Archive for August, 2009

CCC purification of drugs from messy bio-matricies

Wednesday, August 19th, 2009

I’ve just read about an exciting new application for CCC. Our friends at Abbott, Jill Hochlowski, Jeffrey Pan, Philip Searle, Wayne Buck and Stephen Spanton, have taken advantage of one of the key benefits of the liquid stationary phase for ADME studies (absorption, distribution, metabolism, excretion). ADME studies involve looking for minor constituents in very complex biological matrices. A major obstacle for HPLC in doing ADME studies is that there is no assurance of complete recovery of the starting sample, on the contrary you will almost certainly lose some material due to permanent absorption on the silica (not to mention possible loss of material that can occur while you are preparing the sample for injection). CCC on the other hand has the advantages of requiring little to no sample prep and most importantly 100% recovery of even the most minor constituents.

For their application an automated CCC system was prepared with an on-line MS in addition to the standard UV detection.  This allowed for definitive identification of target material during the run.

The article “Purification of drugs from biological fluids by counter-current chromatography,” appears in the Journal of Chromatography A, 1216(2009)6162-6169.  Check it out!!

NOT just another flavor separation

Thursday, August 13th, 2009

On a rainy fourth of July weekend, my brother Sam and I were hard at work in the lab working on our latest project. CCC flavor separation.  Admittedly, we were not happy about missing out on bbq, beer and fireworks, but we were both excited about getting this project started. Our ultimate goal? To put the power of flavor separation in the hands of chefs, which is a power that is now largely restricted to flavor houses.

It  started a few weeks earlier. As I was impatiently waiting in outbound Chicago traffic, on my way home for the weekend, I get a call from Sam.  He wanted to talk with me an idea he had about using CCC for flavor separation.  In the kitchen CCC could be used to separate complex flavors into groups of flavor constituents.  A chef with the right CCC instrument and a grasp of the basic concepts could use the technology to either to isolate desired flavors from a mix or remove an undesirable flavor. It sounded great to me. I love food and I’m always game for fun and offbeat projects like this.

Despite many hours logged watching food network, I didn’t know enough about the culinary world to understand how CCC could fit into a kitchen.  I needed to consult and expert. Alton Brown came to mind, but since I didn’t think he’d be particularly easy to get in touch with I decided to call around to talk with some local chefs.  Many calls later with little progress I went to the net to look for culinary folks who were into integrating cool new technology into to kitchen. Enter Dave Arnold.

Food hacker and director of culinary tech at the French Culinary Institute

Food hacker and director of culinary tech at the French Culinary Institute

After talking to Dave Arnold, the director of culinary technology at the French Culinary Institute, I finally felt that I’d found the connection to the inside culinary knowledge that was required for the project.  Dave told me he spends the majority of his day thinking about new ways to tweak flavors. I knew I was talking to the right guy.

After telling Dave about Sam’s CCC flavor separation idea it was time to take this project to the next level.  Sam and I were on a mission to prove that flavor separation on CCC was feasible in a kitchen, which meant we needed a food safe solvent system and proof that it was easy enough to be a practical tool for a chef.

The first step was to design a solvent system that is food safe. It was fairly obvious where we needed to go for food safe supplies… the grocery store! We bought a variety of oils, distilled water and everclear.

A variety of oils and everclear (distilled water not shown)

A variety of oils and everclear (distilled water not shown)

For our solvent system to have any hope of working we needed the system to have a decent settling time. So we spent hours and hours mixing water, alcohol and different oils. Then we shook up all of our prospective systems and timed how long it took for them to separate.

Glass vials fill of prospective food safe solvent systems

Glass vials fill of prospective food safe solvent systems

Our solvent system evaluations lead us to adopt everclear and canola oil for our first attemts at flavor separation.

With our solvent system in place we needed some food samples to try out.

Find what our friends at the French Culinary Institute though of our preliminary flavor separation as the story continues on Dave Arnold’s blog see “Just another flavor separation technique