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PubMed2003

[Blood pressure volatility--a new parameter for determining blood pressure variability in type-1 diabetes mellitus].

INTRODUCTION: In diabetes the heart rate variability is decreased because of the autonomic neuropathy and parallel with this phenomenon the overnight blood pressure fall is lost. Presumably this change in the hemodynamic parameters is connected with the fact that the cardiovascular complications in type 1 diabetic patients are 2-4 times more frequent than in healthy patients. The volatility, as a new factor, is the dispersion of the proportion of the blood pressure values following each other. It exactly reflects the 24-hour blood pressure fluctuation, while the dipper/non-dipper determination differentiates only between the daytime and night-time average blood pressure values. The volatility follows the changes of the measured values in accordance to the frequency of the measurements during the whole day. AIM: Our aim was to compare the blood pressure variability of type 1 diabetic patients (DM) and healthy controls (C). PATIENTS AND METHODS: The authors examined 43 diabetic patients from our outpatient clinic and 45 healthy people. The blood pressures were measured with Meditech ABPM 02 monitor on workdays. The measurements started in the mornings. The frequency of the measurements was 20 minutes during the day and 50 minutes at night-time. The authors took the history of all the patients and detailed laboratory results. The patients also had ophthalmology examination, ECG and echocardiography tests. RESULTS: During the Ambulatory Blood Pressure Monitoring we found that the systolic volatility of blood pressure values was significantly lower in DM compared to C patients. Systolic volatility: 0.133 +/- 0.011 vs. 0.175 +/- 0.014 p < 0.026. Comparing only the normotonic C and DM group systolic volatility of blood pressure values were significantly lower in DM. Systolic volatility: 0.128 +/- 0.016 vs. 0.177 +/- 0.021 p < 0.036. CONCLUSION: It is an important new finding that in type 1 diabetic patient the volatility--a new parameter for determining blood pressure variability--is lower than in the healthy control group. At normotension state other parameters describing the blood pressure variability (like diurnal index or standard deviation) could not show this change.

Adult↗
PubMedDate not supplied

Comparison of volatile acid number test with enzymatic acetic acid assay for assessment of seafood quality.

Volatile acid number, an official AOAC method for assessing seafood quality, was compared with an enzymatic method for measuring acetic acid. Thirty-eight samples of fresh fish and 23 samples of canned fish were evaluated. The data showed high positive correlations between volatile acid number and enzymatic acetic acid methods; the correlation coefficient was 0.98 for fresh fish and 0.95 for canned fish. Positive correlation coefficients of 0.93 and 0.96 were also associated with samples of fish divided into 2 groups on the basis of acceptable or unacceptable quality, respectively. There was no significant difference between the means for the volatile acid number and enzymatic acetic acid procedures at the 5% level of significance. Decomposition studies on cod and mackerel, representing a lean and fatty fish, respectively, were monitored over 9 days by using the following analyses: volatile acid number, acetic acid, total volatile bases, and thiobarbituric acid. Results of the decomposition studies showed that enzymatic acetic acid levels closely paralleled volatile acid number values in both lean and fatty fish. Total volatile bases was a reliable supplemental measure for evaluating lean seafood quality, whereas thiobarbituric acid was more appropriate for further assessment of fatty fish quality.

Acetates↗
PubMed1988

Prolongation of the QT interval by volatile anesthetics in chronically instrumented dogs.

The influence of volatile anesthetics on ventricular repolarization in vivo (QT interval) has not been studied in a systematic fashion. The purpose of this investigation was to characterize the electrocardiographic and hemodynamic actions of the volatile anesthetics halothane, isoflurane, and enflurane in chronically instrumented dogs. Because autonomic nervous system tone may influence ECG findings, experiments were completed with and without concomitant pharmacologic autonomic nervous system blockade. In six groups comprising 50 experiments with 21 instrumented dogs, anesthesia was mask-induced with nitrous oxide, oxygen, and one of the volatile anesthetics and maintained with the volatile anesthetic in 100% oxygen for 2 hours. Changes in the ECG and in hemodynamics were compared to the conscious state. In the absence of autonomic nervous system blockade, halothane and isoflurane significantly prolonged the QT interval (0.24 +/- 0.01 to 0.30 +/- 0.01 second and 0.22 +/- 0.01 to 0.28 +/- 0.01 second, respectively), whereas enflurane produced no change in ventricular repolarization (0.24 +/- 0.01 to 0.26 +/- 0.01 second). All of the volatile anesthetics increased the QT interval corrected for changes in basal heart rate (QTc), and all agents decreased intravascular pressure and dP/dt. Following autonomic nervous system blockade, halothane, isoflurane, and enflurane significantly increased the QT interval and QTc. The results demonstrate that ventricular repolarization is directly altered by the volatile anesthetics independent of changes in autonomic nervous tone. Whether or not such effects are additive with other congenital or acquired forms of QTc prolongation has yet to be examined. The present results indicate that caution should be used during the administration of volatile anesthetics to patients with abnormalities of the QT interval.

Animals↗
PubMed2004

Analysis of volatiles in porcine liver pâtés with added sage and rosemary essential oils by using SPME-GC-MS.

The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils) and one synthetic (BHT) on the generation of volatile compounds in liver pâtés from Iberian and white pigs was analyzed using SPME-GC-MS. Lipid-derived volatiles such as aldehydes [hexanal, octanal, nonanal, hept-(Z)-4-enal, oct-(E)-2-enal, non-(Z)-2-enal, dec-(E)-2-enal, deca-(E,Z)-2,4-dienal] and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace of porcine liver pâtés. Pâtés from different pig breeds presented different volatiles profiles due to their different oxidation susceptibilities as a probable result of their fatty acid profiles and vitamin E content. Regardless of the origin of the pâtés, the addition of BHT successfully reduced the amount of volatiles derived from PUFA oxidation. Added essential oils showed a different effect on the generation of volatiles whether they were added in pâtés from Iberian or white pigs because they inhibited lipid oxidation in the former and enhanced oxidative instability in the latter. SPME successfully allowed the isolation and analysis of 41 volatile terpenes from pâtés with added sage and rosemary essential oils including alpha-pinene, beta-myrcene, 1-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of liver pâtés.

Animals↗
PubMed2002

Comparison of long-chain alcohols and other volatile compounds emitted from food-borne and related Gram positive and Gram negative bacteria.

Numerous reports have been published on the antimicrobial activity of synthetic volatile long chain alcohols, such as 1-decanol and 1-dodecanol, against bacteria and fungi. The objective of the present study was to survey microorganisms for emission patterns of naturally occurring long chain alcohols and other volatile components to determine if these compounds are associated with certain groups of bacteria. Cultures were grown in trypticase soy broth overnight and volatile compounds were trapped on a porous polymer and identified by mass spectrometry. Subsequently, volatile compounds were collected from 26 strains of food associated bacteria using solid-phase microextraction and analyzed by gas chromatography. Alcohols comprising 1-octanol, 1-decanol, and 1-dodecanol occurred as products from enteric Gram negative bacteria, which included Citrobacter, Enterobacter, Klebsiella, Salmonella, and Shigella. However, the long chain alcohols were not detected as products from the nonenteric Gram negative species studied which included Acinetobacter, Pseudomonas, and Shewanella. Among Gram positive bacteria, including Bacillus, Enterococcus, Lactococcus, Leuconostoc, Listeria, Staphylococcus, and Streptococcus, the only long chain alcohol detected was 1-decanol and, if present, it occurred in relatively small amounts. Other classes of compounds emitted by bacteria included methylketones and sulfides. The methylketones were found as products from Gram positive and Gram negative bacteria, whereas the sulfides were closely associated with Gram positive bacteria. In summary, the emission patterns of volatile compounds from bacteria showed many trends including the association of long chain alcohols with enteric Gram negative bacteria. The results provide a basis for future in vivo studies to determine if volatile compounds such as natural long chain alcohols function in the ecology of food-borne Gram negative bacterial pathogens.

Alcohols↗
PubMed1975

Volatility of fungicidal mercury compounds on wheat seeds.

The volatility of two fungicidal seed dressings, Panogen 15 B liquid and Panogen PX powder, containing methyl mercuric dicyandiamide in equivalent amounts at the dosage used, was compared with that of triple distilled mercury. Tests were made in the absence and presence of cleaned Manitou wheat of 12.0% and 17.1% moisture content. The Panogen formulations were compared at the recommended and twice the recommended rate at different dosages, storage periods and storage temperatures. The Hg content of air samples was determined by the Corte-Monkman method, capable of determining 0.4 ng of Hg, which in a 1-L air sample is equivalent to 0.049 ppb (v/v). The volatility of the interstitial air expressed as mug of Hg vapor/m3 air depended on temperature, wheat moisture content and storage duration and ranged from 150 to 2,240 for metallic Hg, 21 to 350 for Panogen 15 B, and 31 to 380 for PX. In the absence of wheat the volatility of 15 B was greatest (395) at -17.5 degees C and least (75) at 4.5 degrees C, but increased rapidly thereafter with increased temperature. Volatility of metallic Hg after application to wheat of 12.0% and 17.1% moisture content was not significantly reduced after four days storage, but that of Panogen 15 B and PX was reduced considerably, particularly at the higher moisture level. Thus, volatility of mercurial seed dressings cannot be predicted from Hg content alone. Reduction of volatility through possible irreversible chemical bonding of Hg with seed components is suggested for more detailed investigation.

Air↗
PubMed1999

Accelerated volatilization rates of selenium from different soils.

Selenium (Se), an element found naturally in a variety of soils, can accumulate in drainage water of lands under intensive irrigation, even reaching levels that are toxic to mammals and birds. Volatilization of Se by soil microorganisms into dimethylselenide (DMSe) can be enhanced by certain soil amendments and, thus, be used as a soil remediation process. In an 8-wk laboratory study, five soils from California and one from Germany were spiked with 75SeO3(2-) (22.3 mg/kg Se). Two amino acids (DL-homocysteine and L-methionine), a carbohydrate (pectin), and a protein (zein) were tested as soil amendments. Gaseous 75Se emissions were trapped with activated carbon and measured in a gamma counter. Depending on soil type, the cumulative volatilization from the control flasks varied between 1.2% and 9.0% of applied 75Se. Both zein and L-methionine strongly increased volatilization (max. 43% of 75Se applied), whereas DL-homocysteine had a much smaller stimulating effect. Pectin showed a moderate effect, but enhanced Se volatilization rates were sustained much longer when compared to the zein amendment. Volatilization rates of Se followed a simple first-order reaction. Gaseous Se emission in the soils treated with L-methionine yielded an S-shaped curve, which fit a growth-modified first-order rate model. Although zein and L-methionine were the most favorable treatments enhancing Se volatilization, all six soils responded differently to the soil amendments.

Selenium↗
PubMed2006

Simultaneous control of apparent extract and volatile compounds concentrations in low-malt beer fermentation.

Volatile compounds cause undesirable flavor when their concentrations exceed threshold values in beer fermentation. The objective of this study is to develop a system for controlling apparent extract concentration, which indicates the fermentation degree and which should be decreased below a targeted value at a fixed time under a constraint of tolerable amounts of volatile compounds. In beer fermentation, even though the production of volatile compounds is suppressed by maintaining a low fermentation temperature, a low temperature causes a delay in the control of apparent extract concentration. Volatile compound concentration was estimated on-line, and the simulation of apparent extract consumption and volatile compound production was performed. To formulate various beer tastes and conserve energy for attemperation, optimal temperature profiles were determined using a genetic algorithm (GA). The developed feedback control of the brewing temperature profile was successfully applied, and apparent extract and volatile compound concentrations at a fixed time reached their target concentrations. Additionally, the control technique developed in this study enables us to brew a wide variety of beers with different tastes.

Acids↗
PubMed2004

Rhythmic emission of floral volatiles from Rosa damascena semperflorens cv. 'Quatre Saisons'.

The control of rhythmic emission of floral volatiles emitted from Rosa damascena semperflorens cv. 'Quatre Saisons' throughout floral development under various light regimes was studied. 2-Phenylethanol was the major volatile emitted in addition to monoterpenols, oxidised monoterpenols, monoterpenes and aromatic compounds. All detected volatiles were emitted rhythmically, with maximum peaks coinciding 8-10 h into a 12-h photoperiod. For some compounds a secondary, nocturnal peak was apparent. The primary and secondary maxima both occurred at approximately 24-h intervals. Rhythms appeared to be regulated endogenously: rhythmic emission continued upon exposure to continuous light or continuous darkness, and a phase shift in emission was induced upon inversion of the photoperiod. Additionally, emission continued after flower excision. A similar profile of free volatiles was stored within the floral tissue, together with glycosidic forms of 2-phenylethanol (>99% beta-D-glucoside), benzyl alcohol, citronellol and geraniol. Regression analysis indicated a significant decrease in glycosylated 2-phenylethanol through the photoperiod. These results suggest that glycosylated volatiles stored within petals may be a source of rhythmically emitted volatiles.

Alcohols↗
PubMed2005

Phytohormones mediate volatile emissions during the interaction of compatible and incompatible pathogens: the role of ethylene in Pseudomonas syringae infected tobacco.

Interactions between the phytohormones ethylene, salicylic acid (SA), and jasmonic acid (JA) are thought to regulate the specificity of induced plant defenses against microbial pathogens and herbivores. However, the nature of these interactions leading to induced plant volatile emissions during pathogen infection is unclear. We previously demonstrated that a complex volatile blend including (E)-beta-ocimene, methyl salicylate (MeSA), and numerous sesquiterpenes was released by tobacco plants, Nicotiana tabacum K326, infected with an avirulent/incompatible strain of Pseudomonas syringae pv. tomato (Pst DC3000). In contrast, a volatile blend, mainly consisting of MeSA and two unidentified sesquiterpenes, was released by plants infected with P. syringae pv. tabaci (Pstb) in a virulent/compatible interaction. In this study, we examined the interaction of multiple pathogen stresses, phytohormone signaling, and induced volatile emissions in tobacco. Combined pathogen infection involved the inoculation of one leaf with Pst DC 3000 and of a second leaf, from the same plant, with Pstb. Combined infection reduced emissions of ocimene and MeSA compared to plants infected with Pst DC 3000 alone, but with no significant changes in total sesquiterpene emissions. In the compatible interaction, Pstb elicited a large ethylene burst with a peak emission occurring 3 days after inoculation. In contrast, the incompatible interaction involving Pst DC3000 displayed no such ethylene induction. Pstb-induced ethylene production was not significantly altered by Pst DC3000 in the combined infection. We postulated that Pstb-induced ethylene production may play a regulatory role in altering the typical volatile emission in tobacco in response to Pst DC3000 infection. To clarify the role of ethylene, we dynamically applied ethylene to the headspace of tobacco plants following infection with Pst DC3000. Consistent with Pstb-induced ethylene, exogenous ethylene reduced both ocimene and MeSA emissions, and selectively altered the ratios and amounts of induced sesquiterpene emissions. Our findings suggest that ethylene can regulate the magnitude and blend of induced volatile emissions during pathogen infection.

Cyclopentanes↗
PubMed2005

Variation in plant volatiles and attraction of the parasitoid Diadegma semiclausum (Hellén).

Differences in allelochemistry of plants may influence their ability to attract parasitoids. We studied responses of Diadegma semiclausum (Hellén), a parasitoid of the diamondback moth (Plutella xylostella L.), to inter- and intraspecific variation in odor blends of crucifers and a non-crucifer species. Uninfested Brussels sprout (Brassica oleracea L. gemmifera), white mustard (Sinapis alba L.), a feral Brassica oleracea, and malting barley (Hordeum vulgare L.) were compared for their attractivity to D. semiclausum in a Y-tube bioassay. Odors from all plants were more attractive to the parasitoid than clean air. However, tested against each other, parasitoids preferred the volatile blend from the three cruciferous species over that of malting barley. Wasps also discriminated between uninfested crucifers: mustard was as attractive as feral B. oleracea, and both were more attractive than Brussels sprout. Attractivity of uninfested plants was compared with that of plants infested by larvae of the host P. xylostella. Host-infested mustard and Brussels sprout were more attractive than uninfested conspecifics. Interestingly, the volatile blends of uninfested white mustard and infested Brussels sprout were equally attractive. We also compared the volatile composition of different plant sources by collecting headspace samples and analysing them with GC-MS. Similarities of volatile profiles were determined by hierarchic clustering and non-metric scaling based on the Horn-index. Due to the absence of several compounds in its blend, the volatile profile of barley showed dissimilarities from blends of crucifers. The odor profile of white mustard was distinctly different from the two Brassicaceae. Feral Brassica oleracea odor profile was different from infested Brussels sprout, but showed overlap with uninfested Brussels sprout. Odor blends from infested and uninfested Brussels sprout were similar, and mainly quantitative differences were found. D. semiclausum appears to discriminate based on subtle differences in volatile composition of odor blends from infested and uninfested plants.

Animals↗
PubMed2006

Effects of genetic modification on herbivore-induced volatiles from maize.

Large-scale implementation of transgenic crop varieties raises concerns about possible nontarget effects on other organisms. This study examines the effects of genetic modification on plant volatile production and its potential impact on arthropod population dynamics. We compared herbivore-induced volatile emissions from Bacillus thuringiensis Berliner (Bt) maize plants to those from a nontransformed isoline following exposure to various types of leaf damage. When equal numbers of Helicoverpa zea Boddie (Lepidoptera: Noctuidae) larvae fed on Bt and non-Bt maize, volatile emissions were significantly lower in the transgenic plants, which also exhibited less leaf damage. When damage levels were controlled by adding more larvae to Bt plants, the plants' volatile emissions increased but displayed significant differences from those of nontransgenic plants. Significantly higher amounts of linalool, beta-myrcene, and geranyl acetate were released from transgenic maize than from non-Bt plants. Manipulating the duration of feeding by individual larvae to produce similar damage patterns resulted in similar volatile profiles for Bt and non-Bt plants. Controlling damage levels more precisely by mechanically wounding leaves and applying larval regurgitant likewise resulted in similar emission patterns for Bt and non-Bt maize. Overall, changes in the herbivore-induced volatile profiles of Bt maize appeared to be a consequence of altered larval feeding behavior rather than of changes in biochemical plant defense pathways. The implications of these findings for understanding the impacts of plant-mediated cues on pest and natural enemy behavior in transgenic crop systems are discussed.

Animals↗
PubMed2006

Analysis of the volatiles emitted by whole flowers and isolated flower organs of the carob tree using HS-SPME-GC/MS.

The volatiles emitted by fresh whole flowers and isolated flower organs of male, female, and hermaphrodite carob trees (Ceratonia siliqua L.; Leguminosae) were analyzed by headspace solid-phase microextraction followed by capillary gas chromatography and mass spectrometry. The headspace of carob flowers is mainly constituted of high amounts of monoterpenes and sesquiterpenes, and more than 25 compounds were identified. The gender and cultivar affected both the qualitative profile and the relative abundances of the volatiles of whole flowers and isolated floral organs. Linalool and its derivatives (cis-linalool furan oxide, 2,2,6-trimethyl-3-keto-6-vinyltetrahydropyran, cis-linalool pyran oxide, and trans-linalool furan oxide), alpha-pinene, and alpha-farnesene were the dominant volatiles. Female flowers had a higher diversity of volatile compounds than males and hermaphrodites, but a lower abundance of the major ones. Similarly, the floral scent of female flowers of cv. Mulata had a higher content of volatiles but a lower abundance of the major ones, when compared to cv. Galhosa. In each of the three gender types of flowers, the nectary disks seemed to be the major source of volatiles.

Fabaceae↗
PubMed2006

Production and predator-induced release of volatile chemicals by the plant bug Lygus hesperus.

Both sexes of adult western tarnished plant bug, Lygus hesperus Knight (Heteroptera: Miridae), released three volatile chemicals in relatively large amounts when attacked by ants (Pogonomyrmex rugosus and Solenopsis xyloni) or when grabbed by forceps, as determined by solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The relative amounts of the volatile compounds, hexyl butyrate, (E)-4-oxo-2-hexenal, and (E)-2-hexenyl butyrate, absorbed by SPME as a percentage of the largest were 100%, 44%, and 4%, respectively, from females, and 83%, 37%, and 3% from males. Both ant species were repelled by the defensive discharges (confirmed by SPME) when the ants attacked L. hesperus adults. Sexually mature L. hesperus were individually extracted in pentane to quantify the mean amounts of hexyl butyrate (14.9 microg/female; 10.3 microg/male), (E)-4-oxo-2-hexenal (2.7 microg/female; 3.1 microg/male), and (E)-2-hexenyl butyrate (1.2 microg/female; 0.6 microg/male). (E)-4-Oxo-2-hexenal was unstable in solvent when in contact with a macerated adult, but relatively stable when the solution was decanted within minutes. The production of the three major volatile components began soon after the emergence of the adult and amounts increased for about 5-10 d with little or no increase thereafter. Minor additional constituents were cross-correlated in many cases with the three major ones. A cost of defensive secretion is suggested for females but not for males, because heavier females produced more volatile compounds than lighter females. The initial discharge percentage, defined as the proportion of volatile compounds initially present that is discharged to defend against predation was estimated at about 50% in males and 70% in females. Newly eclosed adults did not produce volatile chemicals until 2 d after molting.

Aging↗
PubMed2006

Fungal infection reduces herbivore-induced plant volatiles of maize but does not affect naïve parasitoids.

Plants attacked by insects release volatile compounds that attract the herbivores' natural enemies. This so-called indirect defense is plastic and may be affected by an array of biotic and abiotic factors. We investigated the effect of fungal infection as a biotic stress agent on the emission of herbivore-induced volatiles and the possible consequences for the attraction of two parasitoid species. Maize seedlings that were simultaneously attacked by the fungus Setosphaeria turcica and larvae of Spodoptera littoralis emitted a blend of volatiles that was qualitatively similar to the blend emitted by maize that was damaged by only the herbivore, but there was a clear quantitative difference. When simultaneously challenged by fungus and herbivore, the maize plants emitted in total 47% less of the volatiles. Emissions of green leaf volatiles were unaffected. In a six-arm olfactometer, the parasitoids Cotesia marginiventris and Microplitis rufiventris responded equally well to odors of herbivore-damaged and fungus- and herbivore-damaged maize plants. Healthy and fungus-infected plants were not attractive. An additional experiment showed that the performance of S. littoralis caterpillars was not affected by the presence of the pathogen, nor was there an effect on larvae of M. rufiventris developing inside the caterpillars. Our results confirm previous indications that naïve wasps may respond primarily to the green leaf volatiles.

Animals↗
PubMed1984

Selenite biotransformation to volatile metabolites in an isolated hepatocyte model system.

The biotransformation of selenite to dimethylselenide was studied in an oxygenated hepatocyte model system. The concentrations of selenite used were 20-100 microM. A lag period of one hour or more, during which no net formation of selenide could be detected characterized the system. The maximal rate of volatilization was recorded during the second hour and was 0.13 nmoles/10(6) cells/min with 50 microM selenite. The rate then declined and volatilization eventually ceased. Two-thirds of the added amount of Se was lost within 4 hr. Oxidation of glutathione (GSH) by cumene hydroperoxide delayed volatilization. An inhibitor of gluconeogenesis, p-tert-butylbenzoic acid (3 microM) prevented volatilization. There were indications that GSSG reductase dependent metabolism was the only major metabolic pathway in hepatocytes under the conditions studied. During the lag period Se accumulated in cells, but was subsequently partially released during volatilization. The accumulation of Se was paralleled by an increase in oxygen uptake. The above mentioned inhibitors of volatilization prolonged the phase of accumulation. With 50 microM selenite the rate of accumulation was 0.06 nmoles/10(6) cells/min and maximally 30-35% of the added dose was retained in the cells. The results are compatible with the assumption that Se mainly accumulated as Se-glutathione complexes. The possibility that such complexes autooxidized and entered futile redox cycles during the lag period is discussed.

Animals↗
PubMed2004

Comparison of different extraction methods: steam distillation, simultaneous distillation and extraction and headspace co-distillation, used for the analysis of the volatile components in aged flue-cured tobacco leaves.

Steam distillation (SD), simultaneous distillation and extraction (SDE) and headspace co-distillation (HCD) were compared here for their effectiveness in the extraction of volatile compounds from tobacco. The different grades of aged flue-cured tobacco leaves extracted by the three methods respectively were analyzed using GC-MS. Mass spectra or authentic compounds were used to identify around 408 components in various volatile fractions. On the one hand, the qualitative comparison showed that more compounds were detected in HCD extract (391 components) than in SDE extract (377 components), and the approximately quantitative analysis showed that the total amount of volatile components in SDE extract (445.48 microg/g) was much more than that in HCD extract (315.72 microg/g). But on the other hand, HCD was the most efficient for nearly all the highly volatile compounds among the three methods. As to low-volatile compounds such as lactones, long chain aldehydes, ketones, alcohols, and esters, more was detected in SDE extract than in HCD extract. The SD method (322 components, total amount 228.42 microg/g) was the lowest sensitive to all compounds except semi-volatile fatty acids among the three methods.

Gas Chromatography-Mass Spectrometry↗
PubMed2006

Measurement of trifluralin volatilization in the field: Relation to soil residue and effect of soil incorporation.

Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops. A field experiment (September, 2002), consisted in volatilization fluxes measurements during 6 days, covering the periods before and after soil incorporation carried out 24 h after trifluralin spraying on bare soil. Evolution of concentration in soil was measured during 101 days, together with soil physical and meteorological variables. Volatilization fluxes were very high immediately after application (1900 ng m(-2) s(-1)), decreased down to 100 ng m(-2) s(-1) in the following 24 h. Soil incorporation strongly abated trifluralin concentration in the air. 99% of the total volatilization losses recorded over the 6 days following application occurred before incorporation. Volatilization fluxes evidenced a diurnal cycle driven by environmental conditions. Soil trifluralin residues could still be quantified 101 days after application. Our results highlight the caution required when using soil degradation half-life values in the field for volatile compounds.

Air Pollutants↗