Blood Lipids Analysis for Medical Diagnostics with a BloodProbe and GC-MS with Cold EI

Benny Neumark, Chemistry, Tel Aviv University, Tel Aviv, Israel (benjaminn@mail.tau.ac.il)
Aviv Amirav, Chemistry, Tel Aviv University, Tel-Aviv Israel

Blood tests are widely used at hospitals worldwide while cholesterol and triglycerides analyses are estimated at about a billion analyses per year. Blood samples commonly appear as whole blood which is taken directly from the vein and in relatively large volume (approx. 30 ml). Such invasive approach can be painful and challenging when veins are damaged. The blood sample must undergo a time-consuming sample preparation, such as conversion into serum prior to analysis, and combined with lengthy analysis, getting results takes approximately 30 minutes. Moreover, results provided by currently used methods deliver limited information regarding the lipids and fat content in the sample.

We are developing a novel approach for minimally invasive, faster (approx. 10 minutes), raw-blood analysis with only 1 µL of blood. The preliminary results mass chromatograms provide rich lipids in blood information at the molecular level including the full range of fatty acids, cholesterol, cholesteryl esters, diglycerides, triglycerides, and drugs.

Using our newly developed BloodProbe, samples are collected by pricking the finger with a diabetes lancet and depositing the blood from the finger onto a melting point capillary vial. The melting point capillary vial is mounted into the BloodProbe and the raw-blood is analyzed without any sample preparation via thermal extraction for its medical diagnostics data.

The analysis is performed using GC-MS with Cold EI which is based on electron ionization (EI) of vibrationally cold molecules in supersonic molecular beams (SMB). The Cold EI mass spectra feature highly abundant molecular ions with extensive fragment information that results in identification with higher probabilities than what is received with standard EI spectra. In addition, the use of fly-through ion source eliminates any ion source degradation thus making GC-MS with Cold EI the ultimate instrument for fast and informative results.