Interview Janusz Pawliszyn at Pittcon 2011
Sample prep is going live
At Pittcon 2011, we interviewed Prof. Janusz Pawliszyn, who was awarded the Dal Nogare Award in analytical chemistry.
How do you view recent developments in sample preparation?
“Sample preparation technology, as it is currently used in the lab, is very outdated. The reason is because, sample preparation has been designed by industry for industry without much scientific optimisation. Fortunately, new technologies are now being researched and, recently, much better techniques have been introduced. Often, these are now much ‘greener’, resulting in a considerable decrease in the amount of solvents used.
“One of these new techniques is SPME, a technique that I was lucky enough to have invented; it is described in detail in my new book published by Wiley ‘Handbook of Sample Preparation’. Other extraction techniques have also been developed, such as LPME; dispersion techniques include: solid phase dispersion and liquid dispersion. A lot of work has recently been undertaken to improve sample preparation. Supelco introduced SPME commercially, but it is now 20 years old, so there are opportunities for others to work in this technological field. “
What have been the most significant changes in recent years for SPME?
“The main evolution during the last year has been to design biocompatible and general-purpose coatings for in-vivo use and the ‘96 well plate system’. In-vivo SPME focuses on the in-vivo analysis of different tissues of fish and small rodents (blood, brain and liver) for pharmacokinetics and metabolomics. 96 well plate SPME has been developed to achieve the high-throughput of clinical samples for target analysis – as well as metabolomics – particularly for personalized medicinal applications. We hope that in-vivo SPME will be used at one point as an in-vivo probe for medical applications, particularly for people who are critically-injured. These applications would have a great impact on analytical chemistry.
“In the development of sample prep, and especially SPME, there has been focus on new coatings and parameters such as selectivity and sensitivity; more recently, some work has been carried out on matrices (including in my lab). These are summarized in publications such as Chemical Reviews and Angewandte Chemie. Now, you can directly extract from materials like food, soil, and even living systems. Such a product was recently introduced by Supelco for the in-vivo sampling of tissue, liver and other in-vivo material. Advantages of in-vivo techniques are numerous: for example, less-stable compounds can be picked up, without deterioration by enzymes; it also eliminates salt, which is important for LC-MS, and microdialysis techniques.
“In-vivo sampling is a very versatile technique, but we should see it as a toolbox, not a panacea: to be used mostly by biologists in the life sciences. It has great potential. Other methods with a more lengthy approach, or those which use more phase changes, will take the sample away from the system. This will mean that a sample will change and you will then have a problem with less stable compounds such as metabolites. But here you can equilibrate without taking it away from the matrix, so you not only produce less stress in the system, but also you have a truer representation.”
We provide a link here to download one of the review articles on in vivo sampling by Prof Pawliszyn, published in the Chemical Reviews (ACS):
Nondestructive Sampling of Living Systems Using in Vivo Solid-Phase Microextraction.
(Gangfeng Ouyang, Dajana Vuckovic, and Janusz Pawliszyn)