New Products for Gas Chromatography at Pittcon® 2014

Pittcon® is changing rapidly. After decades where separation science including GC/MS and LC/MS dominated the meeting, a report by Dr. Matt Wilkinson demonstrates that optical spectroscopy has stolen the limelight. With improved batteries and novel solid-state optical devices, many booths exhibited handheld spectrometers, particularly Raman and laser induced breakdown spectroscopy (LIBS). Brian Musselman has prepared a similar review of mass spectrometry.

Scientists interested in HPLC and related techniques should see a report on HPLC 2013 in Hobart, Tasmania, Australia. New items at Pittcon will be reviewed in an upcoming issue, along with those revealed at HPLC 2014, scheduled for May 10-15 in New Orleans, LA. Although HPLC is the largest technology segment in the laboratory marketplace, three articles in four months seems excessive.

GC instruments

Pittcon is no longer the dominant trade show in separation science. There are other choices, such as Analytica, BECIA, and HPLC, and for GC, Capillary Chromatography.

No firm chose Pittcon for introduction of a new platform gas chromatograph. I did not find any new columns either. What caused the drought? Several potential factors come to mind: 1) The GC development cycle is probably about five years from inception to rollout; 2009 was a tough year economically. GC redesign was probably put on hold until the economy improves. 2) There is little market demand for “smaller, faster, better” GCs. Micro GCs exist, but I’ve never heard anyone claim that they have been commercially successful. Plus, benchtop GCs are among the most reliable instruments in the lab space. The oven fan is the only moving mechanical part. However, several firms introduced application-specific analyzers.

Application-specific analyzers

GC with model 5380 pulsed flame photometric detector

O.I. Analytical (College Station, TX; www.oico.com) exhibited a GC equipped with the model 5380 pulsed flame photometric detector optimized for assay of low levels of sulfur analytes in spearmint oil. Spearmint oil is an important item of commerce, with 1 million kg/yr produced for flavoring chewing gum and toothpaste. Each 55-gal drum is sufficient for 5,200,000 sticks of gum.

TOGA-005 GC, dual-column system, and FTA-057 Cannabis THC Potency Analyzer

Since Pittcon 2013, GenTech Scientific (Arcade, NY; www.gentechscientific.com) has introduced three application-specific analytical systems utilizing GC. The TOGA-005 GC is optimized for analysis of transformer oil gas. It is equipped with a thermal conductivity (TC) and flame ionization detector (FID). A catalytic methanizer converts CO and CO2 to methane, enhancing detection with the FID. A headspace sampler passes the methane to the split/splitless injector. Protocols meet the requirements of ASTM D-3612C.

Blood alcohol by headspace GC is commonly used in forensic labs. GenTech’s dual-column system assays for ethanol on one column and related volatile analytes on the second. Both columns feed separate flame ionization detectors.

The FTA-057 Cannabis THC Potency Analyzer applies GC technology to determination of tetrahydrocannabinol in various sources. THC’s psychoactive effect requires about 10 μg/kg of body weight. Other related cannabinoids may also be psychoactive. Since the illicit market is known to deliver adulterated products, consumers demand potency information. If you are interested in more, visit www.gentechscientific.com/news/make-sure-it-s-the-good-stuff-cannabis-thc-potency-analyzer.

Natural gas, natural gas liquids, crude assay, detailed hydrocarbon, and refinery gas analyzers

The shale gas and oil boom comes from a mixture of deposits, each with a different product profile. The Marcellus Shale in New York and Pennsylvania produces primarily natural gas with lots of water; the Eagle Ford in Texas yields light sweet crude, with almost no water, etc. Alpha Omega Technologies, Inc. (Brielle, NJ; www.aoti.net) introduced four GC-based analyzers including a natural gas analyzer, natural gas liquids (LGN) analyzer, crude assay analyzer, and detailed hydrocarbon analyzer (DHA). All are designed to comply with the requirements of ASTM and other metrology agencies. Generally the analyzers are built around an Agilent 7890 GC (Agilent Technologies, Santa Clara, CA; www.agilent.com).

Alpha Omega also makes analyzers for petroleum processing. The high-speed RGA (refinery gas analyzer) is optimized to assay C1 through C6 hydrocarbons, H2, CO, O2, and N2 in 100 sec. The 7890 is fitted with a split/splitless inlet. Detection is with an FID and two TC detectors. Stainless steel is passivated with SilcoNert™ 2000 (Silco Tek, Bellefonte, PA; www.silcotek.com). Since there is more room for maintenance and repair, users often favor the 7890 GC over micro GCs.

Reducing Compound Detector

Peak Laboratories (www.peaklaboratories.com), nestled in Mountain View, CA, in the heart of the Silicon Valley is another firm with a very tight applications focus. Peak’s is on chromatography-based process analytics for the semiconductor industry. This industry segment uses large quantities of very pure gases to produce modern electronic components. Most products are optimized for the particular application. Peak generally uses flame ionization and thermal conductivity detectors. However, I was impressed with the Reducing Compound Detector, which is specific for detection of hydrogen, carbon monoxide, and select hydrocarbons in high-purity gases including N2, He, and Ar. When reducing compounds interact with the mercuric oxide, metallic mercury, which is volatile, is generated. Mercury vapor is detected with UV absorbance. Detection limits are generally in the high-ppt range.

GC detectors

Master TOF Plus MS detector for GC/MS

Displaying its customary touch of class, DANI Instruments S.p.A. (Milan, Italy; www.danispa.it) introduced the Master TOF (time of flight) Plus MS detector for GC/MS. The detector acquires up to 30,000 spectra/sec. Usually these are combined and averaged to provide a reported output of 1000 spectra/sec saved to disk. This compression provides noise reduction even for the narrowest peaks, which are usually tens of milliseconds. Noise reduction also improves dynamic range, which is 105. The Master TOF is remarkably small with a 22 × 53 cm footprint × 41 cm tall.

The novel ion optics pulses the ions into the short flight tube. This provides detection sensitivity similar to the best of quadrupole mass analyzers operating in single-ion monitoring mode. Yet since you see all the spectra, you see unanticipated peaks.

In addition to the GC-TOF MS Plus, Dani offers autosamplers and software for operation and chromatogram evaluation. The latter is aided by rapid peak deconvolution subroutines.

Update on Catalytic Combustion Ionization Detector

In the booth of DETector Engineering and Technology, Inc. (Walnut Creek, CA; www.det-gc.com) Dr. Paul Patteson discussed improved performance of the unique Catalytic Combustion Ionization Detector (CCID), which selectively responds to n-paraffins, particularly in fuels. The key is the partial pressure of oxygen. At higher pO2, the detector responds to other isomers. At still higher oxygen content, the thermionic surface of the TID-10 will also respond selectively to oxygenates in fuels. These detectors fit on Agilent 6890 and 7890 (Agilent Technologies) and Thermo 1300 GCs (Thermo Fisher Scientific, Waltham, MA; www.thermofisher.com).

New autosampler for GC

EST Analytical (Fairfield, OH; www.estanalytical.com) introduced the FLEX rail format autosampler for gas chromatographs. This autosampler is capable of both sample preparation and sample introduction. For sample introduction it is compatible and can be mounted to any GC manufacturer’s system. The autosampler is capable of liquid injection in single or multi injectors. Options include: SPME Fiber conditioner with Tmax of 350 °C, headspace option that holds heated syringes up to 2.5 mL, and Water Rinse/Waste Station. The Incubate/Agitate box is capable of heating to 200 °C while agitating vials. Rack capacity is four racks each holding 105 vials (2.5 mL) or 32 headspace vials. In addition, the FLEX offers a simple and intuitive user interface that provides a unique drag and drop method developer, simplistic rail configuration setup, and easy instrument calibration. Wireless communication facilitates movement of the autosampler around the lab without the rewiring required for earlier generation autosamplers. The FLEX autosampler is made in the U.S.A.

Modules for Multipurpose GC Sampler

Gerstel (Mülheim an der Ruhr, Germany; www.gerstel.com) has focused on sample processing. The company has carved out an interesting niche in sample processing at the front end and supported applications overall. Gerstel uses Agilent’s chromatographs for the analytics. This meets the needs of the customers for supported assays rather than chromatographs.

Cases in point: Gerstel continues to flesh out the Multipurpose Sampler Platform (MPS) by adding a vortex/shaker option. It is capable of 3000-rpm vortexes in vials. It also works with samples in multiple-well plates.

The Pyro module can program heating of samples to a maximum of 1000 ºC for evolved gases, pulsed pyrolysis, fractionated pyrolysis, etc. The Thermal Desorption Unit (TDU) can be mounted on the MPS with the Pyro unit to desorb volatiles prior to pyrolysis. If you need rapid heating, there is a microwave-powered solvent extraction station. This is suitable for assay of fatty acid methyl esters of fats in foods.

Also for the MPS, Gerstel added an automated filtration accessory that uses Luer fittings. Sample filtration often improves method robustness. The mVAP is a six-position evaporation station that also fits on the MPS.

Generally it is used for solvent exchange to improve chromatography or detection.

Although Gerstel’s prior autosampler had a large capacity, advances in GC analysis speed dictated the need for a higher-capacity design. Plus there was a desire to have tools available to support injection by liquid, headspace, and SPME. All MPS units are controlled via Gerstel’s MAESTRO software.

Portable gas sampling units

Gas sampling in the field is now much less cumbersome with two new products for gas sampling from Gerstel. All collect samples by drawing air through sorbent tubes. The smallest is the GSS-HH for handheld with a weight of only 2.5 lb. Three flow rate ranges are selected covering 5-500 mL/min. The NiMH battery is sufficient for 12 hr. Data for each tube are collected in the HH for loading into a host computer or LIMS. Capacity is two tubes.

For more intense sampling, Gerstel developed the GSS-FP for field portability. It weighs 20 lb, including a lead-acid battery, and contains 28 sorbent tubes fed by two independent flow paths.

GC valves

In GC, valving is essential to upgrade a gas chromatograph to an analyzer such as a refinery gas analyzer. Such valves must be small and reliable for starters. Plus, some will operate at elevated temperature. Norgren (Thetford Mines, Quebec, Canada; www.norgren.com) is a vendor of valves and manifolds used in process instrumentation and control.

Recently the company started promoting valves for gas chromatography and liquid chromatography under the AFP brand. Norgren’s rotary sample injection valves provide low torque actuation. But when the valve is stationary in one of the correct positions, the valve is designed to increase the pressure holding the rotor and stator together, which reduces leaks. Some valves provide a purge port that reduces contamination. Norgren also manufactures syringe pumps that can be used to meter chemicals or samples for prerun processing. The firm is experienced in manufacturing valves from PEEK, PTFE, polyamide, and many metals and alloys.

Summary and outlook

Several major vendors in the laboratory space in general and separation science in particular were absent again, while others downsized their footprint on the floor. However, the space was eagerly taken over by many small startups in optical spectroscopy and a few larger firms from Asia. A decade ago, it was clear to me that as soon as production in China exceeded domestic demand, exporting would increase. This is happening now. It will be interesting to see how these firms find and manage distributors, particularly in the U.S.A., where the number of distributors with national scope is very limited. The other alternative is to establish direct sales and support operation. Only well-funded firms can afford this option.

Robert L. Stevenson, Ph.D., is Editor, American Laboratory/Labcompare; e-mail: rlsteven@yahoo.com.

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