Miniature APCI ion source using AC corona discharge in a PFA tube: its application to the analysis of low-volatility compounds coupled with heat pulse desorption mass spectrometry (HPD/MS)

Abstract

DC corona discharge has long been used as the APCI ion source. In 2013, Habib et al. first proposed AC corona discharge as an APCI ion source and found that it is superior to DC as an ambient ion source [1]. In this study, an ion source using AC corona enclosed in a PFA (perfluoroalkoxy) tube (i.d.: 2 mm) was developed as a miniature APCI ion source coupled with heat pulse desorption mass spectrometry (HPD-MS) and used for the desorption of low-volatility compounds. Diverse materials were introduced, demonstrating the potential to apply the miniature ion source to gas-phase analytes, liquid samples, and solid materials in their native state. The modified technique was utilized in the analysis of a range of samples, including solid and liquid pharmaceuticals, food products, plant material, insects, and human biofluids, highlighting the wide applicability of the miniature APCI ion source across diverse sample types and fields of study.