New Developments in Instrumentation

Most, if not all, companies constantly strive to improve their existing products and develop new ones. This certainly applies to companies in the food industry, but it also applies to manufacturers of instruments for the analysis of foods and beverages. Here is a sampling of some of the instruments introduced within the past year or so by three major analytical instrument companies.

Waters Corp.
Based in Milford, Mass., Waters Corp. (www.waters.com) is said to deliver practical and sustainable innovation to enable significant advancements in such areas as healthcare delivery, environmental management, food safety, and water quality worldwide. Antonietta Gledhill, Business Development Manager, Food and Environment Business Operations, said that the company has a broad range of system solutions aimed at the food and beverage industry. Among the more recent introductions are the Acquity UPLC^® H-Class ultra-performance liquid chromatograph (UPLC) and the Xevo^® G2 QTof time-of-flight mass spectrometer (TOF-MS). Both systems were introduced to the marketplace in late 2010 and have been used by food laboratories all over the world in both quality control and food research applications.

The Acquity UPLC H-Class was developed specifically with quality control departments in mind, she said. It offers high chromatographic resolution, which is an essential requirement when dealing with complex food matrices. It enables chemists to run existing lab methods, delivering the best-achievable high-performance liquid chromatography (HPLC) separations and providing the capability to run more efficient and streamlined UPLC methods within the laboratory. For day-to-day operations, she added, it reduces sample analysis time and cost related to solvent use and fits the long-term business strategies of customers who are implementing sustainability policies to ensure that their laboratories run green operations.

The instrument maximizes chromatographic resolution, permitting the consolidation of multiple analytes into single analytical methods; this wasn’t previously possible due to lack of resolution power, she said. Reducing stationary-phase particle size has long been exploited to improve chromatographic separation efficiency, but until recently liquid chromatography had reached a plateau in which the benefits of reducing particle size could not be fully realized because of instrument band spreading and limited pressure range. The Acquity system overcomes these barriers by using chromatographic columns packed with smaller particles, below 2 microns in size, and precisely delivering the mobile phase at higher pressures, up to 15,000 psi. The instrument is considered a replacement for existing HPLC systems for food QC analyses. One of its key benefits is speed—the time to perform an analytical method using HPLC can be dramatically reduced by 80%–90%.

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The Xevo G2 QTof is capable of obtaining the highest level of chemical information from food samples for both food safety and compositional profiling, Gledhill said. It can maintain excellent mass accuracy of compounds found at very low concentrations in the presence of very high concentrations of ubiquitous compounds. This is especially important when making trace analyses in extremely complex food matrices, she said.

The technology is relatively new to the industry but was brought to the attention of food testing laboratories after high-profile food safety scares because of its ability to perform non-targeted analysis. The instrument provides a way to screen food products for any unwanted chemical contaminants. The company has also been working with the fruit juice industry to use the Acquity UPLC H-Class and the Xevo G2 QTof with MarkerLynx software to determine fruit juice adulteration.

The challenges that the industry faces today, with trying to predict the next food safety scare and ensure consumer safety, she said, are likely to be present for many years to come, but more tools are now available to address the issues when they arise. Sample preparation used to be a huge bottleneck, she said, but as instruments become more sensitive and as chemists seek to learn more about their products, the trend is to move away from sample prep whenever possible although there will still be methods for which it is an essential part of the analysis.

The issue of melamine highlighted to the food industry how a food quality issue can rapidly become a very major food safety issue, Gledhill said. This arose because the commonly used test for protein, the Kjeldahl method, measures nitrogen and not protein and can therefore be cheated by exogenous non-protein nitrogen. This has raised questions about the true efficacy of many of the aged reference methods in use in routine food QC testing today and is creating an interest in adoption of newer, more effective methods such as UPLC and even mass spectrometric methods for food QA/QC analysis. The challenge for instrument manufacturers, she said, is to develop instruments that not only have a small footprint—necessary in the QC environment, where real estate is precious—but also are robust enough and easy enough to be used by less-experienced operators in a busy routine environment. The company, she said, continues to invest significant resources in development of analytical solutions specifically aimed at these markets.

Thermo Fisher Scientific Inc.
Headquartered in Waltham, Mass., Thermo Fisher Scientific Inc. (www.thermofisher.com) calls itself the world leader in serving science, offering products and services that help accelerate the pace of scientific discovery and solve analytical challenges ranging from complex research to routine testing and field applications. Markus Kellmann, Product Manager FT-MS New Technologies, Life Science Mass Spectrometry, said that the company’s newest instrument for analysis of foods and beverages is the Q Exactive high-resolution accurate-mass (HRAM) spectrometer, introduced in June 2011.

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The heart of the benchtop system, he said, is the Orbitrap^TM mass analyzer, which records the ion motion frequency along the center electrode, resulting in a transient signal. By applying fast Fourier transformation on the transient signal, a mass spectrum is generated. The resulting mass spectra are characterized by unmatched resolving power (more than 140,000 FWHM, full width half maximum) and very high mass accuracy (less than 1 ppm). A high-performance quadrupole serves as a mass filter, which allows preselection of ions and reduction of chemical noise, thus allowing quantitation at a level similar to high-end triple-quadrupole instruments, Kellmann said. This, together with the ability to produce HRAM MS/MS fragment ion spectra, enables extremely high levels of confirmation, minimizing false negative results. The instrument works with all atmospheric ionization techniques, he said.

Screening and quantitation in the food safety area have traditionally been performed by triple-quadrupole mass spectrometers because of their high sensitivity, high speed of analysis, and specificity, Kellmann said, but the focus has always been on targeted analytes. Within this methodology, a limited set of analytes have to be defined before analyses are conducted, all compounds have to be optimized separately, and the confidence of confirmation by low-resolution fragment ions is still the cause of divergent discussions. In contrast to this targeted approach, there is more interest lately in non-targeted approaches.

Using intact compound molecular ions for quantification and complete fragment spectra for high-confidence confirmation of known compounds or even identification of unknowns, HRAM analysis over a wide mass range by means of the Q Exactive will overcome these limitations, Kellmann said. Because of the constantly growing number of regulated substances, a clear trend toward multi-residue methods in combination with comprehensive sample preparation approaches like QuEChERS is emerging. The Q Exactive is capable of resolving virtually all matrix interferences from the compounds of interest, providing low-noise-extracted mass chromatograms even for the most complex crude extracts. In addition, it allows the identification and quantitation of complete unknowns using HRAM. After data acquisition in positive and/or negative ionization modes by liquid chromatography-mass spectrometry (LCMS), the files can be interrogated retrospectively multiple times for virtually any compound.

One challenge in the development of new instruments for food and beverage analysis, Kellmann said, is to provide easy-to-use instruments for routine multi-residue, multi-class analysis for both targeted and unknown screening and quantitation at the current performance level for every food testing laboratory and therefore also for every budget. The company is constantly working on improvements in scan speed, ultra-high-performance liquid chromatography (UHPLC) resolution and sensitivity to support the increasing requirements in food safety analysis.

Another challenge, he said, is analyzing the expansive amount of information collected in each HRAM data file. The company is working on software solutions to automate much of this work and provide quick answers for the analyst. The forthcoming ExactFinder™ software for the instrument will combine new and well-known software tools into one suite and substantially improve data processing for screening, quantification, and unknown analysis. The company, he added, will continue with these endeavors for future-generation products and solutions that will allow the food supply chain to be safer.

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Another recent development from the company is its recently introduced ToxInsight IVT (in vitro toxicology) platform. Martin L. Pietila, Global Manager of New Markets, Life Science Research-Cellomics, said that environmental toxins called endocrine active chemicals (EACs) act like the natural sex hormones estrogen and androgen and interfere with the reproductive system of both humans and animals. To date, screening for EACs has required mass spectrometry to identify toxins with known spectrometric signatures. The ToxInsight IVT hardware and software and associated Endocrine Profiler Panel assays enable highly sensitive detection of EACs from complex mixtures and provide an in vitro non-targeted screening platform for identifying the presence or absence of EACs in the environment, food packaging, food ingredients, pharmaceuticals, plastics and resins, and consumer chemicals.

The basis for the detection is an engineered human cell line expressing the estrogen or androgen receptor fused to a green fluorescent protein. Upon activation by a suspected EAC, the receptor translocates to the nucleus of the cell, and the fluorescence imaging system directly visualizes the activated receptor and reports the magnitude and potency of the response using sophisticated image analysis algorithms, compared to known endocrine disrupters such as BPA and dihydrotestosterone. The platform provides significant savings in time and cost over older test methods that rely on animal extracts and a wide range of chemicals, instrumentation, and software tools, Pietila said.

PerkinElmer Inc.
Based in Waltham, Mass., PerkinElmer Inc. (www.perkinelmer.com) bills itself as a global leader focused on improving the health and safety of people and the environment. Ravindra Ramadhar, Director of Food & Consumer Goods Safety, said that the company introduced a number of new instruments in 2011 that incorporate industry-leading detection levels, ease of use, lower maintenance requirements, and user-friendly software. The Spectrum Two^® infrared spectrometer and the AxION™ 2 TOF-MS platform are instruments that he said will revolutionize the use of analytical instrumentation and help guarantee the safety and quality of foods.

Spectrum Two, introduced in February 2011, is designed for everyday quality and safety analysis, such as detection of contamination, economically motivated adulteration, or counterfeiting applications. It provides fast, accurate infrared analysis in a compact, transportable design, suitable for use in the laboratory or the field. While the underlying instrumentation technology is complex, the instrument automates the interpretation of IR spectroscopic results and is easy to use. A user-friendly touch-screen interface allows results to be obtained faster than ever before.

The instrument uses a fixed-mirror-pair interferometer design that does not require dynamic alignment to compensate for errors found in linear-mirror-movement systems, Ramadhar said. It is portable and includes a wireless interface, minimizing the possibility the system will be damaged in a harsh environment and making it ideal for use from the loading dock to the lab. Since raw material testing is typically done in an area with little climate control, he said, the effects of temperature and humidity must be considered to allow consistent results. With this in mind, the instrument was designed with a humidity shield to protect it from environmental effects, allowing it to be used in more challenging environments.

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The AxION 2 platform, introduced in June 2011, features five orders of linear dynamic range for quantification, high specificity so no extensive chromatographic separation is required, high scanning speed, exact mass capabilities for confident confirmation of compound identity, and isotope-ratio confirmation for further confidence in routine quantitative pesticide analysis, targeted screening of pesticides and other chemicals, and detection and identification of unexpected compounds. The platform includes hardware and software specifically designed to deliver rapid and accurate mass identification and quantification.

The hardware consists of the AxION 2 TOF-MS instrument and a choice of ion sources that are said to deliver the most efficient nebulization, fastest desolvation, and most effective ionization of any TOF system, Ramadhar said. The Ultraspray™ 2 adjustable dual-probe electrospray ionization source allows users to optimize the angle of probes to achieve the best sensitivity. The design also lets users dedicate one inlet to a sample and the other to an internal standard. By doing so, one can avoid contamination in the sample probe and achieve the highest mass accuracy—without affecting sensitivity or resolution—by performing real-time calibrations. The other available ion source is a field-free atmospheric pressure chemical ionization source that maximizes ionization efficiency and sensitivity at very low flow rates, he said, allowing users to achieve optimum results while using less sample and solvent. Each source has interchangeable snap-in probes to enhance productivity and user flexibility by reducing cross-contamination. The platform also includes a variety of software packages for analysis and reporting of results.

Food and beverage customers present a unique challenge to instrument developers, Ramadhar said. On one hand, they need powerful and complex instrumentation and techniques for the required actionable results. But on the other hand, they require instruments that are easy to use and generate clear results. Instrument development must address both these needs, he said. Globalization, changing technical levels, and training of staff are driving instrument robustness and greater automation of results. To better serve the needs of the food industry, he added, companies must ensure that instruments are designed for the rigors of a food production environment and manage the complex matrices associated with food. Instruments must be designed to operate in harsh and non-laboratory environments and require less maintenance and calibration.

PerkinElmer is always looking into the future to add software functionality and analytical capability that customers demand, Ramadhar said. Ease of use, field deployability, and ability to move the instrument to various locations are always on the development screen. Increased productivity, more-efficient reporting, and integration with other informatics needs in the laboratory are high priorities that the company will continue to develop over the next few years, he said.

 

Neil H. Mermelstein, a Fellow of IFT, is Editor Emeritus of Food Technology
[email protected]