Fast Whole Blood Analysis for Medical Diagnostics by GC-MS with Cold EI

Benny Neumark, Tel-Aviv University, Tel-Aviv, Israel (benjaminn@mail.tau.ac.il)
Oneg Elkabets, Tel-aviv University, Tel-aviv, Israel
Gabi Shefer, The Institute Of Endocrinology, Metabolism And Hypertension, Tel-aviv Sourasky Medical Center, Ichilov Hospital, Tel-aviv, Israel
Asaf Buch, The Institute Of Endocrinology, Metabolism And Hypertension, Tel-aviv Sourasky Medical Center, Ichilov Hospital, Tel-aviv, Israel
Naftaly Stern, The Institute Of Endocrinology, Metabolism And Hypertension, Tel-aviv Sourasky Medical Center, Ichilov Hospital, Tel-aviv, Israel
Aviv Amirav, Tel-aviv University, Tel-aviv, Israel

Blood tests are widely used for medical diagnostics at hospitals worldwide and require relatively large volumes (3-30 ml). Taking blood from the veins can be painful and challenging. Currently, blood samples are not analyzed as is, and getting results can take over an hour. Moreover, the results obtained deliver limited information.

GC-MS with Cold EI is based on interfacing the GC and MS with supersonic molecular beams (SMB) along with electron ionization of vibrationally cold sample compounds in the SMB, in a contact-free fly-through ion source (hence the name Cold EI). We developed a BloodProbe which is a modified ChromatoProbe that accommodates a 10 cm thin glass rod. Using a micropipette, 2µl blood samples were taken directly from the donors’ fingers and deposited on the glass rod of the BloodProbe. The samples were analyzed as is using GC-MS with Cold EI equipped with a ChromatoProbe.

The fast, less than 10 minutes, analysis results show non-polar lipids and the full range of free fatty acids, cholesterol, cholesteryl esters, vitamin E, monoglycerides, diglycerides, triglycerides, and drugs. Each of them was detected at the molecular level. Our whole blood analysis was characterized by and revealed:

1.      Analysis was informative as the analysis of blood serum.

2.      We found a major enhancement of several fatty acid methyl esters in the blood of a cancer patient with liver dysfunction compared with the blood of healthy patients.

3.      Cholesteryl esters were more sensitive than free cholesterol alone to the effect of the diet of fat people.

4.      We discovered elemental sulfur as S₈ in whole blood, which varied in its concentration among people but not yet in a clear fashion.

5.      We found vitamin E as both α-tocopherol and β-tocopherol.

6.      Results show the presence of drugs such as caffeine and ibuprofen (originated in Advil capsule).

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Short Biography of Presenting Author

Ph.D. student in Prof. Aviv Amirav’s research group at Tel Aviv University. Focusing on developing new analytical chemistry instrumentation and applications using GC-MS with Supersonic Molecular Beams.