Jeanita S. Pritchett1;  Jeffrey A. Lawrence2, Karen W. Phinney3; and Jennifer R. Verkouteren2

National Institute of Standards and Technology

1. Chemical Sciences Division

2. Materials Measurement Science Division

3. Biomolecular Measurement Division

The availability of standards that can be used to help confirm the identity of drugs of abuse continues to be a challenge for forensic laboratories, particularly in the area of designer drugs.  A limited number of standards are available commercially, and even fewer standards can be obtained as certified reference materials (CRMs).  Hence, laboratories are often faced with preparing in-house reference standards, either by chemical synthesis or through isolation of the desired compound from seized materials.  The desire is to develop a mechanism to provide cost effective, easy to use standards for seized drug analysis by GC-MS or LC-MS(/MS).  The proposed work employs inkjet printing technology to deposit known amounts of pure substances onto an inert surface via picoliter sized droplets.  At the time of use, the compound is desorbed from the surface by rinsing with a small amount of solvent.  To assess the feasibility of this technique, nominal masses of methamphetamine (10 ng, 50 ng, and 500 ng) were deposited onto Whatman® dried blood spot cards (DMPK-IND-B) from 100 ng/µL solutions with the highest extraction efficiency observed for 500 ng deposition.  Furthermore, the stability of the printed compounds on different substrates stored under various storage conditions was investigated.  It was determined that it was possible to efficiently recover (> 80%) and analyze nanogram amounts of methamphetamine from Whatman® dried blood spot cards and through LC-MS and GC-MS analysis.  Furthermore, we found that the samples were most stable at subambient temperatures. The potential advantages of this approach relative to current practices include the fact that only a very small amount of the compound is needed for each printed standard, and the printed standards could be considered as single use materials, so that any potential contamination from multiple uses of the same batch of material is eliminated.  Future investigation will involve deposition of synthetic cannabinoids and cathinones  through inkjet printing as well as direct printing into GC vials to simplify the sample preparation process.