Open Probe Fast GC-MS for Medical Diagnostics and Real Time Drug Pills Analysis

Uri Keshet, Tel Aviv University, Tel Aviv, Israel (urikeshet@tau.ac.il)
Ramesh Bokka, Tel Aviv University, Tel Aviv, Israel
Alexander Fialkov, Tel Aviv University, Tel Aviv, Israel
Tal Alon, Tel Aviv University, Tel Aviv, Israel
Aviv Amirav, Tel Aviv University, Tel Aviv, Israel

Open Probe Fast GC-MS was developed for the provision of real time analysis without sample preparation, with separation, library identification and with the low cost MS of standard GC-MS. It is based on a heated probe oven that is mounted on a low thermal mass fast GC which is open to room air with helium purge flow protection to prevent air penetration. Open Probe fast GC-MS operation is simple: touch the sample with a sample holder, insert it into the Open Probe and start running GC-MS analysis with 30 s separation and 50 s for the start of next analysis. Accordingly, Open Probe Fast GC-MS serves as a viable alternative to ambient desorption ionization techniques such as DART, DESI, DSA and ASAP.

Drug pills analysis includes the following steps: A) The pill is broken by a gloved hand or wrapped in paper and crashed with a small hammer; B) The pill’s content is touched by a melting point vial; C) The melting point vial is inserted into the Open Probe; D) The start button is pressed and the GC-MS analysis takes 35 s plus 15 s cooling back to idle; E) During cooldown time the data is analyzed for the pill’s ingredients.

Over forty drug pills were analyzed including: a) Alprazolam in Xanax; b) Bisacodyl in a laxative drug pill; c) Terbinafine in an anti-fungal drug pill d) Sitagliptin in Janumet diabetes pill. Cannabis flowers were analyzed for their active ingredients Tetrahydrocannabinol and Cannabidiol.

This study further shows a possible new application of Open Probe Fast GC-MS in the medical diagnostics. Cholesterol and free fatty acids are analyzed in a droplet of blood, drawn using a diabetes finger pricker. The blood is touched by the melting point vial and inserted directly into the Open Probe for its real time analysis.