low ionization potential (typically -1 on APPI performance, evaluating the signal-to-noise ratios and detection limits achieved. Our findings indicate that reduced flow rates significantly improve sensitivity, demonstrating the potential to detect ultratrace levels of environmental pollutants with higher efficiency and lower background interference.
Tenhumberg et al. (Thu,) studied this question.