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Workshops & seminars

Metal-assisted LDI for high resolution imaging MS
Dr. Pierre Chaurand(Universite de Montreal)

DATE & TIME
Friday, November 2, 2018
3 p.m. – 4:30 p.m.
SPEAKER(S)

Dr. Pierre Chaurand

COST

This event is free

Website

WHERE

Richard J. Renaud Science Complex
7141 Sherbrooke W.
Room SP-157

WHEEL CHAIR ACCESSIBLE

Yes

Title:  Matrix-free metal assisted LDI methods are developed for the imaging MS (IMS) of targeted lipid compounds with high specificity and high sensitivity. Neutral lipids play key roles in cellular membranes, signaling and energy storage. In particular, cholesterol, fatty acids and triglycerides play significant roles in the development of life-style associated diseases. We have explored the analysis of these compounds by high-resolution laser desorption ionization IMS using metal layers directly deposited on tissue sections.

From the investigation of various tissue specimens, using silver-assisted LDI IMS we have thus far mapped and identified several compounds including, cholesterol, arachidonic acid and docosahexaenoic acid. While both fatty acids and cholesterol show great affinity for silver, other molecules such as triglycerides have strong affinities for other selected cations. For this purpose, the coupling of sodium salts and sputtered gold has been developed to enhance both desorption and ionization yielding a 30-fold signal increase of triglycerides (TAG) compared to standard MALDI MS approaches. Although this method targets TAGs, we have also detected and imaged several other compounds including cholesterol esters, which are hard to detect by MALDI MS. These novel imaging MS strategies are being used to study atherosclerosis, Alzheimer’s and non-alcoholic fatty liver diseases.


Silver-assisted IMS has also shown to be a powerful tool in forensic science for the analysis of fingermarks left on various surfaces, such as paper, cardboard, plastic and forensic lifting tape, by combining the suspect identification and the detection of numerous endogenous and exogenous compounds. Several cosmetics and personal care products were detected and imaged in fingermarks, generating a unique chemical signature of its owner. Further we showed that common illicit drugs (tetrahydrocannabinol, cocaine and heroin) found during investigations can be detected and imaged in fingermarks. The methodology also allows to successfully identify and image traces of blood in fingermarks.

Bio:  Pierre Chaurand (Ph.D. 1994, Université Paris Sud, Orsay, France) is Professor of Chemistry at the Université de Montréal (2009 - present). His expertise’s are in fundamental and analytical mass spectrometry. He is one of the pioneers of the imaging mass spectrometry (IMS) technology. His research interests are focused on the development of new strategies and methods to improve the specificity and sensitivity of IMS with applications in clinical biology. Pr. Chaurand has over 100 peer reviewed publications and book chapters in the field of MS, with over 50 in the specific field of IMS.

 

Dr. Chaurand is the guest of Dr. Dajana Vuckovic

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