Microscopy with Direct Analyte Probe Nanoextraction (DAPNe)-Coupled to Nanospray Mass Spectrometry for Localized Chemical Analysis of Document Inks

The proposed method is to develop a forensic science technique and instrumentation for the trace and ultra-trace analysis of inks, dyes, paints, and transferred chemistries on documents. This method would focus on direct sampling and microphase extraction of chemical residues to isolate and analyze key components present in inks and transfer on documents. This would be combined on a single package adapted to multiple platforms with broad range capabilities for the field of forensic science. The multistage workstation developed in our group has wide-ranging applications in the biological and chemical sciences. The workstation consists of a platform with 2-nano-positioners that hold end-effectors and capillaries used to manipulate, probe, and characterize objects of interest. The multistage workstation has been coupled to nanospray mass spectrometry allowing for precise and accurate analysis of trace chemical analytes, localized chemical extraction coupled with sub picomolar sensitivity (<100 attograms). We have demonstrated this technique by probing chemical residue (drugs and biological) from individual fibers, electrostatic lifts, and direct biological samples and analyzing them using nanospray mass spectrometry. Using a single instrument to manipulate, probe, and characterize an analyte minimizes the need of having multiple devices and instruments; this can transition simple microscopy into a localized chemical analyzer for document analysis. Extraction of chemical residue in combination with the document data (ie handwriting) can provide invaluable information that facilitates action for local police authorities in their investigations. This research can have a significant impact for trace analysts in the field of forensic science. The analysis of trace and ultra-trace residue within documents can provide evidence of other chemicals present that would normally be unseen or too difficult to detect with other instrumental methods or techniques. The analysis method can be conducted in a timely manner as to avoid extensive preconcentration methods that are time consuming in nature, and not cost effective. Chemical signature data from extracted residues exhibit high sensitivity and results are very reproducible to traditional methods of analysis. The transfer of trace samples collected from the documents to the laboratory would not be an issue in regards to the amount obtained as well as contamination of the sample from the environment. This method of analysis also has the potential to be deployable to any crime laboratory due to its multi platform nature, which would provide more immediacy toward obtaining results. Development will be accomplished in 3 - 6 month tasks listed below. The milestones are: -Task 1: Coupling of nanomanipulator to fit relevant microscopies, specifically Raman and IR for chemical localization, and for other unconventional spectro-microscopy techniques.. -Task 2: Characterize reproducibility, sensitivity, limits of detection for technique and develop direct SOP for handling document forensic evidence. -Task 3: Develop tip chemistry and methods for the analysis of paints, ink, paper chemistry and document analysis.. The total proposed budget will be $381K for the 24 month project window. Salary for the PIs and 2 research associates are included over the course of the award period ($158K). The IDC rate is set at 47% of supplies and salaries. Our group proposes to research a completely novel method and instrumental front-end to extract ultra-trace analytes (inks, paints, dyes) from various document matrices. This deliverable will be ideal for both archival and forensic science labs, and will be tested on trace and ultratrace chemicals pertaining to forensic science based analysis with local crime laboratories. ca/ncf