Dear Reader,

Welcome to the latest issue of Prosolia News. We are continuously striving to bring you the latest news and information from Prosolia, Inc. In this issue, learn about the latest applications using DESI-MS.

Dried Blood Spot Analysis by DESI-MS: Rapid Assessment of Xenobiotics in Whole Blood

The collection and analysis of whole blood spotted onto filter paper has been utilized in neonatal screening for in-born errors of metabolism for nearly 40 years and has more recently been investigated as a sample collection method for pharmacokinetic (PK) and toxicokinetic (TK) studies for use during clinical trials. Dried blood spots (DBS) offer the inherent advantages of requiring smaller blood volumes for analysis, simpler sample handling, and convenience in storage and shipment to laboratories. The ability to utilize smaller blood volumes is particularly advantageous for PK and TK preclinical studies. Traditionally, TK studies are performed using plasma and require blood volumes between 100 and 500 µL to be taken from a single animal. Due to physiological and ethical limitations of serial sampling from small rodents where total circulating blood volumes can be only 12-15mL, composite sampling is performed which leads to an increased number of animals being used per study. The use of DBS samples for preclinical PK and TK studies improves the quality of data by enabling serial bleeds to be taken from the same animal allowing significant reduction in the number of animals/study, resulting in cost benefits.

Direct desorption/ionization methods present some compelling advantages, in terms of simplicity of the analytical method through elimination of extensive sample preparation and potentially high sample throughput. The feasibility for utilizing desorption electrospray ionization (DESI) for the direct analysis of DBS samples has been recently presented at the 57th ASMS Conference in Philadelphia, PA. See WOB pm 03:30 - ’ÄúDesorption Electrospray Ionization (DESI) for Direct Quantitation of Xenobiotics from Dried Blood Spots;’Äù by Dr. Christopher A. Evans et al. of GlaxoSmithKline.

The combination of DBS sampling and direct analysis using DESI has several advantages:

1. Ease of sample handling, storage and shipment of biological specimens;
2. No further sample preparation is required;
3. Analysis times are significantly reduced resulting in reduced method development times.

The summation of these advantages results in significant cost savings in the bioanalytical workflow.

Analysis of Post Blast Pipe Bomb Fragments Using DESI-MS

Prosolia, Senior Scientist, Joseph Kennedy presented his most recent application and poster at the 57th ASMS Conference in Philadelphia, PA. The presentation described the application of DESI-MS to the analysis of post blast debris from home-made pipe bombs for the presence of residual explosive residue.

An important facet of counterterrorism is the collection of data from post-blast fragments in order to determine the type and composition of the explosive device used. Pipe bombs are easily assembled due to accessibility of explosive materials such as such black powder substitutes (e.g. Hodgdon Pyrodex® Pellets and Triple Seven® Powder). Most current techniques for analysis of post-blast fragments involve rinsing the different fragments with solvent followed by analysis by a separation technique or spectroscopy. These techniques are time consuming and are not currently suitable for field analysis. Desorption Electrospray Ionization (DESI) combined with mass spectrometry was used to analyze different surfaces directly and is ideally suited for analysis of post-blast pipe bomb fragments.

Mass spectra were collected in positive and negative ion mode. An Omni Spray® 1-D automated DESI Ion Source (Prosolia) and Thermo LTQ ion trap mass spectrometer with 80/20/0.1 acetonitrile / water/ formic acid as the spray solvent was used to analyze the pipe bomb fragments directly without solvent

Aug. 30 - Sept. 4, 2009, IMSC,
Bremen, Germany
If you are attending the International Mass Spectrometry Conference in Bremen, Germany, please stop by our booth to learn more about Omni Spray® Ion Sources and DESI. Also, don't miss the opportunity to review and discuss the new applications presented by Prosolia Director of Research, Dr. Justin Wiseman and Senior Scientist, Joseph Kennedy. Presentations at IMSC will focus on the analysis of drugs of abuse - such as cocaine - in different matrices using filter paper as a collection device.

extraction. The mass spectra were compared to data from standard mixtures of the powders. Regions of the pipe bomb fragments believed to contain explosive residue were identified visually. Ten millimeter sections of the different fragments from pipe bombs were scanned and known residual inorganic and organic components from Pyrodex® Pellets and Triple Seven® Powder were identified.

Pipe bombs were assembled using different materials (glass, PVC, and metal pipe) with Pyrodex® Pellets and Triple Seven® Powder. After detonation, fragments from the different pipe bombs were collected and analyzed. The mass spectra from the three surfaces indicated differences in the component composition related to the different powders used in the pipe bombs.

Based on the component analysis, the data confirmed that DESI’ÄêMS can be used to qualitatively identify different explosive materials used in making pipe bombs and distinguish between different black powder substitutes.

For the full application note, poster and results, please visit our website at www.prosolia.com.

Prosolia’Äôs Omni Spray¬Æ Ion Source featuring DESI technology provides direct measurements of samples in the areas of life sciences, pharmaceutical, forensics, materials, environmental, and security.

Note: Hodgdon Pyrodex® Pellets and Triple Seven® Powder are registered trademarks of Hodgdon Powder Company.