| Mass spectrometry (MS) profiling of small molecules in tissues and biofluids is a significant part of pharmaceutical development. However, tissue mass profiling by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI) has not been widely applied to small molecules because of matrix application and interference effects. Gas chromatrography coupled with electron ionization mass spectrometry (GC-MS) and liquid chromatography interfaced with ESI (LC-ESI MS) have been more extensively used for biofluid characterization. Recently we have introduced Nanostructure Initiator Mass Spectrometry (NIMS), a matrix-free platform for biomolecule analysis with minimal sample preparation. Here we show the potential of NIMS for clinical research and pharmacokinetics with xenobiotics: clozapine localized in rat brain tissue and ketamine detected directly from plasma and urine of anesthetized mice, without sample preparation. The hydrophobic properties of NIMS surface also allow in situ extraction and detection of xenobiotics such as diazepam, raclopride and nicotine from urine and saliva respectively. In addition, human breast cancer tissue sections were also analyzed revealing differences in the lipid profiles between the tumor and non-tumor regions. Overall, our results demonstrate the capacity of NIMS to perform sensitive, simple, fast and very low sample consuming analysis from highly complex biological matrices. |
