Technology Forum: GC

While gas chromatography has long been considered a “mature” technology, its prominence and continued utility in areas such as food safety, petroleum research, and environmental testing remains unchallenged.

This month, Chromatography Online's Technology Forum looks at the topic of GC and the trends and issues surrounding it. Joining us for this discussion is Trisa Robarge of Thermo Fisher Scientific, Kaj Petersen of GERSTEL, and Sky Countryman of Phenomenex.

What trends do you see emerging in GC?

Robarge: Gas chromatography is seen as a mature technique, and this might lead some to believe that it is therefore not continuing to evolve. However, advances and innovations in gas chromatography continue to emerge every year as technology increases. We can envision GC systems that are smaller, faster, and easier to use, with detectors designed to meld with fast and ultra-fast chromatography. We also see that modern sample preparation techniques will be increasingly included in the GC instrument package. In addition, trends toward detectors that offer more specificity and selectivity, such as mass spectrometers, means that laboratories will be moving away from the traditional GC detectors, increasingly incorporating MS for detection.

Petersen:It’s all about throughput and reliability. Labs are looking to run more samples with less operator involvement, 24/7. Automated sample introduction has to be reliable, sample preparation preferably included. Laboratory GCs will offer incremental increases in speed of analysis, based on standard GC instruments. Additionally, oven cool-down speed is constantly being improved to shorten run-times and increase throughput. Established analyses have been, or are being, ported to moderately narrow bore columns such as 0.25 mm ID. Here the optimum is currently found between analysis speed and sufficient capacity to handle real life samples in a rugged and reliable manner. Narrower columns enable shorter run times coupled with excellent separation while also reducing carrier gas consumption, an emerging factor given the rising prices of and depleting resources of Helium. More labs will switch to hydrogen carrier gas for faster GC separation and significant cost savings, accelerating the need for adequate safeguards. Fast, automated sample preparation techniques are emerging to match shorter GC run times. Autosamplers will increasingly be able to automate tasks such as analyte concentration, derivatization, and the addition of internal standards. The next sample will just have been prepared and will be ready for injection when the GC becomes ready after analyzing the current sample. It’s all about maximizing sample throughput.

Countryman: Currently there are several trends emerging in GC. One of the biggest trends is the need for turnkey solutions – systems that will provide GC chemists with a complete solution that includes everything needed for their work. Turnkey solutions help to streamline a laboratory by eliminating a lot of guesswork, trouble shooting, and method development typically needed.

In addition, there is a trend towards higher sensitivity and faster analysis. These factors are critical for big industries, such as the environmental industry. In recent years, as the focus on environmental contaminants and clean-up has grown, there is increased demand for more sensitive analytical tests to measure the amount of pollutants in the environment as well as in humans. Chemist will always be seeking to detect lower amount of pollutants than is currently possible.

What is the future of GC?

Robarge: Gas chromatography will continue to be relevant in the analytical labs of the future. It is easy, inexpensive, fast, and provides a complementary analytical technique to liquid chromatography. This complementary relationship between GC and LC separations provides laboratories with a powerful set of tools to address their application concerns. Integration of these two complementary techniques will be better explored in the future, not only as separate instruments performing separate analyses, but also as a unique hyphenated offering that takes advantage of the unique potential of each separation type in the characterization and analysis of difficult matrices.

Continued innovation in GC column design and manufacturing is also needed to ensure that analytical phases offer the required durability and separation power for GC applications. Inert, low-bleed phases are essential for meeting required detection limits, yet these columns must also be able to provide a high level of performance over a large number of samples to ensure lowest cost per sample.

Finally, we see a tendency to use GC as a rapid monitoring technique for the control of contamination, adulteration, industrial processes, or as a preliminary screening for a large amount of samples to be analyzed. Compact and powerful GCs therefore can play a role in a variety of routine analytical tasks wherein they become analyzers instead of instruments, moving beyond application areas where GCs already play a similar role. Software development must follow hand-in-hand with hardware development to ensure ease of use not only in terms of using the instrument itself, but in using the entire system.

Petersen:The future for GC is bright! More samples will need to be analyzed and more compounds determined at ever-lower levels to ensure safe, high quality products, and safe product packaging for foods, drugs, and consumer products. The environment will still be there to be monitored.

Countryman:Since GC is an established technique, the future is not so much in new applications areas but in developing turnkey solutions. Analysts are looking for solutions that are simple and easy to implement.

What is the GC application that you see growing the fastest?

Robarge: Petrochemical, palm oil, and biodiesel applications are going to be key focal points for gas chromatography, particularly as the prices of natural gas and petroleum continue to rise and supplies shrink. GCs will also play an integral role in the burgeoning food safety and food analysis markets, primarily coupled with mass spectrometry but also with traditional GC detectors for rapid screening of food supplies. For example, gas chromatography coupled with a triple quadrupole mass spectrometer can provide fast and definitive identification of pesticide residues in food within minutes. To reduce costs and shorten analytical times, the systems must be robust and capable of handling the heavy matrix components typical of food samples. In this respect, integration of sample preparation, specifically tailored for the different food matrix, will be a key development in the future. GC systems for food analysis must offer low detection limits, high sample throughput, reliable performance with dirty samples, and analysis and reporting packages that allow laboratories to review and report data quickly, easily, and in formats that meet regulatory requirements.

Petersen:This is a very difficult question and there may be no clear answer. GC is firmly established in a large number of applications and markets. There is some limited activity in biotechnology, but this is not very significant compared with the overall market.

Countryman:GC testing will also increase for the biofuels industry. Alternative fuel is relatively new and rapidly growing in many parts of the world. As the market becomes more established, there will be stricter fuel quality requirements as well as new mandates to measure the environmental impact of a biofuel plant.

In addition, food safety testing will continue to grow. The latest melamine crisis has caused consumers, as well as manufactures, to be more cautious of components in food products. As a result, GC food testing will increase as a precautionary measure for ensuring the public’s health.

What obstacles stand in the way of GC development?

Robarge: One of the key obstacles to GC development may be the underlying feeling that this mature technique could no longer benefit in terms of continuing innovation and development. The high visibility and adoption rate of liquid chromatography also overshadows some of the advantages of gas chromatography, making this market's relatively slower growth rate seem less attractive in terms of development. The market also seems to underestimate or overlook the potential of emerging multidimensional GC techniques that can greatly expand the separation power and selectivity of gas chromatography. However, as laboratories look to replace aging instrumentation or expand their test offerings, they will look to the GCs of today and tomorrow to offer better performance, reliability, and ease of use than the GCs of the past, and manufacturers need to continually innovate to ensure that new GCs meet these expectations.

Petersen:For laboratory GCs, the immense multitude of applications means that no standard “Cartridge” GC will meet all requirements except, maybe, for dedicated process analyzers. The standard GC oven that can be fitted with a wide variety of standard GC columns will be with us for a long time yet. So far, no products that apply other types of heating of the GC column have been able to offer the same flexibility or the same level of ruggedness.

Countryman:The biggest challenge in GC today is actually sample preparation. A large part of an analyst's time is spent cleaning and preparing samples. Thus, many methods are being moved to LC-MS-MS because the analytes are more stable and require less sample preparation before analysis.

Do you expect any major GC developments/news to be presented at Pittcon 2009?

Petersen: I would be surprised to see a major break-through in GC itself, but there will be significant improvements that help GC-users become more productive, especially in the field of automated sample preparation.

Countryman:It's most likely that companies will continue to focus on application-specific solutions. Application-specific solutions will continue to be very important to GC chemists.