A common form of skin cancer could be diagnosed by the distinctive chemical "scent" it gives off, say U.S. experts. Philadelphia's Monell Center sampled the air directly above basal cell carcinomas and used gas chromatography-mass spectrometry to discover it was different to similar samples from healthy skin. They told a conference it offered the chance of cheap and painless testing.
A total of 22 patients, 11 with and 11 without basal cell carcinomas, were tested. All the air samples contained the same ingredients, but the equipment revealed that the patients with cancer had markedly different concentrations of certain chemicals.
The results of the project were presented at the American Chemical Society's annual conference, held in Philadelphia last week.
Read the rest of the article here http://news.bbc.co.uk/2/hi/health/7573060.stm
Monell Chemical Senses Center, http://www.monell.org/
So far, the emphasis in studies of protein folding processes has been on observation of the protein backbone and its side chains. Researchers at the Univ. of Illinois, Urbana-Champaign and the Ruhr Univ. in Bochum, Germany, changed their focus to look at the active solvent in protein folding processes: water. Using a spectroscopic technique called KITA (kinetic terahertz absorption) these scientists have been able to detect changes in the protein–water network during protein folding in real time.
Terahertz (THz) radiation consists of electromagnetic waves in the submillimeter range, putting it between the infrared and microwave ranges. Efficient sources of THz radiation are now available, making it possible to directly measure the absorption of biomolecules in aqueous buffers on the picosecond time scale. Both the skeletal movements of proteins and the collective motions of water molecules surrounding proteins occur on this time scale. What the research team demonstrated is that THz-range absorption spectroscopy is a sensitive method for the investigation of the water shell that surrounds proteins.
The abstract for the study “Real-Time Detection of Protein-Water Dynamics upon Protein Folding by Terahertz Absorption Spectroscopy” is available here.
The National Science Foundation has recently awarded $356,000 to Cindy Lee, environmental chemist and a professor of environmental engineering and earth sciences at Clemson Univ., to help figure out if hazardous PCBs (polychlorinated biphenyls) actually settle safely in sediment as many theorize. Her team is looking at how pollutants cycle through fish and other organisms and wind up on the dinner table. The research, centered on a contaminated creek near the South Carolina-Georgia border, will make use of the process of enantioselective chromatography to track the movement of PCBs, which can differ greatly in behavior on the medium, such as evaporation or microbial degradation. With the technique, mirror images of PCBs can be separated by interacting with other compounds. Separation allows the researchers to determine the quantities of each and determine if they are different. Equal amounts of each mirror image were present when the PCBs were released into the environment.
Given the fast-paced changes taking place in the world of analytical chemistry, sometimes it’s useful and instructive for professionals to step back and take stock of the technology at hand. Electronic communication helps us keep up with changes, but the infinite variety of blogs and commercial offerings can only offer snippets of what’s now available.
This, at least, is the point of view of Waters, which has recently made available an evolving electronic primer that explains the general science and recent development behind both high-performance liquid chromatography and mass spectrometry. Michael P. Balogh, principal scientist, mass spectrometry technology development, is leading the effort to build the mass spectrometry primer, a thorough overview of which he has written here.
The Journal of Mass Spectrometry has devoted its July 2008 issue to the topic of drug use in sport. Published papers detail the history of spectrometry in the Olympic Games, and a number of recent breakthroughs in both test procedures and the biological effects of supplements are detailed. One new mass spectrometry described may have an immediate impact on testing procedures.
Chemicals which add testosterone are banned by the World Anti-Doping Agency, but the exact level of the hormone varies widely between people. Simply measuring the amount from an athlete’s urine is not enough to determine whether extra testosterone has been taken. A second chemical, epitestosterone, however, is present in equal proportions to testosterone. Therefore, comparing the ratio of the two can indicate whether the hormone or a precursor has been taken. Until now, however, accurate measurement of both chemicals has been difficult.
A team of scientists the Sports Medicine Research and Testing Laboratory at the Univ. of Utah have developed a test that makes use of liquid chromatography-tandem mass spectrometry. This method has incredibly high sensitivity (down to 1 ng/ml) and increases the power with which officials can search for both testosterone and epitestosterone within a sample.
The study, “Quantitative confirmation of testosterone and epitestosterone in human urine by LC/Q-ToF mass spectrometry for doping control (p n/a),” published in the Journal of Mass Spectrometry, is available via this link, http://www.blackwellpublishing.com/press/pressitem.asp?ref=1789
There is little more highly prized than a crisp, brewery-fresh flavor, but there is nothing worse than a beer that has gone stale or sickeningly sweet from being stored too long on the shelf. For centuries the chemicals behind beer flavors have been a mystery, but new research is now revealing the elusive compounds.
Although keeping beer out of contact with air keeps some unpleasant flavors at bay, it still eventually goes bad over time. Certain flavors, like caramel, cardboard, wine, or sherry, can taste revolting when generated unintentionally.
This led Adriana Bravo and her colleagues at Polar Breweries and Simon Bolivar Univ. in Caracas, Venezuela, to hunt for other causes of flavor deterioration. The team first found that a chemical reaction called the Maillard reaction, in which sugars are broken down by reactions with amino acids, was taking place in beer sitting on the shelf. Bravo and her colleagues suspected that intermediates of the Maillard reaction, called alpha-dicarbonyls, are involved in the change in flavor
To gauge this, Bravo and her team used a technique called gas chromatography-olfactometry (GC-O), which combines the high resolution of gas chromatography with the sensitivity of the human nose. Beer was aged with and without the addition of 1,2- diaminobenzene (DAB), which isolates and identifies trace levels of particular alpha-dicarbonyls as they formed in the beer. The flavors sniffed by GC-O can identify specific chemicals in specific odors. Comparison of the flavor profiles of both beers showed that 1,2-DAB had blocked the formation of two compounds—furaneol, which smells like caramel, and phenylacetaldehyde, which smells like roses.
"How these compounds, and the many that are not yet identified, are combining to generate the aging flavours still eludes us," says Bravo, "but we are hoping to prolong the fresh beer flavour for longer by manipulating the Maillard reaction."
A team of U.S. engineers has shown that its newly-developed suspended microchannel resonator (SMR) can act as a universal detector for liquid chromatography and electrophoresis. Not only is this SMR highly sensitive but it is also microscopic, meaning that it should make an ideal detector for microchip-based separation systems.
The SMR consists of a thin strip of silicon, shaped like a diving board. It looks much like a microcantilever, which detects molecules based on the fact that they cause it to bend when they land on its surface. The SMR, on the other hand, takes advantage of the fact that a thin strip of silicon will naturally vibrate at a characteristic frequency, known as its resonant frequency.
Any particle landing on the silicon strip will alter the resonant frequency, with larger particles producing greater changes. This means that not only can the frequency change be used to detect the particle, it can also provide a measure of its mass (as low as one femtogram.
To make the SMR, a team of engineers led by Scott Manalis from the Massachusetts Institute of Technology, Cambridge, etched a tiny channel, 3 µm deep and 8 µm wide, and extended from the foot of the silicon strip up to the far end, where it turned round and came back. Manalis and his team filled this channel with fluid, allowing cells and other biological material to travel along it, but then surrounded the whole strip with a vacuum. This set-up allows the silicon strip to measure the masses of cells and other biological materials based on the changes they induce in its resonant frequency as they travel through the channel.
The abstract to the study "Suspended microchannel resonators for ultralow volume universal detection" is available here,
The abstract to the study "Weighing of biomolecules, single cells and single nanoparticles in fluid" is available here,
One oOne of the main goals in the clinical research of patients with bladder cancer is non-invasive detection of the tumors. Attempts to use mutated gene or gene products for this purpose failed mainly due to the genetic heterogeneity of bladder cancer. Metabolomic approaches are based on the assumption that pathologic conditions change metabolic pathways and are characterized by different metabolic profile compared with that of unaffected individuals.
sophisticated statistical methods scientists at the Laboratory of Proteomics and Analytical Technologies, SAIC Frederick Inc., were able to identify and characterize urine metabolite profiles obtained from patients with bladder cancer over controls. High performance liquid chromatography was used to resolve the metabolites in urine that were detected by mass spectrometry according to their mass-to-charge ratio. Mass spectrometry was selected for the study because of its sensitivity. The subsequent application of commercial statistical methods to identify the metabolites marks this technique as
The abstract to “Detection of bladder cancer in human urine by metabolomic profiling using high performance liquid chromatography/mass spectrometry,” is available here.
Two products aimed at enhancing the efficiency of process development in biopharmaceutical manufacturing are the latest offerings from GE Healthcare, a UK-based medical technology and services company.
The new launches are PreDictor 96-well filter plates and HiScreen columns prepacked with GE Healthcare's BioProcess chromatography media, which is specifically designed for industrial biotechnology. They can be used independently or as consecutive steps in a workflow to screen and optimize chromatographic conditions for bioseparations.
The PreDictor 96-well plates support high-throughput process development (HTPD), allowing parallel screening of chromatographic conditions either manually or in an automated workflow. Prefilled with defined amounts of BioProcess chromatography media, the plates can quickly evaluate up to 96 chromatography conditions for binding, washing or elution, as well as media benchmarking, with minimal buffer and sample and buffer consumption.
The HiScreen columns come with a choice of 13 different BioProcess chromatography media, such as the various MabSelect and Capto media or five different hydrophobic interaction chromatography media based on Sepharise Fast Flow.
The 10-cm bed height gives enough residence time to serve as a basis for linear process scale-up and, if needed, two columns can be connected in series to boost the bed height to 20cm. The small bed volume, says GE, keeps sample/buffer consumption small, and the incorporated media can be used repeatedly with reproducible results, scaleable to BioProcess columns packed with the same media using the same linear fluid velocity.
The forthcoming 2008 Olympic Games in Beijing, China, are focusing worldwide attention on the use and abuse of performance-enhancing drugs in sports competitions. Agilent’s technology has played a role with drug testing labs serving each of the Olympic Games as well as major events such as World Cup Soccer and the Tour de France. In addition to instrumentation, Agilent helps labs develop methods for detecting banned substances, training, technical support and servicing/maintenance of instrumentation.
The World Anti-Doping Agency (WADA) has outlined six classes of more than 400 prohibited substances:
• Stimulants, such as amphetamines and ephedrine, which are used to increase alertness and aggression while reducing fatigue;
• Narcotics, including heroin and morphine, that reduce pain sensitivity;
• Anabolic agents and steroids, which are used in a wide variety of sports to increase muscle mass and strength;
• Diuretics, which help users lose weight quickly and evade doping tests by diluting urine;
• Peptide hormones and related substances, which are used to increase muscle mass and strength and to increase endurance; and
• Other drugs that may or may not be used to enhance performance but are still restricted, such as marijuana and alcohol.
Agilent's test equipment is used by more than 50 accredited doping control centers worldwide, which provide key testing to a variety of sporting industry bodies, to help technicians screen and identify these and other banned substances. Agilent's instruments cover the three technologies that form the core of most major drug testing laboratories:
• The Agilent 7890 gas chromatograph (GC) system separates and detects components in a sample to quickly screen for prohibited substances.
• Because GC methods may not be suitable to screen for certain compounds, such as peptide hormones that cannot survive the vaporizing process, some liquid samples are screened using liquid chromatography (LC). The Agilent 1200 Series LC system separates and detects components in liquid samples, using a liquid solvent instead of a gas.
• If a banned substance is detected during screening, the sample is sent to a mass spectrometer (MS), which is generally connected to a GC or LC such as the Agilent 5975 GC/MS and the Agilent 6410 triple quadrupole LC/MS, to unambiguously confirm its chemical identity.
Scientists have come up with a whole range of different approaches for creating hemoglobin-based oxygen carriers (HBOCs) as a replacement for blood, but they all require pure hemoglobin. Now, two biomolecular engineers have developed a simple anion exchange chromatography (AEC) method for obtaining this pure hemoglobin from human and cow red blood cells, which should help to bring artificial blood a step closer to the operating table.
Although scientists have experimented with a variety of different approaches, most artificial blood is based on hemoglobin, which is the compound that transports oxygen in normal blood and the central component of red blood cells. Clearly, the easiest way to create artificial blood would be simply to extract the hemoglobin from red blood cells and then put them in some kind of solution, perhaps with a few nutrients. Unfortunately, such cell-separated hemoglobin has been found not only to be bad at transporting oxygen but also to have toxic effects on the kidney.
Guoyong Sun and Andre Palmer from the Ohio State Univ., Columbus, set about developing a simpler and quicker method. This involved using a centrifuge to separate the red blood cells from the other components of human and cow blood and then destroying the red blood cells to extract the hemoglobin. Next, the hemoglobin is subjected to gradient elution AEC, in which a salt solution is steadily added to a mobile phase consisting of a mixture of Tris (2-amino-2-hydroxymethyl-1,3-propanediol) and hydrochloric acid.
For both human and cow hemoglobin, Sun and Palmer found that this AEC method produced two just peaks in the subsequent chromatogram: a large one representing the hemoglobin and a small one representing impurities. Testing the hemoglobin fraction with gel electrophoresis and liquid chromatography/mass spectrometry, the researchers found that it comprised practically pure hemoglobin, which had similar oxygen binding properties to the hemoglobin in red blood cells.
DSM Biologics, a business unit of DSM Pharmaceutical Products, and Upfront Chromatography A/S, a leading developer of customized industrial-scale separation services, announced the collaboration between the two companies to optimize Upfront’s new, fully disposable chromatography system for use with DSM's proprietary manufacturing technology. The fully integrated disposable chromatography system will offer biopharmaceutical manufacturers significant efficiency and productivity benefits and is expected to be available for commercial use by the summer of 2008.
The combination of Upfront’s unique disposable chromatography system and DSM’s proprietary manufacturing technology will deliver a flexible, easy-to-use and high capacity bioprocessing platform that can be scaled from 0.1 L to 100 L for commercial manufacture and recovery of a range of biopharmaceuticals, including monoclonal antibodies.
Upfront’s integrated disposable chromatography system is based on its proprietary Rhobust universal processing platform. Rhobust has been implemented in a range of industrial settings for commercial-scale recovery and purification of functional biomolecules, including monoclonal antibodies, direct from crude feedstocks. A key feature of Rhobust, and in particular the disposable system, is that it does not generate pressure during operation: enabling construction of cost-effective, single-use columns from plastic. The combined advantages of disposability and crude feedstock processing has delivered a single high-yielding system which eliminates the requirement for both cleaning validation and further clarification steps, such as filtration and centrifugation.
Responding to recent reports regarding findings of trace levels of pharmaceuticals found in U.S. drinking water supplies, Waters Corp. announced on March 20 it will offer qualified U.S. water authorities complimentary drinking water analysis for common over-the-counter and prescription antidepressant pharmaceutical compounds to help assess regional exposure.
For a limited time, Waters will offer authorized officials from any U.S. water authority that serves more than 100,000 customers to submit a request for a complimentary test for common over-the-counter and anti-depressant pharmaceutical compounds of their finished water (tap water) by visiting www.waters.com/h2o. Requests will only be honored from authorized water officials and the results will be held in strict confidence.
Waters will test submitted samples using the AquaAnalysis System, which is designed to detect a range of contaminants in drinking water. The AquaAnalysis System can detect target analytes at or below 10 parts-per-trillion (PPT), meeting or exceeding regulatory standards worldwide.
The intention of these tests is to provide a baseline understanding of exposure. These tests will not be validated or certified, and are only intended as an initial screen for the detection of pharmaceutical residues.
At Pittcon 2008, ESA Biosciences Inc. showcased a new "simple and reliable" high-performance liquid chromatography (HPLC) method for simultaneous measurement of cations and anions, using its award-winning Corona CAD universal detector. This new method, says ESA, improves results for users: it is more efficient than traditional techniques because it measures anions and cations in a single run, and it is also more accurate, reliable, and cost-effective.
The traditional method for ion measurement uses dedicated, single-purpose ion chromatography (IC) systems, which must be run by highly skilled operators with specialized reagents under tightly controlled conditions. In IC, conductivity detection is used with a suppressor to reduce the background signal. Separate equipment (exchange columns and suppressors) is required to measure cations and anions. This can be cumbersome, time-consuming, and costly.
The credit for this novel ion-analysis method goes to one of ESA’s long-standing Corona CAD user, who combined the CAD's universal detection with hydrophilic interaction chromatography (HILIC). The Corona CAD-based method allows simultaneous analysis of anions and cations, says ESA, and exceeds the performance of IC with regard to measurement accuracy and reproducibility. The HILIC chromatography separates both anions and cations from complex samples for easy and reliable detection by the Corona CAD.
Driven by the spread of industrialization and the resulting rise in demand for gas chromatography testing in petrochemical, specialty chemical, natural gas, and fuel cell industries, the world gas chromatography systems market is projected to reach US$1.35 billion by the year 2010. While developing countries continue to remain important markets for gas chromatography systems, growth in the developed countries is expected to stem from the unwavering focus on addressing environmental and food safety issues.
Commonly used chemicals in consumer products, such as, PBDEs (polybrominated diphenyl ethers), a potentially toxic flame retardant chemical, is prompting GC growth in testing household consumer products such as clothing, carpets, and furniture. The trend is especially pronounced in the European Union, and the U.S. where imposition of stringent restrictions are underway. Also driving growth is proliferation of new applications especially in biotechnology and pharmaceutical sectors.
Global sales of gas chromatography systems are projected to reach 46,700 units by 2010. Asia-Pacific and Latin America are leading the growth, each having the potential for a compound annual growth rate of 4.8% and 4.6% respectively over the years 2000 through 2010. In the chemical & pharmaceutical end-use market worldwide, sales of gas chromatography systems are expected to rise by US$36.16 million between the period 2007 to 2010, with Asia-Pacific leading growth.
For details about this research report, go to: http://www.strategyr.com/Gas_Chromatography_Systems_Market_Report.asp.
Thar Instruments last week released an update to its supercritical fluid chromatography system, the Method Station II. Designed for high throughput and high resolution of drug R&D separations, the new system features a faster, higher capacity autosampler, a larger Analytical-2-Prep column oven, and new and improved software. Featuring a smaller footprint, the Method II is first new analytical product introduced as a result of the recent merger with Berger Instruments, formerly a division of Mettler-Toledo AutoChem.
A central piece of this new system is the new Analytical-2-Prep, the first column oven to accommodate multiple HPLC and SFC columns of different diameters. The oven’s drawer design provides flexibility to use up to 10 columns of two different diameters (4.6 mm and 10 mm, or 10 mm and 20 mm) simultaneously.
The oven allows users to test different phases in the separation of their drug compounds without stopping and starting the instrument to change columns.
The Method Station II integrates Chromeleon, ChemStation, and ChromScope software, and as with Thar’s other green chromatography systems utilizes CO2 as the mobile phase with a co-solvent resulting in faster equilibration, lower pressure drop and reduced solvent usage.
Agilent Technologies Inc. recently hosted the first of three leadership delegations from China's Anti-Doping Agency as China prepares for the 2008 Olympic Games. The meetings include technical training on anti-doping instruments and methods developed by Agilent, a primary supplier of technology to China's Anti-Doping Agency since 1988.
The China Anti-Doping Agency, one of the largest and most technologically advanced testing facilities in the world; will examine more than 4,500 samples from athletes during the 2008 Olympic Games. The agency has equipped its Beijing lab with Agilent liquid chromatography (LC), gas chromatography (GC) and mass spectrometry (MS) instruments to confirm the chemical identity of suspected banned substances found in testing samples. Agilent is providing 18 LC/MS units and 19 GC/MS units for drug testing at the 2008 Olympic Games.
Liquid chromatography-mass spectrometry is such a commonly used analytical technique that it can come as a surprise to realize that coupling some forms of liquid chromatography to a mass spectrometer (MS) can actually be quite tricky. This is the case with anion exchange chromatography (AEC), as the salt-based mobile phases that tend to be used in this form of chromatography, such as sodium hydroxide and sodium acetate, can suppress the MS signal.
To get around this problem, the chemists from the Université Paul Sabatier, Toulouse, led by François Couderc, decided to put a desalter after the AEC-PAD and before the MS. As its name suggests, a desalter (also known as a suppressor) effectively removes salt molecules from the mobile phase. It consists of a tubular polymer membrane through which flows the mobile phase with the separated carbohydrate molecules, while a hydrogen ion-containing liquid such as sulphuric acid flows in the opposite direction over the outside of the membrane.
The idea is that hydrogen ions flow from the sulphuric acid across the membrane and into the mobile phase where they displace the sodium ions in the sodium hydroxide and sodium acetate molecules, transforming them into water and acetic acid respectively. Neither of these molecules has any detrimental effect on the MS signal, with acetic acid actually enhancing the MS signal by assisting with the fragmentation and ionization process.
In order to get this system to work, Couderc and his team realized that they had to set it up in a linear fashion, with the MS placed after the PAD and the desalter between them, if they wanted to keep the PAD. This is because polysaccharides are often present at such low concentrations in biological samples that splitting the mobile phase eluting from the AEC into two streams, and then sending one to the PAD and the other to the MS, could reduce the concentrations to below detectable levels.
But on testing their system on a specially-prepared mixture of polysaccharides, Couderc and his team found that this linear set-up had an additional advantage.
"It is important to maintain PAD detection, because it is sensitive and its response is complementary to MS," explains team member Véréna Poinsot. "The acidic sugars are not well detected by PAD but are very sensitively detected by MS, while the opposite is the case for neutral sugars."
After these successful tests, the chemists used their AEC-PAD/MS system to analyze the polysaccharides found on the surface of various species of Sinorhizobia.
Biopsies are important in the detection of cancerous and precancerous lesions, but they are painful, require anesthesia, and can leave scars. A new tool may remove the needles and blades involved, replacing them with a noninvasive, handheld scanner. A researcher at Australia’s Queensland Univ. of Technology (QUT) developed the “virtual biopsy” tool. It is a small device, about the size of a credit card, which is simply waved over a suspicious lesion. The tool uses bioimpedance spectroscopy to detect changes in the tissue.
Bioimpedance spectroscopy is the same technology used at the gym to determine the percentage of lean mass and fat in your body. Small electrical currents are sent through the body, reacting differently depending upon the composition of the underlying tissue. Computers interpret these currents and use it to provide information about what’s going on beneath the skin.
"It has only recently been applied to biological tissue to determine healthy, cancerous or dead cells," says developer Jye Smith from QUT's School of Physical and Chemical Sciences. "It offers the possibility of a simple device that can be run over the surface of the skin or internal organ that can quickly, cheaply and accurately record changes in cellular structure that point to cancerous changes."
The new device detects changes at the cellular level. The developer of the device says it can detect changes within cells, in their membranes, and in the tissue surrounding them. Because cancer cells look different and are composed of different material than healthy cells, predictable patterns can be developed and used to predict if a lesion is cancerous, before a biopsy is performed.
This may turn out to be a useful screening tool in dermatology, gynecology and general practice offices, where numerous skin and cervical biopsies are performed in an effort to detect and treat cancerous lesion.
"The beauty of this technique is that the patient doesn't need an anaesthetic, the data is immediate, and it has the potential to be as accurate as more time-consuming, expensive techniques,” says Smith.
He says further development of the technique could very well see it make its way into GP practices or skin clinics.
Electronic Sensor Technology (EST), maker of homeland security and environmental solutions, said this week it has received orders from two different universities for use in plant biology research projects.
One university will use EST’s gas chromatography device zNose in the Peruvian Rain Forest to better understand the chemical and biochemical processes in the rhizosphere, which is the area surrounding plant roots and includes other plants, microbes, invertebrates and the soil. The mission of the department is to study the rhizosphere in order to develop new antibiotics, anticancer drugs, and bio-friendly pesticides.
The second university's program will use the zNose to measure chemicals produced by plants in order to monitor their health. When plants are under stress from disease or pest infestations, they generate a chemical response. The zNose is able to measure this chemical response and facilitate detection of plant stress before it becomes visible to the eye. This will allow timely remediation efforts to take place in order to minimize crop damage.
EST did not identify the universities which had ordered the zNose. Earlier this month, four similar zNose devices were ordered through the company’s Kuwait distributor for use in security in the Middle East. According to the company, the zNose detects traditional and liquid explosives.
The zNose is part of EST’s line of chemical vapor analyzers. The ultra high-speed gas chromatography is coupled with a solid state detector to enable analysis of nearly any odor, fragrance, or chemical vapor within 10 seconds.
Germany's rap.ID Particle Systems has launched a new lab-ready particle identification device capable of identifying around 400 particles an hour from 5 µm and up. The company says the device is suited for development and quality assurance in the pharmaceutical industry.
The Advanced Single Particle Explorer (ASPE) aims to vastly speed up a process that is currently stifling research, adding to costs in an already budget conscious sector. According to the company, conventional lab needs about a week to chemically identify the 20-40 largest contaminating particles. The process alone can cost up to $6000.
With the new device, rap.ID Particle Systems claim to deliver the same results in 25 minutes, needing only 3 minutes to filtrate the sample using the filtr.AID Membrane. The sample is then loaded into the machine, analysis mode selected and pressing start to begin the process. The device's automated image analysis feature, coupled with Raman spectroscopy results in the measurement of size, count, and shape of over 10,000 particles from 5 µm and up.
The device is able to quickly identify the two general types of contaminants normally found in the pharmaceutical research and quality assurance processes, separating them from non-hazardous particles.
The ASPE uses a four-fold sample changer for routine studies. For more information, go to: www.rap-id.com/
A new process gas chromatograph from Siemens Automation and Drives (A&D) is specifically designed to determine the calorific value of natural gas. The Sitrans CV finds application in pipeline monitoring, gas transfer and distribution, gas liquefaction and re-gasification of LNG terminals. The device has a rugged and explosion-proof housing, is compact and suitable for use in extreme conditions from -20 to +55°C. The unit can be mounted directly next to natural-gas pipelines and delivers measured results in less than three minutes.
A primary application of the Sitrans CV is the monitoring of natural gas under custody transfer. The chromatograph determines the quality of natural gas in terms of Wobbe index, calorific value and density, parameters which play an important role in the varied applications of the natural-gas industry. They are particularly important when monitoring the quality of gas under custody transfer. Measurement accuracy is independent of sample pressure or ambient temperature and results can be displayed directly on the device. The instrument uses miniaturized detectors and valves made using micro-electro-mechanical systems (MEMS) technology, resulting in minimal consumption of carrier gas and electricity and eliminating the need for analyzer sheltering. The detectors are highly linear requiring only one calibration gas, which means reduced operating costs and increased availability. Automated optimization of measuring parameters at calibration time ensures a high degree of accuracy and reliability.
Waters Corp. and Vanderbilt Univ. Medical Center this week began collaborative research efforts using Waters MALDI Synapt high definition mass spectrometry (HDMS) system for enhanced tissue imaging capabilities for oncology research within the university's Mass Spectrometry Research Center.
Researchers at the medical center are focused on new mass spectrometry (MS) approaches to identify and visualize protein expression changes in cells as they transition from a healthy state through various stages of cancer.
"The goal of tissue imaging is to provide a window into the changes in the cellular proteome in disease," says Prof. Richard Caprioli, director of Mass Spectrometry Research Center at Vanderbilt Univ. Medical Center. "We look forward to evaluating the use of ion mobility for enhanced MALDI imaging combined with high resolution, high sensitivity, orthogonal time-of-flight (Tof) mass spectrometry. Ultimately, we hope that enhanced tissue imaging techniques will provide data sets to be mined for diagnostic and prognostic information related to the various stages of cancer."
The Synapt HDMS system is being used because it features high efficiency ion mobility separation in a dual ionization mass spectrometer.
An international conference on “Perspectives in Vibrational Spectroscopy” is being held in Kerala, India, this week, drawing in a host of participating scientists from various countries. The scientists will be speaking on recent developments in Raman spectroscopy, named after India’s physicist Nobel laureate C.V. Raman eight decades ago.
Raman spectroscopy is predominantly used in condensed matter physics and chemistry to study vibrational, rotational, and other low-frequency modes. However, it’s versatility has allowed to become a tool for advanced studies in new materials, molecular dynamics, and space exploration.
“This conference seeks to provide a global platform for the research community in Raman spectroscopy to discuss the recent developments in the field,” says Professor V.S. Jayakumar, convenor of the five-day meet which lasts through Feb. 29.
MIT's George R. Harrison Spectroscopy Laboratory will be holding an event, "MIT's Spectroscopy Laboratory: The Next 80 Years," to celebrate its new space, on Wednesday, Feb. 27. The event, which runs from 9:30 a.m. to 3:30 p.m., includes talks, tours of the renovated laboratories, and a luncheon.
Speakers for the morning session include Subra Suresh, dean of MIT's School of Engineering, who will talk about multidisciplinary research at the intersections of engineering, sciences and medicine. Other speakers include Phil Bucksbaum of Stanford and Xiaowei Zhuang of Harvard.
From March 1-7 at the Ernest N. Memorial Convention Centre, New Orleans, Fortis Technologies will be presenting new solutions in high-performance liquid chromatography (HPLC) column technology, including a new 2.1 µm particle for use in ultra HPLC.
Fortis C18 is a silica based phase which operates across the entire pH range low, mid and high, to optimize the operation of Jasco X-LC, Agilent 1200 or Acquity UPLC LC systems. The 2.1 µm particles can be used in gaining resolution and sensitivity under correct operating conditions, isocratic conditions, long columns (>100 mm), and shallow gradients.
Other new products include Fortis Phenyl, a unique di-phenyl functionality providing high-performance separation capacity, as well as being a "non-bleed" phenyl phase.
Engineers at Massachusetts Institute of Technology are developing a tiny sensor that could be used to detect minute quantities of hazardous gases, including toxic industrial chemicals and chemical warfare agents, much more quickly than current devices.
The researchers have taken the common techniques of gas chromatography and mass spectrometry and shrunk them to fit in a device the size of a computer mouse. Eventually, the team, led by MIT Professor Akintunde Ibitayo Akinwande, plans to build a detector about the size of a matchbox.
"Everything we're doing has been done on a macro scale. We are just scaling it down," says Akinwande, a professor of electrical engineering and computer science and member of MIT's Microsystems Technology Laboratories (MTL).
Akinwande and MIT research scientist Luis Velasquez-Garcia presented their work at the Micro Electro Mechanical Systems (MEMS) 2008 conference earlier this month. In December, they presented at the International Electronic Devices Meeting.
Scaling down gas detectors makes them much easier to use in a real-world environment, where they could be dispersed in a building or outdoor area. Making the devices small also reduces the amount of power they consume and enhances their sensitivity to trace amounts of gases, Akinwande says.
He is leading an international team that includes scientists from the Univ. of Cambridge, the Univ. of Texas at Dallas, Clean Earth Technology and Raytheon, as well as MIT.
Their detector uses gas chromatography and mass spectrometry (GC-MS) to identify gas molecules by their telltale electronic signatures. Current versions of portable GC-MS machines, which take about 15 minutes to produce results, are around 40,000 m3, about the size of a full paper grocery bag, and use 10,000 J of energy.
The new, smaller version consumes about 4 J and produces results in about four seconds.
The device, which the researchers plan to have completed within two years, could be used to help protect water supplies or for medical diagnostics, as well as to detect hazardous gases in the air.
The analyzer works by breaking gas molecules into ionized fragments, which can be detected by their specific charge (ratio-of-charge to molecular weight).
Gas molecules are broken apart either by stripping electrons off the molecules, or by bombarding them with electrons stripped from carbon nanotubes. The fragments are then sent through a long, narrow electric field. At the end of the field, the ions' charges are converted to voltage and measured by an electrometer, yielding the molecules' distinctive electronic signature.
Shrinking the device greatly reduces the energy needed to power it, in part because much of the energy is dedicated to creating a vacuum in the chamber where the electric field is located.
Another advantage of the small size is that smaller systems can be precisely built using microfabrication. Also, batch-fabrication will allow the detectors to be produced inexpensively.
The research, which started three years ago, is funded by the Defense Advanced Research Projects Agency and the U.S. Army Soldier Systems Center in Natick, Mass.
The U.S. Centers for Disease Control and Prevention (CDC) has changed the way it measures dietary phytoestrogens in urine thanks to work conducted by three of its researchers. They discovered that the sensitivity and precision of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analyses of urinary phytoestrogens can be improved by simply using a slightly different ionization technique.
Phytoestrogens are plant-derived polyphenolic compounds such as isoflavones, lignans and stilbenes that are found in a wide-range of foodstuffs, especially nuts, soy products, cereals and breads. They are biologically-active compounds and have been linked to a wide range of beneficial health effects, such as protecting against various cancers, cardiovascular disease and bone damage. But, as their name suggests, they are also structurally similar to steroid oestrogens, which are known to cause a variety of reproductive problems in many organisms via endocrine disruption. So the overall health effects of consuming phytoestrogen-rich food are still unclear.
Because of this, the CDC regularly measures the concentration of phytoestrogens in human urine samples as part of its health monitoring projects, such as the National Health and Nutrition Examination Survey (NHANES). It does this by measuring six specific phytoestrogens—the isoflavones equol, daidzein, genistein and O-desmethylangolensin and the lignans enterodiol and enterolactone—using HPLC-MS/MS with atmospheric pressure chemical ionization (APCI).
However, CDC researchers have discovered that this method is poor at detecting certain of these phytoestrogens, especially equol, which is unfortunate because equol is a fairly unusual phytoestrogen.
“Equol is a compound of significant interest in the epidemiological literature due to its purported health effects,” explains Michael Rybak from the CDC. “[It] also has the unique characteristic of being a mammalian phytoestrogen, i.e. it is metabolically generated in the body from daidzein, a phytoestrogen found in foods such as soy.”
When using HPLC-MS/MS with APCI, the CDC researchers found that they were only able to detect equol in around 75% of urine samples. According to Rybak, this is “unacceptably poor for biomonitoring purposes” and so, together with two colleagues, he set about trying to improve the sensitivity of this analytical method.
The most straight-forward way to do this is to use a different ionization technique and so Rybak and his team decided to try electrospray ionization (ESI).
“ESI and APCI are probably the two most commonly used ionization mechanisms for LC-MS/MS,” says Rybak, “and often both are available on the same instrument using the same interface, as was the case in our laboratory.”
In both APCI and ESI, the liquid HPLC effluent is initially transformed into an aerosol spray. But in APCI the analytes in this spray are then ionized by exposing them to a powerful electric field, whereas in ESI they are ionized via the evaporation of a volatile solvent. ESI is a gentler ionization method than APCI, being less likely to cause the analytes to fragment, and is generally used for polar compounds that can be ionized in solution, while APCI is used for non-polar compounds than can undergo acid-based reactions in the gas phase.
Rybak and his colleagues tested the abilities of APCI and ESI by using both ionization techniques with HPLC-MS/MS to analyze the concentrations of the six phytoestrogens in over 350 human urine samples. They discovered that while APCI and ESI gave broadly similar results, ESI could detect lower concentrations of three of the phytoestrogens—equol, enterodiol and genistein. This effect was most pronounced for equol, with ESI able to detect this phytoestrogen at levels as low as 0.3 ng/mL. In contrast, the limit of detection for APCI was 2.7 ng/mL.
Although Rybak is unsure as to why ESI performs better than APCI at detecting these phytoestrogens, his findings have already caused the CDC to switch over to ESI. “We now use ESI in measuring urinary phytoestrogens for NHANES and other studies,” Rybak says.
According to scientists at the Technical Univ. of Denmark, the use of pure SO2 in waveguides increases sensitivity by one to two orders of magnitude and promotes the effective use of ultraviolet light in micro-analytic devices.
Klaus B. Mogensen, Omar Gustafsson, Pedro Nunes, and Jörg P. Kutter of the Department of Micro- and Nanotechnology have researched the capabilities of miniaturized lab-on-a-chip systems and have developed a microfluidics chip that demonstrates their claims.
Microfluidics chips, their report says, have the advantage of lowering sample volume, decreasing analysis time, and in some cases enabling portability. By the same token, a complication of the reduced channel volume is that, especially in detection of absorbed light, sensitivity is compromised because it is proportional to the optical path length. The use of external bulk optics typically allows adequate response only through a depth of 10–100 µm. For this reason researchers generally use fluorescence detection in lab-on-a-chip applications because it is very sensitive over small volumes. The problem with this approach is that labeling (as with fluorescent dyes) alters the properties of the analytes, which makes the results difficult to interpret. Hence, fluorescence detection is used in only around 1% of all high-performance liquid chromatography (HPLC) analyses, while UV absorbance detection is used in around 94% of applications.
Optical waveguides are structures that combine components of different refractive indices to steer light along their length. The researcher’s approach for making UV absorbance available for microchip chromatography is to use integrated waveguides for detection in the plane of the device and thereby along the length of a channel segment.
The result is a chip for electro-chromatography that uses a waveguide with absorbance detection in the UV range. The path length is 1000 µm, which increases sensitivity one to two orders of magnitude compared with free-space optics. The waveguides are made of pure silicon dioxide with air as the side and top cladding, and were measured to be transparent down to at least 200 nm.
The researchers’ work marks the first time capillary electrochromatography has been shown on a microchip with integrated waveguides for detection. In addition, the scientists say the waveguides are the most transparent in the UV reported to date. In the future they plan to optimize the separation performance of the chip by reducing the size of the pillars in the column, and to lower the detection limits by replacing the bulky mercury arc lamp with a small UV laser.
Nanotechnology researchers have spent the past few years developing a whole range of methods for separating different types of single-walled carbon nanotube (SWNT), from centrifuging them in a density gradient to attaching diazonium salts and then separating them by electrophoresis. But it now looks as though ion exchange chromatography (IEC) might provide the best solution, not just being able to separate metallic SWNTs from semi-conducting SWNTs but able to separate every type of SWNT according to its specific electrical properties.
SWNTs are tiny tubes of carbon with walls only one atom thick, as though a single sheet of graphite has been rolled into a tube. They have a number of useful properties, including various electrical and optical properties. The precise nature of these properties are dictated by the alignment of the carbon bonds in the tube (or, in other words, by the direction in which the graphite sheet is rolled up) and by the tube's diameter.
These two features of SWNTs can be represented by a pair of integers (n,m) that essentially describe the number of carbon molecules along two directions of the graphite sheet forming the tube. When n=m, the SWNTs are known as armchair; when n or m equal zero, the SWNTs are known as zigzag; and when n and m take any other non-identical values, the SWNTs are known as chiral. All armchair SWNTs have metallic properties and are able to conduct electricity very efficiently, whereas both zigzag and chiral SWNTs are semi-conductors, with the precise level of conductivity depending on the specific values taken by n and m.
Although there is great excitement over the use of SWNTs in the next generation of electrical devices, this will require being able to supply SWNTs with specific electrical properties.
Unfortunately, current production techniques, which generally involve growing SWNTs by passing a carbon-based gas such as methane over metal catalysts, can only produce a broad selection of SWNTs with various n and m values. Hence the interest in developing methods that can separate and isolate different types of SWNT.
So far, most of these methods have concentrated on separating metallic SWNTs from semi-conducting SWNTs. But the ultimate goal is to be able to separate SWNTs according to their specific n and m values. In 2003, a group of researchers from DuPont Central Research and Development at Wilmington, the University of Illinois at Urbana-Champaign and the Massachusetts Institute of Technology showed how this might be achieved with IEC.
They found that a specific DNA strand composed entirely of the bases guanine and thymine would naturally bind with SWNTs and that the resultant DNA-SWNT hybrids could then be separated by anion exchange chromatography (AEC) according to the SWNTs' electrical properties. The researchers proposed that this separation mechanism depended on variations in the electrical densities of the DNA-SWNT hybrids, which influenced how strongly they bonded with the AEC stationary phase. These variations are most likely a function of the way in which the negative charge of the phosphate groups on the DNA backbone are modulated by the specific electrical properties and diameter of the SWNTs.
Since then, a number of groups have built on this finding to perform ever more sensitive SWNT separations. In 2007, two DuPont researchers combined this IEC separation technique with size-exclusion chromatography to separate (9,1) SWNTs from (6,5) SWNTs, which have the same diameter but different molecular alignments.
Most recently, researchers from Stanford University, California, and the University of Arkansas combined this IEC separation technique with a novel iron-ruthenium catalyst that is able to produce a very narrow range of SWNT types. Growing SWNTs at 850°C, the researchers discovered their novel catalyst produced just four different types of semi-conducting SWNT (with different n and m values), which they were then able to separate from each other using the IEC separation technique.
So thanks to IEC, the day of being able to pick and choose SWNTs with defined electrical properties may soon be upon us.
A more accurate method to measure iron in clinical samples is proving ahead of its time, say researchers in Spain.
The group at the Univ. of Oviedo in Spain, led by Alfredo Sanz-Medel, has developed a technique that allows many variables that can indicate iron-related disease to be measured simultaneously and with great precision.
"Iron is used in numerous enzymes and processes throughout the human body. Any imbalance in the amount of iron in the body can lead to disease,” says Sanz-Medel.
But many different parameters need to be measured to detect such pathologies - since the metal is used not just as an oxygen transporter in the blood but also in numerous enzymes and processes throughout the human body. Until now these parameters have had to be measured separately, often needing multiple steps.
Sanz-Medel's method avoids this and uses transferrin (Tf), a blood plasma protein that transports iron around the body, to measure iron levels in serum. The group saturate the transferrin with either naturally-occurring iron or a non-radioactive isotope and use high performance liquid chromatography (HPLC) and inductively coupled plasma-mass spectrometry (ICP-MS) techniques to measure the amounts of the metal and protein. By comparing the iron isotope ratios, the data can be used to extrapolate clinically useful parameters including the amount of iron bound to Tf and unbound in serum.
Group member María Montes-Bayón explained the team's approach: 'A great number of biomedical applications use radioactive isotopes. The main advantage of stable isotopes, especially for in vivo studies, is that it means no radiation hazard for the patients.'
Zoltan Mester, an expert in using mass spectrometry in isotope ratio analysis, from the Institute for National Measurement Standards in Ottawa, Canada, described the work as a 'dramatically new approach for the study of iron homeostasis.' In fact, the work is so novel that Montes-Bayón admits that the challenge now is to convince the medical community that 'new and more specific tests are necessary to detect increasing numbers of diseases.' With this aim, the group is now looking to start collaborating with biochemists and medical doctors to further the work.
Waters Corp. recently released the latest iteration of its Waters Synapt MS system, a next-generation quadrupole orthogonal acceleration, time-of-flight (TOF) mass spectrometry (MS) platform.
According to the company, the instrument is a key part of a strategy to enhance the quality and productivity of life science and drug discovery and development workflows.
Additionally, the Synapt MS system is the only platform which provides an upgrade pathway to the Synapt high definition mass spectrometry (HDMS) system, enabling researchers to analyze samples differentiated by size, shape and charge, as well as mass, ultimately providing new capabilities that can help them meet and exceed future requirements.
“Confident sample identification, detailed characterization and increased productivity are primary requirements for intelligent mass spectrometry-based solutions in key biomedical applications such as proteomics, metabonomic profiling, biomarker discovery/validation and pharmaceutical R&D,” says Brian W. Smith, vice president, mass spectrometry operations for the Waters Division. “The new SYNAPT MS meets these demands through application specific system solutions designed to help our customers accelerate and improve the quality of laboratory analysis with the goal of advancing research and reducing time-to-market.”
Synapt MS combines several different Waters technologies: Acquity ultra-performance liquid chromatography (UPLC) separations, Exact Mass MSE data acquisition, and MassLynx informatics.
For example, the Synapt MS allows researchers to perform matrix-assisted laser desorption ionization (MALDI) imaging to determine the spatial localization of drugs, metabolites and peptides in biological tissues with high specificity and sensitivity. This can enable greater numbers of candidates to be evaluated in the drug discovery phase, leading to more rigorous selection of compounds for ongoing development.
Waters believes the Synapt MS does another service to customers by giving them the ability to upgrade to HDMS.
For more information on Waters SYNAPT High Definition MS System, visit www.waters.com/HDMS.
Millipore Corp., a provider of tools and services for the bioscience research and biopharmaceutical manufacturing industry, this month introduced a new online resource for the preparation of samples and solutions used in Ultra-High Performance Liquid Chromatography (UHPLC).
The Web site provides technical information on Millipore’s UHPLC-related products, as well as data for buffer filtration, solvent filtration and sample preparation. Millipore provides syringe filters, membranes and holders in many configurations that are designed and manufactured to maximize UHPLC system performance. These devices minimize column clogging and have low extractables, low binding and low hold-up volumes to optimize sample preparation. Lab water systems are also available that provide ultrapure water for all aspects of UHPLC from mobile phase preparation to standards, blanks and samples.
Chiral separation has become one of the most important application areas in high-pressure liquid chromatography (HPLC), including the use of ultra-HPLC (X-LC). The increasing demand for chiral chromatography in various fields, such as drug analysis, drug discovery, biochemical analysis, natural product analysis, organic synthesis, etc. have resulted in a parallel demand for optimized chiral separations and more sensitive detection methods. Recent advances in chiral column technology are boosting the use of chiral chromatography in a greater number of laboratories; however, advances in chiral detection technology have only recently met the required demands in terms of sensitivity and selectivity.
Circular dichroism (CD) is based upon the differential absorption of right and left circularly polarized light as a result of a chiral chromaphore and is a much more specific technique than optical rotation (OR) or polarimetry techniques. CD detectors can provide a negative or positive signal based on the chirality of the eluting molecule, thus providing positive identification of the molecular chirality, unlike conventional ultraviolet, refractive index or fluorescence detectors which cannot differentiate between the chiral molecules.
Jasco developed the new 3195CD Circular Dichroism Chiral Detector as an innovative CD detector for HPLC systems including its own U-HPLC X-LC systems, using the same technology applied in conventional CD spectropolarimeters. The 3195CD enables highly sensitive and selective detections of chiral compounds, simultaneously determining both the CD and UV absorption of the sample in the same cell, and determines optical isomer separation and purity. To meet X-LC requirements, the 3195CD features a high speed sampling rate of 50 data points/sec, for both the CD and UV signals, and the specially designed flow cell minimizes peak broadening.
Varian Inc. this month launched their new 920-LC liquid chromatograph, an automated, computer-controlled analytical high-performance liquid chromatography system. The instrument is designed for pharmaceutical, environmental and industrial laboratories for the separation, detection, and characterization of chemical compounds and mixtures. The low dead volume, pulse-free performance and precise solvent proportioning valves make the Varian 920-LC suitable for "fast LC".
The device comes with a choice of built-in, programmable dual-wavelength or information-rich diode array (190-900 nm) UV-Vis detectors feature low noise and high sensitivity to deliver lower detection limits for trace analysis. Optional fluorescence, refractive index, and evaporative light scattering detectors allow a wide variety of analyses to be performed with the 920-LC.
For more technical information about Varian's HPLC instrumentation, visit
http://www.varianinc.com/products/
SOURCE: Varian Inc.
Editor's Take
Recycling on the ISS
November 17, 2008
As the astronauts offload the cargo from the Shuttle Endeavour to the ISS today to facilitate growing the crew from three to six astronauts, one item in particular is getting a lot of press: the new toilet. This is not just any toilet: this is a $250 million loo that will recycle the astronauts’ urine, sweat, and other wastewater back into drinkable water. This is a great application of technology and could cut the annual delivery water costs for the station by about 743 gallons, according to NASA officials. Besides which, this filtering process is just an accelerated version of what happens here on Earth to produce our drinking water. In fact, the water from this system is up to some of the highest standards of water in the U.S.
With all of that said, I’m not sure I’d be able to stomach the recycled water, especially after reading Endeavour’s mission specialist Don Pettit’s description of the system as a high-tech coffee maker: "It turns yesterday's coffee into today's coffee and, in turn, it makes today's coffee into tomorrow's coffee. It's one of these great, circle of life things." Maybe for the astronauts, but not for me. I’ll take my morning coffee without thinking about what it was yesterday, thank you.
