Pittcon Showcases Biosensors and Analytical Instruments

Pittcon 2002, the 53rd Pittsburgh Conference and Exposition, was held in New Orleans, La., on March 17–22. It is probably the largest continuing meeting dealing with scientific instruments and analytical chemistry.

In spite of recent economic conditions, Pittcon 2002 was very successful. Attendance (more than 22,000 registrants) was slightly higher than last year. More than 1,200 companies exhibited the latest in laboratory equipment and instrumentation. The technical program included more than 2,300 technical presentations, 87 short courses, and 115 new product forum presentations. Next year’s conference and exposition will be held in Orlando, Fla., March 10–13, 2003.

This short report on this year’s conference and exposition will cover some of the technical presentations and exhibits of interest to food technologists.

Technical Presentations
Here are brief descriptions of some of the sessions of interest related to food:
History of analytical chemistry was the subject of the opening session presentation. Allen J. Bard of the University of Texas at Austin opened the conference with his plenary lecture, “The Fall and Rise of Analytical Chemistry in the 20th Century—What’s Next?” He discussed the history of analytical chemistry during the past century. The field showed an early rapid advance, he said, followed in the 1960s by a period of stagnation and difficulty in some of the leading academic institutions. This was followed by remarkable advances in almost all fields—electrochemistry, spectroscopy, separations, and mass spectrometry.

Biosensors for food analysis was the topic of a symposium chaired by Antje J. Baeumner of Cornell University. The symposium, “Biosensors and Bioanalytical Microsystems for Food Safety,” looked at the field of bioanalysis of foods for the presence of genetic modifications, toxic chemicals, and pathogenic organisms. New developments in immunoanalysis include the rational design of the antibodies by phage-display, molecular-imprinting, and recombinant techniques. Gene probes and nucleic acid amplification techniques are revolutionizing the detection of pathogenic microorganisms that have been the cause of many recent food poisonings. These improved biological elements are being combined with novel engineering in micro and nanofabrication.

According to speakers at the symposium, microfluidic devices and micro total analysis systems (mTAS) are going to be the bioanalysis systems of the future in food safety analysis.

--- PAGE BREAK ---

Genetically modified foods was the subject of a symposium, “Genetically Modified Foods: Feast or Frankenfoods,” arranged by Richard A. Durst of Cornell University. At the present rate of population growth, it is estimated that there will be 9 billion people on earth by 2050. This population growth will probably require a doubling in food production. While genetically modified (GM) food cannot meet this increased demand by itself—other technological improvements in food production must also be developed—GM foods cannot be rejected if the world’s people are to be fed. However, the world seems increasingly divided into those who favor genetically modified, or engineered, foods and those who fear them.

Genetic modification is the application of recombinant DNA technology to the genetic alteration of microorganisms, plants and animals. Despite the opposition, the trend toward more GM foods seems unstoppable. In 1990, there were no transgenic crops in commercial cultivation, but by 2000 an estimated 100 million acres were used for their production.

Are foods made from genetically modified crops just as safe as those made from conventional crops? Both sides of the argument were presented in this symposium. Opponents argue that such foods are unnatural and therefore bad, that they are dangerous to humans, and that they are a threat to the environment. Proponents counter that all crops are unnatural and have resulted from centuries of breeding, no scientifically valid tests have shown any toxicity to humans, and, while a negative environmental impact is possible, there are few data available to support this contention. Much of this debate hinges on the perception of safety.

The symposium speakers addressed the question of what constitutes a GM organism and discussed the safety and hazards of these organisms. They described how chemists are developing analytical methods to detect genetic modifications.

Detection of prions was the subject of the symposium, “Return of the Mad Cow: Detection and Quantification of Prions—Part II,” arranged by Brian K. Nunnally of Eli Lilly and Co. and Ira S. Krull of Northeastern University. Transmissible spongiform encephalopathy (TSE) has been a hot topic in the mainstream press for the past few years. In 1996, the bovine version of the disease—bovine spongiform encephalopathy (BSE) or “Mad Cow disease”—emerged in humans in the United Kingdom. As of July 20, 2000, it had been credited with 77 deaths. Just within the past 2–3 years, numerous instances of BSE have been reported in most of Western Europe. Additional testing is on-going in other parts of Europe and Asia, but virtually no testing of animals destined for routine human consumption has been undertaken in the United States.

Recently, U.S. Dept. of Agriculture ordered more than 375 sheep in Vermont to be slaughtered because they were infected with the sheep TSE, also known as scrapie. TSEs are 100% fatal, causing dementia and progressive brain deterioration. Many other TSE diseases, such as Kuru (first identified in cannibals), chronic wasting disease (found in elk and deer), and mink spongiform encephalopathy, have been identified. Semi-routine testing is being done in the Western U.S. for wild animals, such as elk, deer, and longhorn sheep, and several cases of TSE have been reported. Testing of dairy or beef cattle herds has never been undertaken on any large scale anywhere in the U.S. It is still unclear today what, if any, is the status of TSE or BSE within U.S. food sources. It is also unclear if these animal diseases can be transmitted to humans by other than direct meat consumption (e.g., milk, blood, cheese, etc.).

The analytical tools used to detect prions, the TSE disease-causing agent, have recently become sophisticated enough to allow for rapid detection and quantification. Most of these methods involve some form of immunoassay, and HPLC and HPCE methods have recently been described in the literature. However, most routine testing for TSE agents until now has involved conventional immunoassay or bioassay methods.

Animals with active symptoms can be diagnosed via autopsy. Infected animals in a dormant disease state are more difficult to diagnose, since they have not yet shown symptoms. The primary accepted detection method consists of slaughtering the animal, removing brain matter, and infecting a host with the brain tissue (e.g., mouse bioassay). A several-week bioassay then determines if the animal is infected or not.

The symposium focused on some of the most recent research in the fields of prion detection, identification, and quantification.

--- PAGE BREAK ---

Rapid methods were the topic of a workshop arranged by Purnendu C. Vasavada, University of Wisconsin–River Falls and Richard Durst, Cornell University. The workshop, “Rapid Methods and Automation in Food Safety and Quality Assurance,” focused on how, in response to consumers’ demand for safe, convenient, nutritious food with a reasonable shelf life and cost, the food industry has adopted proactive and preventative programs such as HACCP, TQM, and ISO.

These programs, as well as increased requirements from vendors and regulators in proving safety, quality, and authenticity of foods and ingredients, has led to developments in a rapid and automated methods for food safety and quality assurance. The workshop addressed recent developments and issues dealing with detection and characterization of pathogens and toxins as well as biosensors and GMO testing.

Instrumentation
Among the many exhibits applicable to food analysis were the following:
Ion Chromatograph for the separation of inorganic anions and cations was introduced by Dionex Corp. The ICS-90 is said to combine an extremely compact unit, high performance, and separations flexibility. The product is intended for customers that have limited budget, but need complex separations and excellent signal-to-noise ratios. The unit is said to offer exceptional baseline stability and compatibility with a range of columns. The unit is controlled by Windows-based software. This control and data acquisition interface has many advanced features, including versatile calibration processes, intuitive instrument control, customizable print functions, searchable database functions, and USB connectivity for simple installations. For more information, contact Dionex Corp., P.O. Box 3603, Sunnyvale, CA 94088-3603 (phone 408-481-4274, fax 408-735-9413).

E-Nose and E-Tongue Instruments exhibited by Alpha M.O.S. have a variety of applications in the food and beverage industries. The E-Nose is a screening tool for aroma and VOC analyses. It allows verification of incoming raw materials and detects taints/off-odors before product shipment. The instrument features chemical sensors, mass spectrometry, and control charting. The E-Tongue is designed for measuring dissolved compounds and taste substances in liquids. It allows product conformity testing, taste default detection, bitterness masking, and substance quantification. For more information, contact Alpha M.O.S. 20 Av Didier Daurat, Toulouse, France 31400 (phone 011-33-5-62475380; www.alpha-mos.com).

Yield Test Rheometer, the YR-1, may be used in food quality control applications. The rheometer is said to be a simple-to-use, low-cost alternative to complicated, full-featured laboratory rheometers. It is designed to be used on the production floor by quality assurance technicians. The user selects a test, lowers the vane spindle into the product, and presses the start button, and the instrument displays the result as a single shear stress number for the material’s yield value. For more information, contact Brookfield Engineering Laboratories, 11 Commerce Blvd., Middleboro, MA 02346 (phone 508-946-6200 or 800-628-8139; fax 508-946-6262).

Measurement of Fat, Fluid, and Lean Tissue in live mice was an application developed for the Bruker minispec NMR analyzer. The method is said to be more precise than the existing DEXA method. The company, in collaboration with Echo Medical Systems, offered the minispec Magnetic Resonance Analyzer for whole body fat and lean tissue analysis in live mice. Although not of direct application to the food industry, the method is of interest to those working in obesity research. The NMR technique penetrates the entire sample volume and can provide three components of interest: fat, fluid, and lean tissue values. The measurements are conducted with non-anesthetized mice in less than 2 min without sample preparation. It produces more precise results than the DEXA method, and the nondestructive nature of the NMR technique maintains the valuable sample for long-term studies. For more information, Bruker Minispec, 12635 N. Crescent Ridge Dr., The Woodlands, TX 77381 (phone 281-292-2447; fax 281-292-2474).

--- PAGE BREAK ---

Rapid Sugar Determination in turbid samples is possible with the OXI 50 UV analyzer. The unit can oxidize different kinds of glucose into aldehydes, which can be detected through UV spectrophotometric reading. The company claims that its innovative technique can be used with turbid samples and is not sensitive to chemical interferences. The photooxidation module and UV analyzer are used as a unit for sugar titration control in soft drinks, wine, fresh juices, and other beverages. For more information, contact Secomam, 1/3, rue des Charbonniers, 95335 Domont Cedex, France (phone 011-330-139-35-4200).

pH Electrodes were on display on at the Mettler Toledo booth. The InLab® 425 pH electrode measures 0.75 in and features built-in temperature probe, bridge electrolyte chamber, and a movable sleeve junction. The built-in temperature probe allows calibration at room temperature and measurement at the temperature specific to the sample. The company claims that the user can test dairy products, oily samples, nonaqueous samples, or highly viscous solutions with the same results. The refillable bridge electrolyte chamber ensures that the bridge electrolyte will not react with the sample. To combat blocked diaphragms, the electrode features a movable sleeve junction. The junction can be cleaned by simply sliding up the sleeve. This is particularly useful when measuring pH in highly viscous samples and emulsions, as well as nonaqueous samples.

The InLab 432 and 433 electrodes are offered with three ceramic junctions. The triple junction ensures higher electrolyte flow and therefore fast response. The special 170-mm length, a built-in temperature probe, as well as the triple junction, is said to make the 432 model suitable for general aqueous samples. The membrane glass used for both models is high-alkali (HA) glass, which shows good linearity over the full pH range and reduces the alkali errors to a minimum. pH measurements of low ionic strength solutions can be done very accurately using 1 mol/L KCl as the bridge electrolyte. For more information, contact Mettler-Toledo Inc., 1900 Polaris Pkwy., Columbus, OH 43240 (phone 800-638-8537; www.mt.com/na).

HPLC Columns that are said to exhibit superior retention of polar compounds and can operate in 100% aqueous mobile phases were offered by Waters Corp. The Polarity™ reversed-phase C18 columns are suitable for compound discovery, development, isolation, and purification. The columns are mass spectrometry-compatible and available in a full range of sizes from analytical to preparative scale. Polarity columns are designed to resist the sudden loss of retention due to dewetting, or phase collapse, when run under aqueous conditions. They feature a proprietary di-functional bonding chemistry for superior low-pH stability and long column life. Waters makes the columns with ultrapure silica to ensure exceptional peak shapes with mobile phases used in mass spectrometry analysis. For more information, contact Waters Corp., 34 Maple St., Milford, MA 01757 (phone 800-252-4752; www.waters.com).

pH Meter, the 2100, may be used to document large volumes of critical ISE, pH, or mV data sets. A 2-line dot matrix display provides clear instructions for setup and calibration. A large dot matrix display shows pH, ion, or mV readings plus temperature. The meter can send measurements to a printer or PC at timed intervals. Software allows the user to download data to a PC in a format easy to import into spreadsheet programs. The meter displays last calibration date and time and features a built-in clock with timer and alarm. It calculates and displays slope/offset of electrode automatically, and checks electrode quality and conformance to standard test method quality checks. The detachable electrode holder arm holds electrodes firmly in place. For more information, contact Oakton Instruments, P.O. Box 5136, Vernon Hills, IL 60061 (phone 888-462-5866).

--- PAGE BREAK ---

Color Measurement Instruments were exhibited by HunterLab. Their new Citrus Meter system may be used for the measurement of citrus color. It measures Citrus Number, Citrus Red, and Citrus Yellow. These indices were primarily intended to score orange juice concentrate, but have also been used for grapefruit and lemon juice. The meter is said to eliminate the subjectivity of visual methods and give reproducible objective measurements. A citrus juice sample is poured into a 1-in-diameter glass test tube, which is then inserted into the tube holder. By pressing one button on the instrument the measurement is made. CN (Citrus Number), CR (Citrus Red), and CY (Citrus Yellow) will simultaneously be displayed. The ColorFlex Citrus Meter can be connected to a printer if a hard copy of the data is desired.

The company also highlighted the Tomato Meter system for the measurement of tomato product color. The instrument measures Tomato Juice Score, Catsup Score, Paste Score, Sauce Score, and a/b ratio. As recommended by USDA, the meter’s tomato standard for scores is traceable to the UC Davis master standard. A tomato sample is poured or spooned into a sample cup, which is then placed onto the instrument measurement port. By pressing one button on the instrument the measurement is made. TJ (Juice Score), TK (Catsup Score), TP (Paste Score), TS (Sauce Score), or AB (a/b ratio) will be displayed. The meter can also be connected to a printer.

Hunter also had on display their new ColorQuest® XT self-contained transmission spectrophotometer designed to measure the transmitted color of transparent materials. Products such as resins, solvents, acids, oils, perfume, wine, beer, films, and glass can be measured. It includes widely used color scales and indices such as APHA/PtCo/Hazen, Gardner, Saybold, ASTM Color, EBC, ASBC, ADMI, and yellowness index. The unit uses a large LCD display that is back-lit and can be read in any lighting environment. The display has a touch screen that facilitates ease of operation and saves bench space. An alphanumeric keypad displayed on the touch screen simplifies sample ID and data entry. The instrument has a large sample compartment that is open on three sides for easy access and includes a transmission cell holder. For more information, contact HunterLab, 11491 Sunset Hills Rd., Reston, VA 20190 (phone 703-471-6870; www.hunterlab.com).

Microwave-Heated Column Oven is said to be a significant improvement in gas chromatography technology. By using microwaves to heat only the columns, not the surrounding air, heating and cooldown times are minimized, thus shortening each analysis. Concurrent dual-oven operation that can utilize asychronous temperature programming is also enabled inside an existing column oven. This, the company claims, can double most laboratories’ GC capabilities. For more information, contact Antek Instruments L.P., 300 Bammel Westfield Rd., Houston, TX 77090 (phone 800-365-2143 or 281-580-0339; fax: 281-580-0719).

--- PAGE BREAK ---

Chromatography Data System, called the Galaxie, was introduced by Varian, Inc. The system is said to help laboratories boost productivity and save money by linking liquid and gas chromatography (LC/GC) instruments from multiple vendors into a single, easy-to-manage network. The system was developed by the recently acquired Varian-JMBS group in Grenoble, France. For regulated laboratories, the system facilitates compliance with stringent audit, reporting, and security regulations, including 21 CFR Part 11.

Networks are becoming the standard for centralizing data management and improving laboratory efficiency. This system is a software solution for integrating all of a laboratory’s LCs and GCs into a single networked system. The scalable client/server system architecture readily expands from a single workstation to networks with hundreds of instruments as laboratory needs evolve. The company claims that fewer control workstations are needed because dedicated PCs for existing instruments are largely eliminated. Instruments are connected to the network via Star 800 Module Interface Boxes, or directly through Ethernet. In addition to simplifying network configuration, this capability saves valuable laboratory bench space. For more information, contact Varian, Inc., 2700 Mitchell Dr., Walnut Creek, CA 94598 (phone 800-926-3000).

Nitrogen/Oxygen Determinations may be made with the TC600. The unit is said to offer advanced nitrogen and oxygen determinations for a wide variety of metal and inorganic applications. The company claims that the instrument may be used for both production and research environments. It uses solid-state infrared (IR) and thermal conductivity (TC) technology and features auto high/low analyte detection, maximized sample sizing, and peripheral linking. For more information, contact Leco Corp., 3000 Lakeview Ave., St. Joseph, MI 49085 (phone 800-292-6141 or 616-985-5496; fax 616-982-8977).

Cleaning Gases with scrubbers is the purpose of Labortechnik’s Scrubber B-414. Chemical processes such as wet incineration, syntheses, or acid digestions, particularly Kjeldahl analyses, produce toxic gases and vapors as by-products. Responsible environmental behavior prohibits disposing of these products uncleaned into the atmosphere or wastewater. This scrubber can be used to capture gases and vapors close to their point of origin and neutralize them immediately. This protects both the workers in the laboratory and also the expensive equipment and fixtures there. The gas scrubbing unit is a modular 4-stage design. It can be connected to most kinds of appliances and systems and ensures environmentally compatible and efficient disposal of toxic gases. Buchi Analytical Inc., 19 Lukens Dr., Suite 400, New Castle, DE 19720 (phone 302-652-3000; fax: 302-652-8777).

by JAMES GIESE
Internet Editor