SubscribeMany Pharmaceutical companies use fast LC/MS (Liquid Chromatography/Mass Spectrometer), which can mean analysis run times as low as two minutes, to analyse their samples for pharmacokinetic and drug metabolism studies.
As a consequence of this, sample preparation becomes the rate limiting step. In recent years to try and address this problem the SPE (Solid Phase Extraction) phases of choice have been incorporated into 96 well plate well formats to increase sample processing and throughput.
However some laboratories view that as still somewhat too "slow", therefore to further enhance the speed of sample processing simple protein precipitation procedures were introduced. This basically involves mixing a serum sample with acetonitrile and pipetting this through a filter again, usually in the 96 well plate format. Whilst this approach is very effective and fast it can also mean that unwanted matrix elements can get through to the mass spectrometer source and cause down time whilst cleaning and reassembly procedures are carried out. This can obviously negate any gains made by increasing the sample throughput by using such procedures.
A possible answer to this from several vendors of SPE was to then introduce polymeric "catch it all" phases. These polymers, which were usually based on Styrene Divinyl Benzene (SDVB) were and are still good in the sense that they are very hydrophobic and will therefore retain most parent compounds and water soluble metabolites, which means that the simplest of SPE procedures can still be implemented. However for certain classes of compounds and their extraction of bio fluids these "generic" phases were not specific enough and still co-extracted at the elution step many of the unwanted matrix elements.
The continuing evolution of styrene phases then saw a functionalised versions of these sorbents, in particular with a sulphonated group thus producing a phase with Strong Cation Exchange Function which historically have been very effective at extracting basic compounds. And, given that many new chemical entities in pharmaceutical R&D tend to be basic in function, that is a very useful development indeed.
Leaving aside the issue of having to analyse high numbers of samples very quickly, this course also looks at samples such as tissue and solutions for the extraction of parent compounds and metabolites using Matrix Solid Phase Dispersion (MSPD).
Taking all this into account the ChromSolutions training course aims to re introduce choices and options available in terms of SPE phases, silica based or polymeric, to the end user. Thus we hope to stimulate thinking about just what would be a rugged method and how it might impact the analytical method and instruments of choice. As an addendum to this the course looks at how SPE can be automated and linked directly to the chromatographic method of choice.
These courses are also extremely useful for those laboratory based staff that might want a refresher or update on these techniques. Training Courses For Synthesis and Flow Organic Synthesis Chemistry
This course deals with the clean up and concentration of synthesis reaction mixtures. Many reaction mixtures tend to end up in what are normal phase systems. This then opens up possibilities to use straight forward silica columns to affect a sample clean up. Such Solvent systems also open up the possibility to use very simple procedures using Hydromatrix or kiesel guhr.
The clean up of such samples and the phases used could arguably be the way that opened up more widely the application of flash chromatography and the modern day instrumentation produced to meet the demands of high sample throughput.
Pressure in this area for high sample throughput has somewhat diminished in recent years due to less reliance in many laboratories on combinatorial techniques in favour of more focused arrays. In either case SPE has a pivotal part to play in the clean up of the samples generated. With regard to flash chromatography the course looks at how methods can be developed and optimised and how Thin layer Chromatography (TLC) can assist with that process.
For many synthesis chemistry applications, what are known as scavenger resins help with the overall process and we look at their inclusion and incorporation into 96 well plates, particularly for "catch and release" procedures. The ChromSolutions course also incorporates the use of metal scavenging resins and carbon phases to clean up bulk pharmaceutical processes. Allied to this we also introduce new information concerning the application of flow organic synthesis procedures.
For more information on ChromSolutions SPE Training Courses from Analytik Ltd please contact Kevin Fernandes:
Analytik Ltd
Unit 4 The Acorn Centre
Chestnut Avenue
Biggleswade
Beds SG18 0RA
Tel: +44 (0)870 991 4044
Fax: +44 (0)870 135 2488
Email: kevin.fernandes@analytik.co.uk
Web: www.analytik.co.uk