Paper spray ionization mass spectrometry: recent advances and clinical applications.

INTRODUCTION: Paper spray mass spectrometry has provided a rapid, quantitative ambient ionization method for xenobiotic and biomolecule analysis. As an alternative to traditional sample preparation and chromatography, paper spray demonstrates the sampling ionization of a wide range of molecules and significant sensitivity from complex biofluids. The amenability of paper spray with dried blood spots and other sampling types shows strong potential for rapid, point-of-care (POC) analysis without time-consuming separation procedures. Areas covered: This special report summarizes the current state and advances in paper spray mass spectrometry that relate to its applicability for clinical analysis. It also provides our perspectives on the future development of paper spray mass spectrometry and its potential roles in clinical settings. Expert commentary: Paper spray has provided the fundamental aspects of ambient ionization needed for implementation at the POC. With further clinical management and standardization, paper spray has the potential to replace traditional complex analysis procedure for rapid quantitative detection of illicit drugs, therapeutic drugs and metabolites. Surface and substrate modifications also offer significant improvement in desorption and ionization efficiencies, resulting in enhanced sensitivity. Comprehensive analysis of metabolites and lipids will further extend the implementation of paper spray ionization mass spectrometry into clinical applications.