title: Evaluation of in vivo solid phase microextraction for minimally invasive analysis of nonvolatile phytochemicals in Amazonian plants.
abstract: BACKGROUND
  Although solid phase microextraction (SPME) has been used extensively for fingerprinting volatile compounds emitted by plants, there are very few such reports for direct insertion SPME. In this research, direct contact of SPME probes with the interstitial fluid of plants was investigated as a method for phytochemical analysis.
  
  
  OBJECTIVE
  Medicinal plants from the Amazon have been the source of numerous drugs used in western medicine. However, a large number of species used in traditional medicine have not been characterized chemically, partly due to the difficulty of field work. In this project, the phytochemical composition of plants from several genera was fingerprinted by combining convenient field sampling by solid phase microextraction (SPME) with laboratory analysis by LC-MS. The new method was compared with classical sampling followed by liquid extraction (LE).
  
  
  METHODS
  SPME probes were prepared by coating stainless steel wires with a mixture of polyacrylonitrile and either RP-amide or HS-F5 silica particles. Sampling was performed by inserting the microextraction probes into various tissues of living plants in their natural environment. After in vivo extraction, the probes were sealed under vacuum and refrigerated until analyzed. The probes were desorbed in mobile phase and analyzed on a Waters Acquity UPLC with triple quadrupole mass spectrometer in positive ion mode.
  
  
  RESULTS
  Twenty Amazonian plant species were sampled and unique metabolomic fingerprints were obtained. In addition, quantitative analysis was performed for previously identified compounds in three species. Comparison of the fingerprints obtained by in vivo SPME with those obtained by LE showed that 27% of the chromatographic features were unique to SPME, 57% were unique to LE, and 16% were common to both methods.
  
  
  CONCLUSIONS
  In vivo SPME caused minimal damage to the plants, was much faster than traditional liquid extraction, and provided unique fingerprints for all investigated plants. SPME revealed unique chromatographic features, undetected by traditional extraction, although it produced only half as many peaks as ethanol extraction.
authors: Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY 12208, USA. Electronic address: marcel.musteata@acphs.edu.
authors: Florin Marcel
authors: FM
authors: Musteata
authors: Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY 12208, USA; Center for Research on Amazonian Natural Products, Universidad Nacional Agraria de la Selva, CIPNA-UNAS, Av. Universitaria, Tingo María, Peru.
authors: Manuel
authors: M
authors: Sandoval
authors: Herbarium Amazonense, Faculdad de Ciencias Biológicas, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru.
authors: Juan C
authors: JC
authors: Ruiz-Macedo
authors: Botanical Dimensions, PO Box 807, Occidental, CA 95465, USA.
authors: Kathleen
authors: K
authors: Harrison
authors: Center for Spirituality and Healing, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
authors: Dennis
authors: D
authors: McKenna
authors: Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY 12208, USA.
authors: William
authors: W
authors: Millington
mesh_terms: D010568:Peru; D064209:Phytochemicals / Q000032:analysis*; D010946:Plants, Medicinal / Q000737:chemistry*; D032069:Psychotria / Q000737:chemistry*; D052617:Solid Phase Microextraction; D030014:Tabernaemontana / Q000737:chemistry*
chemical_list: D064209:Phytochemicals
keywords: Amazonian plants; LC-MS; Phytochemical fingerprinting; Quantitative analysis; Solid phase microextraction