A team of scientists from Curtin University recently revealed a reliable method of determining the sources of volatile organic compounds (VOCs) in Perth’s atmosphere. This new method, which involves thermal desorption, gas chromatography (GC), and isotope ratio mass spectrometry (IRMS), was used by the researchers to analyze carbon and hydrogen isotope values of VOCs in various emission sources throughout the area.

Results of this investigation were then compared to those taken from one of Alcoa Australia’s local aluminum refineries, where sources of organics are different.

VOCs are hydrocarbons which can be emitted through transportation, burning, microbial production, and emissions from various plants. These compounds are also determined by an adequate vapour pressure to enter the atmosphere.

“The paper focuses on the actual values of VOCs emitted from direct source points—diesel sources, combustion of the different vegetation types C3 versus C4 plants, and emissions from an industrial source,” says Kilti Grice, Curtin University’s WA-Organic and Isotope Geochemistry Centre director. She also explained that the study aimed to establish if 13C/12C (heavy/light carbon ratios) and D/H ratios (natural abundance ratios) of complex mixtures of VOCS can be accurately measured via the thermal desorption technique.

Results of the study showed that indeed, the sources of VOCs could be reliably determined by using the thermal desorption method on the emission samples taken.

In order to substantiate findings, the researchers suggest expanding the range of emission sources to different car models, other industry fields and bush or forest fires. To guarantee accurate results, scientists should only use efficient, industry-standard gas chromatography systems. For inquiries on a high-quality gas chromatography system for your facility, fill out the form at the left.

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A team of Italian researchers recently discovered that a simple experimental breath test can diagnose colorectal cancer with over 75% accuracy. Results of the study, which were determined using thermal-desorber gas chromatography-mass spectrometry (GC-MS), showed that the exhaled breath of cancer patients contained volatile organic compounds (VOCs) different from those in people without cancer. The study has been published in the British Journal of Surgery.

The method works by detecting VOCs emitted by cancerous tissue, a technique that has been used in diagnostics for several cancers and gastrointestinal disorders. The researchers collected exhaled breath samples from 37 people with colorectal cancer and 41 people without. The breath samples were then evaluated using thermal-desorber GC-MS to find traces and patterns of VOCs that might indicate cancer.

Findings indicate that a pattern of 15 VOCs was linked with colorectal cancer. These patterns discriminated cancer cases with 86% sensitivity, 83% specificity, and 85% accuracy. Final results showed that 19 of the people with colorectal cancer were correctly diagnosed with colorectal cancer from their breath samples.

According to lead author Dr. Donato F. Altomare, M.D. of the University Aldo Moro of Bari, the study’s findings “provide further support for the value of breath testing as a screening tool.” With this, researchers interested in extending the current use of breath tests now have additional reference with regards to the limitations of the method. To achieve accurate results, such research require the use of reliable and industry-standard gas chromatography systems. For any inquiries on high-quality GC systems, feel free to fill out the form at the left.

Scientists from the German Research Center for Food Chemistry used headspace gas chromatography-olfactometry (HSGC-O) and aroma extract dilution analysis to determine the unique aroma compounds of durian. This study was recently published in the ACS’ Journal of Agricultural and Food Chemistry.

Although regarded as the “king of fruits” in Southeast Asia, the durian is widely disliked in other countries because of its foul odor. Past research has identified 200 volatile substances in the durian, but no claims have been made as to which of these substances directly contribute to the durian’s unique smell. Led by Martin Steinhaus, this recent study aimed to fill in this research void.

Through aroma extract dilution analysis, the researchers identified 41 highly odor-active compounds, 24 of which had not been identified in durian before. After screening the compounds using HSGC-O, they found that the most prominent substances were associated with fruity, sweet, sulfurous, and oniony smells – the oniony smelling odorants belonging to a compound class rarely found in food. Moreover, four of the newly discovered chemical compounds were reported for the first time in scientific research.

The production of flavorants used by the food service industry to flavor and improve their products mainly relies on the aroma compounds discovered in natural food. This study to determine the compounds of the durian opens new possibilities and opportunities for manufacturers to improve their durian products. For similar studies involving different natural foods, scientists and researchers should only use high-quality gas chromatography systems to accurately identify aroma compounds. For inquiries on top-grade gas chromatography systems for your facility, fill out the form at the left.

An international team of scientists from various cancer institutes used gas chromatography (GC) in their recent study to determine the reason behind the unusually high incidence of esophageal cancer in Western Kenya.

Esophageal cancer is commonly associated with heavy drinking and tobacco smoking. However, despite the low prevalence of these typical risk factors among Kenyans, esophageal cancer remains to be a common disease among them.

The researchers hypothesized that the consumption of fermented milk – an old tradition among Kenyans – contributes to the high frequency of esophageal cancer. They stated that it was possible that alcohol and acetaldehyde are produced during the fermentation process, and that esophageal cancer is triggered by the carcinogenic potential of these compounds.

The team gathered eight samples of mursik milk starter cultures from different Kalenjin families in the Rift Valley province, Western Kenya. The families’ traditional procedure was used for milk fermentation. The ethanol and acetaldehyde levels of the fermented milk were measured by GC, while microbial flora in starter cultures was identified by 16S and 18S sequencing.

The research team was composed of scientists from the Research Unit on Acetaldehyde and Cancer from the University of Helsinki, the School of Translational Medicine from the University of Manchester, the National Cancer Institute, Tenwek Hospital, the Division of Cancer Epidemiology and Genetics, and the Nutritional Epidemiology Branch.

Many diseases have already been associated with the ingestion of dangerous compounds found in food, and as more and more food products are introduced in the market at incredibly fast rates, scientists and nutritionists alike are faced with the challenge of determining which of these foods are safe enough for long-term consumption. To do this, scientists only use top-quality gas chromatographs in their research to ensure the accuracy of their data. For any inquiries on high-quality gas chromatography systems, feel free to fill out the form at the left.

A team of researchers from the Centre for Taste and Food at the University of Burgundy, France used gas chromatography—olfactometry (GC-O) and gas chromatography—mass spectrometry (GC-MS) to screen and identify the aroma compounds of aromatic caramel. (GC–MS).

Aromatic caramel, which is obtained by the controlled heat treatment of sugar, is most commonly used in the food industry because of its rich aroma and pleasant organoleptic properties. However, the typical compounds that make up the odorant fraction of aromatic caramel have yet to be fully identified. To shed light on this, the researchers studied four distinct aromatic caramels which differed in terms of carbohydrate composition and cooking process.

Odorant compounds from each type of caramel were screened using GC-O and identified using GC-MS. Quantitative GC-O and sensory data sets were then analyzed using partial least squares (PLS) regression. This was the first attempt of using PLS to link the odorant compound frequencies and caramel aroma sensory profiles.

After the process, the researchers found 76 odorant zones and 49 aroma compounds. Odorant properties are closely related to the volatile fraction of caramel, but only a few compounds are responsible for the aroma it exudes, the researchers explained. Researchers also found that the caramel’s odor properties were strongly related to its cooking properties. Descriptive profiling of the aromas was also conducted with the help of ten trained assessors.

“Aroma is one of the main factors that contribute to the consumer acceptability of a food product,” the team stated. The results of this study constitute to a better understanding of the caramel odor, and contribute to possible developments in the food industry.

This study is in fact the first of its kind, and is expected to encourage scientists and researchers in similar fields to investigate the sensory profiles of different types of food. In order to do this, scientists will need high-quality gas chromatography systems. For inquiries on a high-quality gas chromatography system for your facility, fill out the form at the left.

A team of Japanese researchers has recently conducted a study to analyze fluids in survivors of body-packer syndrome in Japan using gas chromatography. Serum, plasma, and urine samples were collected from three patients assumed to be body packers, and who were also referred to hospitals between 2010 and 2011. Concentrations of stimulants were extracted from the samples with solid-phase columns and were analyzed using gas chromatography tandem mass spectrometry (GC–MS).

Wrapped, cylindrical packets of foreign bodies were detected in the intestinal tracts of all three patients via plain X-ray (X-P) and computed tomography (CT)—all of which were then removed through surgery.

The first patient experienced convulsions and tachycardia upon admission to the hospital, and one of the removed packets was discovered to have ruptured. The second patient appeared to have an intestine block caused by the packets on the third day, though he presented no symptoms and the removed packets did not appear to have ruptured. The third patient showed restlessness on the first day, and one of the removed packets was confirmed to have ruptured.

Results of the study showed that methamphetamine (MA) and amphetamine (AP) were present in the serum, plasma and urine of all three patients. The researchers were also able to confirm that the serum and plasma concentrations of MA were high in patients that manifested symptoms of MA intoxication. MA and AP were also detected in the patient who showed no symptoms of intoxication and whose packets had not ruptured. The results suggest “either that the stimulants may have seeped through the wrap of the packets, or that the subject had been abusing the drugs.”

Recent surveys have shown that the incidence of body packers is steadily increasing in numerous countries. Consequently, scientists are now faced with the challenge of detecting how the internal concealment of drugs affects health, particularly in terms of substance concentrations in important bodily fluids. In order to do this, scientists only use efficient, industry-standard gas chromatography systems. For inquiries on a high-quality gas chromatography system for your facility, fill out the form at the left.

A team of UK scientists at the Defence Science and Technology Laboratory, Porton Down, and University of Central Lancanshire, has recently developed a novel method of detecting the nerve agent “VX” and its hydrolysis products using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The study was published in the scientific journal “Analytical Methods” (Issue 10, 2012), and has been found to have significant implications on analyzing evidence of chemical weapon use and manufacture.

The nerve agent VX is an extremely toxic acetylcholinesterase inhibitor—classified by the United Nations as a “weapon of mass destruction.” Being one of the most lethal chemical warfare agents known to man, VX has been banned by the Chemical Weapons Convention in 1993. However, despite numerous laws against the production, use, and stockpiling of this dangerous nerve agent, the inhibitor somehow still finds its way into the possession of cults, terror groups, and states parties.

Determining when VX has been used proves to be a difficult process, as the chemical can be absorbed by soil. VX can also seep into groundwater, making it hard to recover for examination. To counter this, Matthew Baker, Matthew Gravett, and their team of researchers showed the effectiveness of plants such as mustard to take up VX and its breakdown products from contaminated soil. In their research, they were able to localize VX compounds in mustard and obtain them via ethanol extraction. These extracts were then analyzed by means of gas chromatography (GC) and liquid chromatography-mass spectrometry (LC-MS).

Analytes obtained were discovered to remain in the plants for at least 28 days (much longer than if they were left in soil), allowing ample amount of time for analysis and detection. According to Baker, this study shows the possibility of efficiently detecting VX by simply collecting local flora and extracting them.

In order to further measure the potential of plants as efficient VX detectors, the researchers are now planning to analyze VX compounds in different soils and extend the test to longer times. To match the accuracy of their earlier research, this investigation requires the use of high-quality gas chromatography systems. For inquiries on top-grade GC systems, simply fill out the form at the left.

An international group of scientists recently conducted a study using gas chromatography (GC) to determine the role of olfaction in the feeding behavior of Anopheles gambiae, one of the most active and efficient malaria vectors known to date.

As far as sugar feeding is concerned, earlier studies have shown that cases of discriminative plant feeding do occur in An. gambiae. However, very few have explored the principles behind the species’ attraction to certain plants.

Through a dual choice olfactometer, the researchers examined odor discrimination by the mosquito species to suspected host plants. Three plant species were used in the study: the Santa Maria Feverfew/Whitetop Weed (Parthenium hysterophorus), the Spanish Needle (Bidens pilosa), and the Castor Oil Plant (Ricinus communis).

Using gas chromatography-mass spectrometry (GC-MS), the researchers analyzed the trimethylsilyl derivatives of the three plant species to determine the sugar content of each. Volatile substances from intact plants were also analyzed using GC-electroantennographic detection (GC-EAD) and GC-MS to detect electrophysiologically-active components. They also used the active compounds and blends of the compounds to test the preferences of the female mosquitoes, the malaria vectors.

The researchers discovered that sugar contents were similar in the Santa Maria Feverfew Weed and the Spanish Needle, while the Castor Oil Plant contained a richer amount. Odors released by the Santa Maria Feverfew Weed were found to be the most attractive, with those from the Spanish Needle being the least attractive to females. Results also showed that one of the active compound blends was more attractive to the females than the compound from the most preferred plant, the Santa Maria Feverfew Weed.

The study revealed that the malaria vector Anopheles gambiae uses specific odors to locate host plants for nectar feeding. Findings also show that the species uses both quantitative and qualitative volatile composition to distinguish host plants. The researchers concluded that changing the concentrations of EAD-active components in a blend could lead to the development of plant-based lures for the species and in effect, help in the management of malaria vectors.

Controlling the spread of parasite-related diseases such as malaria remains to be top priority in some areas of the world. In the search to develop effective solutions to mitigate these prevalent diseases, scientists only use reliable and industry-standard gas chromatographs. For any inquiries on GC systems, feel free to fill out the form at the left.

Scientists from the Agricultural Research Service (ARS) of the US Department of Agriculture are working on how to save avocado trees from the threat of fungal infection caused by the redbay ambrosia beetle. Led by Paul Kendra, the team used gas chromatography – mass spectroscopy to determine the volatile compounds (VOCs) released by the trees that attract the beetle, leading them to infect the trees.

As the disease caused by the fungus Raffaelea lauricola reached the trees in the Carolinas, Florida and Mississippi, scientists in ARS are searching to minimize the spread of the disease to major avocado production areas including California and Mexico. The ARS team is currently seeking chemical attractants that they can use when developing beetle traps.

One of the studies involved “choice experiment”. The researchers placed lychee, another highly attractive tree to the redbay beetle, and avocado woods on opposite sides of a plastic bin and put the beetle in the middle to see which wood the insect prefers. The VOCs released by the woods were analyzed through gas chromatography – mass spectroscopy (GC-MS). Published in the Journal of Chemical Ecology, the results showed that of 29 compounds detected, three of these compounds attract the beetles and are abundant in lychee wood.

In a different ARS study, the team looked into the compounds emitted by seven tree species that lure the beetle. The researchers collected freshly cut tree samples from a variety of lychee tree, redbay, avocado and four species of a laurel tree. They placed the samples in glass chambers with purified air and special filters that collect the released gases. These compounds were then analyzed with GC-MS which showed that a “generalized bouquet” of 11 compounds was released by the laurel trees, and four of which are from lychee. The team discovered that the compounds emitted were the same with the ones in the previous study published in the Journal of Chemical Ecology.

The ARS team is currently focusing on these compounds to determine attractants for the beetle.

The identification of compounds emitted by organisms of an ecosystem helps define the behavior and characteristics of specific species, including beetles and trees. To do so, scientists and researchers use high-quality gas chromatography systems to accurately identify these compounds. The findings help them better understand the relationships between species, and the conservation of the species. For inquiries on top-grade GC systems for your facility, fill out the form at the left.

Researchers used gas chromatography and mass spectrometry in creating futuristic soundscapes for air pollution. Aaron Reuben, researcher at Yale Center for Environment Law and Policy, and Gabriel Isaacman, doctoral student at the University of California-Berkeley, conducted a study on identifying air quality through sonic representations. The article was published in “The Atlantic”, an American magazine featuring articles about political science, cultural trends and technology.

The team explained that research groups at UC Berkeley and UNC Chapel helped them collect samples from across the state to differentiate the quality of air in parts of California, including Caldecott Tunnel in Oakland, Bakersfield, Pasadena and Sierra Mountains. Reuben and Isaacman, together with the UC Berkeley research group conducted data analysis to determine the properties of each air sample.

Using gas chromatography, researchers separated the compounds that make up these samples and applied mass spectrometry to determine these compounds. Tones were then assigned to each. “Some compounds end up sounding clear and distinct, while others blur together into unresolvable chords. The result is a qualitative, sensory experience of hard, digital data. You can actually hear the difference between the toxic air of a truck tunnel (clogged with diesel hydrocarbons and carcinogenic particulate matter) and the fragrant air of the High Sierras,” the lead researchers explained. Significant differences among the sounds emitted by the air collected from the specific California areas also showed similarities in sound patterns.

Researchers pointed out that growing human emission greatly affects the air quality in these areas, leading to inaccurate pollution models. “[T]o better understand and regulate our changing climate, the consequences of mixing those bubbly, natural tones with that droning, fossil-fuel chord need to be better studied,” the pair concluded.

Current air quality in the earth’s atmosphere is a growing concern among scientists across the globe. To address this problem, air pollution scientists conduct studies to understand and improve air quality. For accurately identified compounds, researchers and scientists use top-of-the-line gas chromatograph. For inquiries on a high-quality gas chromatography system for your facility, fill out the form at the left.

An international team of researchers from Israel and Colorado conducted a study to develop a non-invasive diagnostic method of lung cancer. The procedure involves collecting exhaled breath samples from patients. Having major implications on lung cancer research, this study has recently been published in the Journal of Thoracic Oncology.

For this analysis, gas chromatography – mass spectrometry (GC-MS) was combined with solid-phase microextraction along with a chemical nanoarray method. Through these methods, researchers were able to discover benign and pulmonary nodules from the exhaled volatile organic compounds of 72 patients.

Patients were then subjected to final diagnosis via bronchoscopy, wedge resection and/or lobectomy, depending on the appropriate procedure. By the end of the 24-month period, 53 patients were found to have malignant pulmonary nodules, while the rest had benign ones. The chemical nanoarray method also made a distinction between adenocarcinoma and squamous cell carcinoma, as well as between early stage and advanced disease.

According to the authors, results from these non-invasive GC-MS and chemical nanoarray methods can help reduce unnecessary investigation and invasive procedures, as well as procedure-related morbidity and costs. They also added that the results “could facilitate faster therapeutic intervention, replacing time-consuming clinical follow-up that would eventually lead to the same intervention.”

Conducting further studies to validate the efficiency of this non-invasive diagnostic approach will require the use of high-quality gas chromatography systems. For inquiries on GC systems, simply fill out the form at the left.

Using gas chromatography (GC), scientists from Woods Hole Oceanographic Institute (WHOI) and King Abdullah University of Science and Technology recently conducted a quantitative study on the habitat connectivity of a tropical fish. The study aimed to quantify the movements of the fish within the seascape in relation to population preservation of the species.

“The rationale for this study was to determine the relative importance of different nursery habitats to reef fishes that spend their adult lives on coral reefs but may spend at least part of their juvenile residency elsewhere,” Simon Thorrold, a biologist in WHOI explained. WHOI biologist and lead author Kelton McMahon also added that the quantitative method they have developed “identifies essential nursery habitat, and allows reconstruction of migration within the seascape.”

To recreate the migration pattern and understand the behavior of the fish, the two WHOI scientists with Michael Berumen of King Abdullah University of Science and Technology in Saudi Arabia, first created an isoscape, a map showing the unique isotope signatures of habitats. Five specific habitats in the Red Sea were part of the isoscape, including coastal wetlands, coastal reefs near the shoreline, reefs on the continental shelf (down to 60 meters), patch reefs around offshore islands, and oceanic reefs in deep open water. The isotopic signatures would be based on the fish otolith or ear bone, which constantly records fish activity including the different food webs they have been part of. The food webs, in turn, point to the environment the fish have gone through.

The scientists then collected full-grown Ehrenberg’s snappers (Lutjanus ehrenbergii), a widely available commercial fish found in tropical and subtropical waters. The team used GC to assess the compounds in the otoliths of each individual fish, tracing back to its juvenile stage. They were able to match the signatures to the isoscape, providing them accurate data of where each fish lived in the map as a juvenile. Their findings revealed that coastal wetlands are not the only nursery habitat for the species, as some juvenile fish were found to have settled on the reefs. The continental island was also proven to have been an important habitat.

Results showed that seascape configuration is an important but unacknowledged factor in determining connectivity among the habitats. “We found that coral reef fish made remarkable long-distance migrations from coastal wetlands across deep open water – long considered a hard migration barrier for coral reef fish – to offshore reefs… [M]igration capability was far greater than we originally appreciated. It underscores the potential of significant connectivity within a large and complex tropical seascape,” McMahon said. He added that the protection of the migration corridors that connect the different habitats is as important as the preservation of the coral reefs the adult fish inhabit.

The study is available in the recent issue of the Proceedings of the National Academy of Sciences.

The researchers aim to study other significant coral reefs and tropical seascapes in other parts of the globe to see if these patterns are visible in those areas.

Through chemical analyses like gas chromatography, scientists have been provided with results leading to remarkable discoveries in understanding the behavior of animals. The information from these studies aid in the preservation of different species. To ensure accuracy is achieved during the study, scientists and researchers only use a top-quality gas chromatography system. For any inquiries on high-quality GC systems, feel free to fill out the form at the left.

Photo courtesy of Woods Hole Oceanographic Institute.

Scientists have developed a gas chromatographic method that determines the level of Chlorpyrifos (CP) and its metabolite Chlorpyrifos-oxon (CPO) in wine. Chlorpyrifos, a widely-used insectide in the agricultural industry, has harmful health effects including developmental and autoimmune disorders. This new method is reported to be the first validated technique to quantify CP and CPO levels in wine samples.

Using pulsed splitless technique coupled with gas chromatography, scientists from Ege University in Turkey quantified the amounts of CP and CPO in wine samples. To separate the components in the samples, they used a quick, easy and cheap sample preparation method (QuEChERS) followed by dispersive solid phase extraction. Findings showed CP content of 2.05 ± 0.15 ng/ml with relative standard deviation (RSD) of 7.6% and CPO amount of 4.99 ± 0.15 ng/ml with RSD of 3.0%.

The team initiated the study to create a monitoring procedure of pesticides and their metabolites in food quality. Entitled “Development of a gas chromatographic method for the determination of Chlorpyrifos and metabolite Chlorpyrifos-oxon in wine matrix”, the study will be available in Elsevier’s Journal of Chromatography B September issue.

As part of food safety measures, experts in the industry continue to develop and improve the methods used to monitor any dangerous and potentially harmful substances in food products including wine and similar alcoholic beverages. Scientists only use top-quality gas chromatographs in their research to ensure the accuracy of their data and the validity of their subsequent conclusions. For any inquiries on high-quality gas chromatography systems, feel free to fill out the form at the left.

Scientists conducted a gas chromatography test on the artificial scents used to train cadaver dogs. A team of researchers from the University of Ontario Institute of Technology, Queen’s University in Canada and the University of Leige in Belgium checked the accuracy of the kits that law enforcement units use for cadaver dog training. The paper is published online at Elsevier’s Journal of Chromatography A and will be available in print in its September issue.

Cadaver dogs are law enforcement canines trained to follow and search the scent of decomposing human remains after a disaster. These dogs are trained with a variety of materials and artificial scents. Since the training kit used has not been evaluated yet, the scientists initiated a test on the accuracy of two pseudo scents available commercially.

Using comprehensive two-dimensional gas chromatography – time of flight spectroscopy (GC x GC – TOFMS), the team found out that their samples showed a simpler composition compared to the volatile organic compounds (VOCs) found in a corpse. The technique enabled the researchers “to discriminate less intense peaks from large overloaded peaks”. According to the team, the compounds identified in the compound “do not appear to be representative of decomposition odor”. They further suggested that a follow-through olfaction research on cadaver scent should be conducted to improve existing canine training aids.

Gas chromatography has aided experts in the development of forensic techniques including kits for cadaver dog training. Scientists and researchers only use top-quality GC systems to ensure accuracy is met. For inquiries on gas chromatography systems, please feel free to fill out the form at the left.

(Photo by Tom Pennington: Chance, a cadaver dog, searches for remains in the wake of a tornado that hit Tuscaloosa, Alabama on April 2011.)