Smoke Samples Research Articles

Intercomparison of thermal-optical method with different temperature protocols: Implications from source samples and solvent extraction

Three temperature protocols with different peak inert mode temperature (Tpeak-inert) were compared based on source and ambient samples (both untreated and extracted using a mixture of hexane, methylene chloride, and acetone) collected in Beijing, China. The ratio of EC580 (elemental carbon measured by the protocol with a Tpeak-inert of 580 °C; similar hereinafter) to EC850 could be as high as 4.8 for biomass smoke samples whereas the ratio was about 1.0 for diesel and gasoline exhaust samples. The EC580 to EC850 ratio averaged 1.95 ± 0.89 and 1.13 ± 0.20 for the untreated and extracted ambient samples, whereas the EC580 to EC650 ratio of ambient samples was 1.22 ± 0.10 and 1.20 ± 0.12 before and after extraction. It was suggested that there are two competing mechanisms for the effects of Tpeak-inert on the EC results such that when Tpeak-inert is increased, one mechanism tends to decrease EC by increasing the amount of charring whereas the other tends to increase EC through promoting more charring to evolve before native EC. Results from this study showed that EC does not always decrease when increasing the peak inert mode temperature. Moreover, reducing the charring amount could improve the protocols agreement on EC measurements, whereas temperature protocol would not influence the EC results if no charring is formed. This study also demonstrated the benefits of allowing for the OC and EC split occurring in the inert mode when a high Tpeak-inert is used (e.g., 850 °C).

Une augmentation du périmètre abdominal

Mainstream and sidestream smoke samples from two types of cigarette standards (3R4F and 1R5F) were directly analyzed by a chemical ionization mass spectrometer (CIMS). A Walton smoke machine was used to ensure the cigarette is smoked in an acceptably reproducible manner among experiments. Gas-phase material was analyzed in real time and particles were collected on a Nichrome filament, and desorbed at 500° C for analysis immediately after collection was complete. Nicotine was observed to be the most prevalent compound in both phases, indicative of its well-known partitioning behavior. Gas-phase species present in significant amounts in the sidestream samples include benzene, toluene, isoprene, pyridine, 3-ethenylpyridine, xylene, naphthalene, isoquinoline, myosmine, and nicotyrine. Mainstream gas samples exhibited different signatures, dominated by acetaldehyde, acetone, pyrrole, pyrroline, pyrrolidine, and phenolics. These may be indicative of the higher temperature combustion and filtration during each puff. Concentrations of each gas-phase compound were estimated from a mass calibration using toluene vapor. Spectra obtained for the particle-phase contain a complex mixture of high-molecular weight compounds, as previously observed by off-line methods, but also lower molecular weight semi-volatile compounds smaller than nicotine. This gas/particle partitioning may have implications concerning how some of these compounds are absorbed upon inhalation. These compounds are present in the particle-phase and the gas-phase. The soft ionization technique showed a promising result for rapidly identifying chemical differences among cigarette types, smoke streams, and phase.

Polycyclic aromatic hydrocarbon (PAH) contamination in smoke-cured fish products

In this study, 108 fish samples of smoke cured fish Sardinella aurita (sardines/herrings) collected from 12 major fishing communities along the coastal belt of Ghana were extracted with Soxhlet apparatus using dichloromethane (DCM), and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) using the GC/MS (Varian 3800 GC system with 8400 auto-sampler) to determine levels, distribution and the characterization of their sources. The mean total PAHs in the smoked sardines from the various communities ranged from 510.59μg/kg to 1461.79μg/kg for all seasons with a mean value of 716.84μg/kg. The benzo[a]pyrene (BaP) had a maximum mean level of 73.78μg/kg. The unit risk of carcinogenic PAHs for benzo[a]pyrene, chrysene, dibenz[a,h]anthracene, benzo[a]anthracene, benzo[k]fluoranthene, benzo[b]fluoranthene, and indenol[1,2,3-cd]pyrene associated with oral ingestion of smoked sardine was calculated to be 6.1×10−7 for adults and 1.6×10−7 for children. There is a significant correlation between the fish lipid content and the total PAH levels. The average lipid content of the smoked sardine samples collected varied among the various fishing seasons (3 seasons) in Ghana. A significantly high accumulation of PAHs was found in the smoke-cured fish as compared to the non-smoke-cured fish control samples, which showed PAH levels that were below detection (0.10–2.0μg/kg). This study highlights the increased danger of consuming smoke-cured fish in Ghana as some of the PAHs are known to be carcinogenic. These results indicate that there is a need to find alternative ways of curing fish other than the traditional smoking process.

Release of PCDD/PCDF to air and land during open burning of sugarcane and forest litter over soil fortified with mass labelled PCDD/PCDF

The contribution of PCDD/PCDF emissions from soil during open burning of biomass was examined. Mass labelled PCDD/PCDF was added to soil containing native PCDD/PCDF and biomass was laid out on this soil and burnt, simulating sugarcane trash and forest fires. Smoke samples were collected using a high volume portable field sampler. After each fire the concentration of all mass labelled PCDD/PCDF congeners in the surface soil decreased, however, the concentration of some native 2,3,7,8 substituted congeners increased, indicating that formation was occurring. Mass labelled PCDD/PCDF congeners were detected in all ash samples, mean 2.8 pg g−1 (range 0.5–8 pg g−1), demonstrating release from the soil. Additionally, mass labelled PCDD/PCDF congeners were detected in all air samples mean 1.2 μg (t fuel)−1 (range 0.2–2.0 μg (t fuel)−1), again demonstrating release from the soil. Native 2,3,7,8 substituted congeners detected in the air samples were dominated (in terms of contribution to total congener mass) by Cl8DD (90% for forest litter and 77% for sugarcane). The major contributor to TEQ of emissions from both forest litter and sugarcane was 1, 2, 3, 7, 8-Cl5DD (40–64% and 57–75%, respectively). These results demonstrate that release of PCDD/PCDF from soil to air and land occurs during open burning of biomass when soil temperatures are sufficiently elevated.

Screening of commercial and pecan shell-extracted liquid smoke agents as natural antimicrobials against foodborne pathogens.

Liquid smoke extracts have traditionally been used as flavoring agents, are known to possess antioxidant properties, and serve as natural alternatives to conventional antimicrobials. The antimicrobial efficacies of commercial liquid smoke samples may vary depending on their source and composition and the methods used to extract and concentrate the smoke. We investigated the MICs of eight commercial liquid smoke samples against Salmonella Enteritidis, Staphylococcus aureus, and Escherichia coli . The commercial liquid smoke samples purchased were supplied by the manufacturer as water-based or concentrated extracts of smoke from different wood sources. The MICs of the commercial smokes to inhibit the growth of foodborne pathogens ranged from 0.5 to 6.0% for E. coli, 0.5 to 8.0% for Salmonella, and 0.38 to 6% for S. aureus. The MIC for each liquid smoke sample was similar in its effect on both E. coli and Salmonella. Solvent-extracted antimicrobials prepared using pecan shells displayed significant differences between their inhibitory concentrations depending on the type of solvent used for extraction. The results indicated that the liquid smoke samples tested in this study could serve as effective natural antimicrobials and that their inhibitory effects depended more on the solvents used for extraction than the wood source.

Wall Smoke Deposition from a Hot Smoke Layer

Smoke deposition from a hot smoke layer onto wall surfaces was studied in a hood apparatus using polymethylmethacrylate, polypropylene, and gasoline as fuels. Based upon prior analysis by Butler and Mulholland, the smoke deposition was expected to be dominated by thermophoresis. The deposited smoke samples were collected on glass filter paper attached to the hood wall and the mass per unit area of smoke deposited was measured gravimetrically. Measurements were made of quantities required for the prediction of thermophoretic smoke deposition. The smoke deposition measured in the experimental program was well predicted by the thermophoretic smoke deposition equation. The thermophoretic smoke deposition equation was found to be suitable for predicting smoke deposition onto wall surfaces exposed to fire environments.

Organic speciation of aerosols from wildfires in central Portugal during summer 2009

The aim of this study was the detailed organic speciation of fine (PM2.5) and coarse (PM2.5–10) particles and gaseous carbonyl compounds from plumes emitted by wildfires during the summer of 2009 in Portugal. Complementary characterisation of the smoke particulate inorganic fraction, along with emission factors of major trace gases, have already been published in Atmospheric Environment. The detailed speciation of organic compounds in particle samples was carried out by gas chromatography-mass spectrometry after multi-solvent extraction, flash chromatography on silica gel and appropriate derivatisation techniques. PM2.5 constitutes an important fraction of PM10 (PM2.5/PM10 > 80%). Gaseous carbonyls were sampled from the Tedlar bags containing the smoke samples in DNHP cartridges and analysed by high-performance liquid chromatography. A clear predominance of carbonaceous constituents was observed, with OC concentrations always much higher than EC in both particle size fractions (OC/EC >> 7). The chromatographically resolved organics were dominated by diterpenoids, acids, sugars, phenols and aliphatic compounds in both size fractions. Retene, a biomarker of softwood smoke, was the dominant aromatic hydrocarbon in samples. The major anhydrosugar detected was levoglucosan, followed by mannosan and galactosan. Among the measured oxygenated volatile organic compounds, the most abundant was acetaldehyde with EFs (dry basis) between 1.03 and 1.87 g kg−1, followed by formaldehyde with values in the range of 0.09–0.96 g kg−1. Propionaldehyde was the less abundant carbonyl, with values in the range of 0.03–0.17 g kg−1.

Application of Cigarette Smoke Characterisation Based on Optical Aerosol Spectrometry. Dynamics and Comparisons with Tar Values

Introduction: Cigarette smoking causes devastating disease worldwide. Current cigarette classification is based on standardised tar mass values obtained from smoking-machines. However, their ability to predict disease is poor, and these mass values are primarily determined by larger particles. The aim of our study is to investigate in how far claimed tar values also reflect smaller tar particles in cigarette smoke. Methods: We developed a method to measure size-resolved particle distributions based on experimentally selecting conditions that revealed the least variety within different smoking regimes, puff numbers, diluted and undiluted ageing times, and filter taping. Next, we analysed three cigarettes types with different tar values. Cigarettes were smoked by a Cerulean SM-450 smoking machine, and subsequently smoke samples were diluted and collected in Tedlar (R) bags and measured for size-resolved particle distributions by a universal optical aerosol spectrometer. Results: Our method involved a smoking regime according to ISO 3308, the sixth puff, and no delayed ageing. We attained valid size-resolved particle distributions between 250 and 1,000 nm. The results revealed similar total particle counts across different cigarette types, though with different size-resolved particle distributions. In particular, smaller particles in lower tar cigarettes were underestimated. Conclusion: We developed a method to investigate submicron size-resolved particle distributions in cigarette smoke in order to compare cigarettes with different tar values. Our study suggests that mass-based tar values are a poor reflection of smaller particles in mainstream cigarette smoke, and hence supports the opinion that current tar values are a poor predictor of disease-risk and therefore that they are deceptive to smokers.

Comparison of Harmful Gases Produced During GreenLight High-performance System Laser Prostatectomy and Transurethral Resection of the Prostate

To compare the gases generated from GreenLight High-Performance System (HPS) laser prostatectomy with Urosol or normal saline solution and transurethral resection and vaporization of the prostate (TURVP) with Urosol. A total of 36 smoke samples were collected from a continuous irrigation suction system attached to a Tenax absorber during transurethral surgery of the prostate. The gases were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry equipped with a purge and trap sample injector. The gas produced during TURVP contained propylene, allene, isobutylene, 1,3-butadiene, vinyl acetylene, mercaptomethane, ethyl acetylene, diacetylene, 1-pentene, ethanol, piperylene, propenylacetylene, 1,4-pentadiene, cyclopentadiene, acrylnitrile, and butyrolacton. The types and amount of gas produced during HPS laser prostatectomy were fewer and smaller than during TURVP. However, 1,3-butadiene, a well-known human carcinogen, was also generated by HPS laser prostatectomy. HPS laser prostatectomy with saline produced a greater amount and number of gases than HPS laser prostatectomy with Urosol. The surgical smoke produced from TURVP and HPS laser prostatectomy contains potentially harmful chemical compounds, although HPS laser prostatectomy produced less surgical smoke than TURVP. Urosol produced fewer types and a smaller amount of gas than normal saline during HPS laser prostatectomy.

Formation of artefacts while sampling emissions of PCDD/PCDF from open burning of biomass

Emission factors for PCDD/PCDF determined from open combustion are used to estimate national emission budgets; therefore, it is important to have confidence in their accuracy. It has been suspected that artefacts may form due to the presence of hot metal surfaces of sampling equipment, thus skewing emission factors. In this study, emissions of PCDD/PCDF from open burning of forest biomass over a brick hearth were sampled. Five experiments were carried out using a portable sampler. Experiments were designed where the key variable, sample hood and inlet temperatures were manipulated. Other variables such as fuel origin, type and density were consistent. The measured concentration of PCDD/PCDF in the smoke samples ranged from 0.01μg TEQ (t fuel)−1 at the lowest maximum hood temperature (185°C) to 15μg TEQ (t fuel)−1 at the highest maximum hood temperature (598°C). when hood inlet temperatures exceeded 400°C emission factors were significantly elevated and this is attributed to the formation of artefacts that can cause the over estimation of emission factors. The increase in hood temperature also resulted in a change in the PCDD/PCDF congener and homologue profile of the emissions. For example at the lowest temperature (Fire 1) the PCDD/PCDF ratio measured was 50:1, whereas at the highest temperature (Fire 5) this ratio was about 0.53:1. When the sampler hood and inlet temperatures were kept in the normal operating range of <200°C, emission factors were comparable to those observed in many previous studies in Australia with emissions dominated by PCDD.

Chemical analysis of surgical smoke by infrared laser spectroscopy

The chemical composition of surgical smoke, a gaseous by-product of some surgical devices—lasers, drills, vessel sealing devices—is of great interest due to the many toxic components that have been found to date. For the first time, surgical smoke samples collected during routine keyhole surgery were analyzed with infrared laser spectroscopy. Traces (ppm range) of methane, ethane, ethylene, carbon monoxide and sevoflurane were detected in the samples which consisted mostly of carbon dioxide and water vapor. Except for the anaesthetic sevoflurane, none of the compounds were present at dangerous concentrations. Negative effects on the health of operation room personnel can be excluded for many toxic compounds found in earlier studies, since their concentrations are below recommended exposure limits.

Mass absorption efficiency of elemental carbon and water-soluble organic carbon in Beijing, China

Abstract. The mass absorption efficiency (MAE) of elemental carbon (EC) in Beijing was quantified using a thermal-optical carbon analyzer. The MAE measured at 632 nm was 8.45±1.71 and 9.41±1.92 m2 g−1 during winter and summer respectively. The daily variation of MAE was found to coincide with the abundance of organic carbon (OC), especially the OC to EC ratio, perhaps due to the enhancement by coating with organic aerosol (especially secondary organic aerosol, SOA) or the artifacts resulting from the redistribution of liquid-like organic particles during the filter-based absorption measurements. Using a converting approach that accounts for the discrepancy caused by measurements methods of both light absorption and EC concentration, previously published MAE values were converted to the equivalent-MAE, which is the estimated value if using the same measurement methods as used in this study. The equivalent-MAE was found to be much lower in the regions heavily impacted by biomass burning (e.g., below 2.7 m2 g−1 for two Indian cities). Results from source samples (including diesel exhaust samples and biomass smoke samples) also demonstrated that emissions from biomass burning would decrease the MAE of EC. Moreover, optical properties of water-soluble organic carbon (WSOC) in Beijing were presented. Light absorption by WSOC exhibited strong wavelength (λ) dependence such that absorption varied approximately as λ−7, which was characteristic of the brown carbon spectra. The MAE of WSOC (measured at 365 nm) was 1.79±0.24 and 0.71±0.20 m2 g−1 during winter and summer respectively. The large discrepancy between the MAE of WSOC during winter and summer was attributed to the difference in the precursors of SOA such that anthropogenic volatile organic compounds (AVOCs) should be more important as the precursors of SOA in winter. The MAE of WSOC in Beijing was much higher than results from the southeastern United States which were obtained using the same method as used in this study, perhaps due to the stronger emissions of biomass burning in China.

Chemical analysis of incense smokes used in Shaxi, Southwest China: A novel methodological approach in ethnobotany

Aim of the studyCharacterization and comparative analysis of the main VOCs (volatile organic compounds) present in the smoke of 11 experimentally combusted plant species used as incense in Shaxi, Southwest China. Substances which may be responsible for the pleasant smell of the smokes as well as substances with a potential pharmacological activity are discussed. Materials and methodsWe adopt the dynamic headspace sorption method for the collection of smoke samples as a novel methodological approach in ethnobotany. The VOCs were identified using gas chromatography–mass spectrometry (GC–MS). Principal component analysis and canonical discriminant analysis were performed using PASW statistics (Version 18.0.2). ResultsAmong the identified compounds were 10 monoterpenoids, 7 sesquiterpenoids, 6 linear hydrocarbons, 6 methoxy phenolics, 2 benzenoids, 2 polycyclic aromatic hydrocarbons, and 2 fatty acids. Based on their volatile profiles, the species are well clustered intraspecifically and separated interspecifically. The most abundant among the compounds potentially responsible for the pleasant smells of the smokes are methyl salicylate (12.28±3.90%) for Gaultheria fragrantissima leaves, δ-cadinene (15.58±2.29%) for Juniperus squamata wood, and α-Pinene for Cupressus funebris branches (9.16±7.73%) and Pistacia weinmanniifolia branches (19.52±8.66%). A couple of substances found are known for pharmacological activity, such as methylsalycilate, beta-caryophyllene and cedrol. ConclusionsThe species used by the local people in Shaxi for incense differ clearly with respect to the chemical compounds of their smoke. Further, incense contains substances, which are of pharmacological interest and might support medicinal uses of smoke. Cedrol with its pleasant smell and sedative properties may be an important factor why specific plants are chosen as incense. Our findings support the idea that the effects of the use of incense as well as medicinal smoke depend on both, the cultural as well as the pharmacological context.

A single-blind controlled study of electrocautery and ultrasonic scalpel smoke plumes in laparoscopic surgery

Surgical smoke containing potentially carcinogenic and irritant chemicals is an inevitable consequence of intraoperative energized dissection. Different energized dissection methods have not been compared directly in human laparoscopic surgery or against commonly encountered pollutants. This study undertook an analysis of carcinogenic and irritant volatile hydrocarbon concentrations in electrocautery and ultrasonic scalpel plumes compared with cigarette smoke and urban city air control samples. Once ethical approval was obtained, gas samples were aspirated from the peritoneal cavity after human laparoscopic intraabdominal surgery solely using either electrocautery or ultrasonic scalpels. All were adsorbed in Tenax tubes and concentrations of carcinogenic or irritant volatile hydrocarbons measured by gas chromatography. The results were compared with cigarette smoke and urban city air control samples. The analyzing laboratory was blinded to sample origin. A total of 10 patients consented to intraoperative gas sampling in which only one method of energized dissection was used. Six carcinogenic or irritant hydrocarbons (benzene, ethylbenzene, styrene, toluene, heptene, and methylpropene) were identified in one or more samples. With the exception of styrene (P = 0.016), a nonsignificant trend toward lower hydrocarbon concentrations was observed with ultrasonic scalpel use. Ultrasonic scalpel plumes had significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of methylpropene (P = 0.332). No significant difference was observed with city air. Electrocautery samples contained significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of toluene (P = 0.117) and methyl propene (P = 0.914). Except for toluene (P = 0.028), city air showed no significant difference. Both electrocautery and ultrasonic dissection are associated with significantly lower concentrations of the most commonly detected carcinogenic and irritant hydrocarbons than cigarette smoke. A nonsignificant trend toward lower hydrocarbon concentrations was seen with ultrasonic scalpel dissection compared with diathermy. The contamination levels in city air were largely comparable with those seen after ultrasonic scalpel use. Although hydrocarbon concentrations are low, cumulative exposures may increase health risks. Where concerns arise, ultrasonic scalpel dissection may be preferable.

New Device Measures Atmospheric Isocyanic Acid

Isocyanic acid (chemically HNCO), a contaminant linked to cataracts and heart disease, has for the first time been measured in the atmosphere.1 The discovery was made by researchers at the National Oceanic and Atmospheric Administration (NOAA) who designed a new detection system to measure HNCO in environments where conventional methods could not previously detect it. Study leader James Roberts and colleagues developed a specialized negative-ion proton-transfer chemical ionization mass spectrometer to measure organic acids emitted by wildfires2 [look for more information on health effects of wildfires in the September 2011 issue of EHP]. They tested the instrument on brush and tree branches burned in a test chamber, which generated levels of HNCO reaching 600 ppbv. Next they used the device on air samples collected in Boulder, Colorado, during the 2010 Fourmile Canyon wildfire and ambient air samples collected in downtown Los Angeles, California. These samples yielded HNCO concentrations up to 200 pptv and 100 pptv, respectively. No wildfires were burning near Los Angeles at the time, so “we assume isocyanic acid came from vehicle exhaust or photochemical reactions known to make it,” Roberts says. The investigators also observed HNCO in laboratory samples of cigarette smoke but noted “the levels were too high for us to quantify with the . . . instrument configured in the ambient measurement mode.” Drawing on a surrogate pyrolysis study that found nearly all the urea in tobacco decomposes to HNCO during burning,3 the researchers calculated mainstream cigarette smoke may contain 40–140 ppmv HNCO.1 Urea is added to cigarettes to enhance flavor. Urea is also used in selective catalytic reduction systems to break down toxic nitrogen oxides (NOX) in diesel exhaust into nitrogen and water. Roberts wants to measure HNCO emitted by these systems, which the European Union mandates for heavy-duty diesel trucks; a similar law is pending in California.4 “In trying to solve the problem of NOX we could be increasing HNCO,” Roberts says. The health effects of chronic exposure to environmental HNCO are unknown, although Roberts and colleagues note the concentrations they measured in smoke “cause carbamylation at physiologically significant levels.”1 In carbamylation, cyanate binds the amino acid lysine in proteins to form homocitrulline. Stanley Hazen, section head of Preventive Cardiology and Rehabilitation at the Cleveland Clinic, found that high blood levels of homocitrulline are a strong predictor of heart disease, especially in smokers, offering a possible mechanism linking smoking to atherosclerosis.5 “We assumed the exogenous source of cyanate in our study was smoking,” Hazen says. Now Roberts’ study suggests HNCO from air pollution also may increase cardiovascular disease risk. “Any degree of carbamylation has potential to be harmful,” Hazen says, although the levels required to raise cardiac and other health risks remain to be determined.

Measurement of trace gases and organic compounds in the smoke plume from a wildfire in Penedono (central Portugal)

Abstract Gas and particulate fractions were measured simultaneously from a wildfire in Penedono, central Portugal, which occurred in summer 2009. The total volatile hydrocarbons (THC) and carbon oxides (CO 2 and CO) collected in Tedlar bags were measured using automatic analysers with flame ionisation and non-dispersive infrared detectors, respectively. Carbonyls (formaldehyde and acetaldehyde) were sampled from the Tedlar bags in DNHP cartridges and analysed by high-performance liquid chromatography. Fine (PM 2.5 ) and coarse (PM 2.5-10 ) smoke particles were collected sequentially, on pre-fired quartz fibre filters, with a portable high-volume sampler. The detailed speciation of organic compounds in smoke samples was carried out by gas chromatography-mass spectrometry. The organic and elemental carbon content of particulate matter was analysed by a thermal-optical transmission technique. Average emission factors of 1.86 ± 0.80 and 0.063 ± 0.066 g kg −1 (dry basis) were obtained for acetaldehyde and formaldehyde, respectively. The THC, CO, CO 2 , PM 2.5 , PM 10 , OC and EC emission factors (g kg −1 fuel burned, dry basis) were 260 ± 88, 268 ± 92, 1200 ± 172, 37 ± 12.2, 40 ± 12.6, 21 ± 6.7 and 0.44 ± 0.21, respectively. The chromatographically resolved organics included n -alkanes, n -alkenes, n -alkanoic acids, n -di-acids, unsaturated fatty acids, phenolic compounds, ketones, steroids, di- and triterpenoids, PAHs, with retene as the major compound, oxygenated PAH and anhydrosugars.

Smoke oxidation kinetics for application to prediction of clean burn patterns

SUMMARYSmoke deposition patterns are a potentially rich source of information concerning the behavior of a fire. Clean burn patterns are smoke‐free areas where smoke deposits have been oxidized away. In order to predict the formation of clean burn patterns, smoke oxidation kinetics are required. Smoke oxidation kinetics were studied for smokes from acrylonitrile butadiene styrene, polymethylmethacrylate, polypropylene, and gasoline. The fuels were burned below a hood, and smoke samples were collected from the hot gas layer and from the wall surfaces. The smokes from various polymers and gasoline were found to contain no measurable volatile organic chemicals. The kinetics of the smokes from the polymers and gasoline were found to be satisfactorily modeled as first order in both smoke and oxygen with the same kinetic constants for all fuels tested. The activation energy was calculated to be 211 kJ/mol, and the pre‐exponential factor was found to be 4.7 × 1010/s. These kinetic parameters provide a basis for modeling clean burn pattern generation. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Atmospheric tar balls from biomass burning in Mexico

[1] Atmospheric tar balls (TBs) are spherical, organic aerosol particles that occur in smoke from biomass burning (BB). They absorb sunlight and thereby cause warming of the atmosphere. This study reports a transmission electron microscope (TEM) study of TBs from BB smoke samples collected within minutes to hours from emission in a tropical area of Mexico. Their spherical shapes as seen in both scanning electron microscope images and with electron tomography indicate that they were solid when collected. They consist of C and minor O, S, K, and N. The hygroscopic growth factor for our relatively fresh TBs is 1.09 ± 0.04 at a relative humidity of 100%. In samples 1.6 km from the fire, an average of ∼1 and 14%, respectively, of particles with aerodynamic diameter from 50 to 300 nm consisted of TBs. For the latter, more aged samples, the total volume was roughly double that of soot, and their total calculated light absorption at a wavelength of 550 nm was between 74 and 96% that of soot, with the exact amount depending on the size, shape, and coating of the soot. In general, the TBs that we analyzed were similar to those from North America, southern Africa, and Europe in terms of size, external mixing, relative freedom of inclusions, and composition. This and previous studies show that TBs result from a range of biomass fuels. Their distribution from various regions across the globe, combined with their optical properties, suggests they have important effects on regional and perhaps global climate.

Chemical Production in Electrocautery Smoke by a Novel Predictive Model

Objectives: The hazards of electrocautery smoke have been known for decades. However, few clinical studies have been conducted to analyze the responsible variables of the smoke production. This study collected clinical smoke samples and systematically analyzed all possible factors. Methods: Thirty diathermy smoke samples were collected during mastectomy and abdominal cavity operations. Samples were analyzed using a gas chromatographer with a flame ionization detector. Data were applied to construct prediction models for chemical production from electrosurgeries to identify all possible factors that impact chemical production during electrosurgery. Results: Toluene was detected in 27 smoke samples (90%) with concentrations of 0.003–0.463 mg/m³ and production of 176.0–2,780.0 ng. Ethyl benzene and styrene were identified in very few cases. General linear regression analysis demonstrates that surgery type, patient age, electrocautery duration and imparted coagulation energy explained 67.63% of the variation in toluene production. Conclusion: Surgery type and patient age are known prior to surgery. In terms of risk precaution, the operating team should pay close attention to exposure when certain positive factors of increasing the chemical production are known in advance.

Evaluation of Two Derivatization Reagents for the Determination by LC-MS/MS of Ammonia in Cigarette Mainstream Smoke

Ammonia in cigarette mainstream smoke was quantified by LC-MS/MS after derivatization. Two different reagents, fluorescamine and dansyl chloride, were investigated, but only the latter gave stable derivatives; therefore, it was considered the most appropriate choice. Smoke samples were collected on a Cambridge filter pad followed by an impinger containing a solution of hydrochloric acid. Ammonia was then derivatized with a 18.5 mM solution of dansyl chloride in acetonitrile at 70 °C for 30 min in a vial with the internal standard, (15)ND(4)Cl. The resulting derivative was analyzed by LC-MS/MS detection with an atmospheric pressure chemical ionization (APCI) interface in the positive ionization mode using multiple-reaction monitoring (MRM). Good linearity was obtained in the concentration range of 0.02-1.65 μg/mL (r(2) ≥ 0.999), and the limit of detection (LOD) was established at 0.006 μg/mL. This method has the advantage of being sensitive, efficient, and reliable and is not hindered by interferences from the sample matrix. It should thus be considered a reference method of choice for the determination of ammonia in smoke.