On-stage liquid-phase lipid microextraction coupled to nanospray mass spectrometry for detailed, nano-scale lipid analysis.

Rationale: Developments in instrumentation aimed at microscopic sampling have led to an emphasis on applications analyzing small volumes and molecular concentrations within biological, chemical, and industrial samples. Simultaneous improvements in the sensitivity and versatility of nanospray mass spectrometers have made it possible to directly couple these sampling and analysis processes.

Methods: We developed a versatile liquid-phase lipid microextraction (LPME) technique for nanoliter to microliter volumes that is amenable to direct nanospray mass spectrometry (NMS).