New method detects contaminants in heparin

University of Michigan researchers say they have demonstrated a simple, inexpensive method of detecting contaminants in the blood-thinning drug heparin.

Mark Meyerhoff said heparin is highly effective when used to prevent and treat blood clots in veins, arteries and lungs, but this year its reputation as a lifesaver was sullied when contaminated heparin products caused serious allergic reactions that led to a large number of deaths.

The new method, described in the journal Analytical Chemistry, relies on potentiometric polyanion sensors that were originally developed in the laboratory of Meyerhoff as a tool for detecting heparin in blood.

Meyerhoff and co-workers show that the disposable sensors also can be used to distinguish pure heparin from heparin tainted with small quantities of oversulfated chondroitin sulfate -- the culprit in the recent deaths.

"In this technique, the magnitude of the voltage you get from the sensing membrane is dependent on polyion charge density, and because the contaminant has a higher charge density than heparin, the method allows us to detect the contaminant in the presence of excess heparin," Meyerhoff said in a statement.

The new method is simpler and less expensive than analytical methods such as nuclear magnetic resonance and capillary electrophoresis, which have been suggested for detection of oversulfated chondroitin sulfate contaminants, Meyerhoff said.