New automated and high-throughput quantitative analysis of urinary ketones by multifiber exchange-solid phase microextraction coupled to fast gas chromatography/negative chemical-electron ionization/mass spectrometry

Abstract

The present research is focused on automation, miniaturization, and system interaction with high throughput for multiple and specific Direct Immersion-Solid Phase Microextraction/Fast Gas Chromatography analysis of the urinary ketones. The specific Mass Spectrometry instrumentation, capable of supporting such the automated changeover from Negative Chemical to Electron Ionization mode, as well as the automation of the preparation procedure by new device called MultiFiber Exchange, through change of the fibers, allowed a friendly use of mass spectrometry apparatus with a number of advantages including reduced analyst time and greater reproducibility (2.01-5.32%). The detection limits for the seven ketones were less than 0.004 mg/L. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative Mass Spectrometry fragmentation patterns together with the chromatographic separation and software automation are also investigated.

Figure 1

XYZ autosampler equipped with 3-position trays MultiFiber Exchange and SPME Fast Fit Assembled.

Figure 2

Processing using MFX/XYZ autosampler.

Figure 3

Derivatization time for ketone-PFBHA-oximes at 25°C.

Figure 4

Extraction efficiency for liquid phase SPME fibers.

Figure 5

Fast GC/MS chromatogram of the organic ketone derivatives by EI (Figure 5(a)) and NCI (Figure 5(b)) mode.

Figure 6

Fast GC/MS chromatogram of the BOHO-/AcAc-TBDMS by EI mode.