Rotating multitip micropillar array electrospray ionization-mass spectrometry for rapid analysis and high-throughput screening

The applications of rapid screening benzodiazepines from urine and determining synthetic reaction products and kinetics semi-quantitatively using a microfabricated rotating multitip electrospray ionization (ESI) platform for mass spectrometry (MS) is presented. The ESI tips are based on lidless micropillar array ESI (μPESI) sources where the transfer of liquid is based on capillary forces without external pumping. A single silicon platform contains 60 separate μPESI tips which can be individually used by rotating the whole platform by six degrees each time from tip to tip using a computer control. The rotating multitip μPESI platform with an ion trap mass spectrometer was successfully demonstrated in rapid identification and monitoring of intermediates and final products in chemical synthesis within 10 min. The system was also applied to high-throughput screening of benzodiazepines from urine samples. Urine samples were extracted with solid-phase extraction (SPE) using C18 phase ZipTip™ pipettes, enabling the use as small sample volumes as 50 μL of the urine sample. Therefore the whole sample treatment and the analysis with the rotating multitip μPESI-MS took only 5 min per sample.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (105 K)Download as PowerPoint slideHighlights► A microfabricated rotating multitip electrospray ionization platform for mass spectrometry. ► Rapid screening of benzodiazepines from urine with ZipTip extraction and μPESI/MS. ► Determination of synthetic reaction products on-line. ► Only very small volumes of samples are needed.