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1.
A liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of nicotine and seven minor tobacco alkaloids in both refill liquids for electronic cigarettes and their generated aerosol was developed and validated. The limit of detection and limit of quantification values were 0.3–20.0 and 1.0–31.8 ng/mL, respectively. Within‐laboratory reproducibility was 8.2–14.2% at limit of quantification values and 4.8–12.7% at other concentration levels. Interday recovery was 75.8–116.4%. The method was applied to evaluate the compliance of commercial liquids (n = 95) with their labels and to assess levels of minor alkaloids. Levels of nicotine and its corresponding compounds were also evaluated in generated aerosol. About 47% of samples showed differences above ±10 % of the stated nicotine concentration. About 78% of the “zero nicotine” liquids showed traces in the range of 1.3 ± 0.1–254.0 ± 14.6 μg/mL. Nicotine‐N ′‐oxides, myosmine, and anatabine were the most common minor alkaloids in liquids containing nicotine. Nicotine and N ′‐oxides were detected in all air samples when aerosol was generated from liquids containing nicotine. Nicotine average emissions from electronic cigarette (2.7 ± 0.9 μg/m3) were significantly lower (p < 0.01, t‐test) with respect to conventional cigarette (30.2 ± 1.5 μg/m3).  相似文献   

2.
Summary The sampling approaches using solid phase microextraction (SPME) were evaluated for the analysis of tobacco alkaloids. Because of their low volatility and ionic nature, sampling alkaloids from the headspace of dry or wet tobacco samples often required more effort to improve extraction efficiency. Directly dipping the SPME fiber coated with polydimethylsiloxane film into the tobacco extract was proved to be a simple, effective tool for sampling alkaloids from tobacco. When combined with the practice of fast GC and nitrogen-phosphorus detection, nicotine and a group of selected minor alkaloids (i.e., nornicotines, myosmine, anabasine and anatabine) were separated with baseline resolution within 3 min. The detection limits for these alkaloids are below 0.1 μg mL−1. In addition, the carry-over problem frequently occurred in alkaloids analysis was eliminated. The influence of tobacco matrix and fiber aging on the partition of alkaloids, as well as the use of an internal standard to compensate these deviations, were also studied.  相似文献   

3.
In the course of routine surveillance for indoor radon in Austria, concentrations above 10,000 Bq/m3 were found in a house in the province of Carinthia, Austria. Multiple 3-day-measurements in all the rooms of the house were carried out for the next 21 months. All rooms of the house had elevated radon concentrations but radon levels decreased systematically from east to west within the house. Moreover, radon concentrations in one room of the building were found to be below 300 Bq/m3 in winter but above 12,000 Bq/m3 in summer. After installing a medium sized fan, operated only during the summer season, the semiannual summer radon levels dropped from approximately 8,000 Bq/m3 to 250 Bq/m3 at ground floor level. Note: The paper reflects the personal opinions of the authors.  相似文献   

4.
A method has been developed for the determination of acrylamide at the picogram per cubic metre level in particulate-phase outdoor aerosol using high-performance liquid chromatography with triple quadrupole tandem mass spectrometric detection. Acrylamide was identified by positive ion electrospray mass spectrometry using m/z 72.00/54.90 as monitoring ion transition. The limit of detection, defined as three times the standard deviation of the procedural blanks, was 0.4?pg?m?3 (173?pg absolute amount injected); the repeatability was 8% (evaluated as the relative standard deviation of five consecutive measurements on cleaned quartz fibre filters of acrylamide standard spikes) and the recovery was 52?±?4%. The accuracy of the method (evaluated as relative error) has been estimated to be ?2%. This methodology was used to determine acrylamide concentrations in particulate-phase outdoor aerosol in the Venice Lagoon with concentrations ranging between 0.4 and 12.9?pg?m?3 with an average value of 3.1?pg?m?3.  相似文献   

5.
Several phenolic compounds are present in tobacco smoke. They are formed from the pyrolysis of tobacco during the smoking process and all of them are toxic. Therefore, the determination of these compounds in air samples is important. A rapid, simple, and sensitive method using a synchronous spectrofluorimetry technique was developed to quantify hydroquinone and resorcinol simultaneously. One of the advantages of this method is the simple and rapid sampling technique, which uses water as the absorption solution of the analytes in the air sample. The precision of the method (%RSD) was 1.8% and the detection limits were 0.125 mg m–3 and 0.292 mg m–3 for hydroquinone and resorcinol, respectively.  相似文献   

6.
A method using GC-MS and derivatization with N-(t-butyldimethylsilyl)-N-ethyltrifluoroacetamide (MTBSTFA) was developed for the analysis of 19 chlorophenols compounds in atmospheric samples (gas and particles). Air sampling was carried out using a Hi-Vol sampler with glass fibre filter and XAD-2 resin at a flow rate of 60 m3 h−1. The particle and gas phases were collected separately over a period of 4 h. Samples were Soxhlet extracted, evaporated to dryness under nitrogen and refilled with acetonitrile. 100 mL of these extracts were derivatized with 100 μL of MTBSTFA at 80 °C for 1 h under strong stirring. Sylylated chlorophenols were injected into a GC-MS in splitless mode and quantified as their TBDMS derivatives in the SIM mode. Mass spectral analysis of the derivatives of the 19 compounds studied indicates that the spectra are highly specific showing an ion at [M - 57]+ which is useful for structure confirmation or analysis at low levels using selected ion monitoring. Quantification limits varied between 5 μg L−1 and 10 μg L−1 which correspond to 20 pg m−3 and 40 pg m−3 for 250 m3 of air sampled. This method was successfully applied to atmospheric samples collected simultaneously in winter 2004 in an urban (Strasbourg) and rural (Erstein) areas in east of France.  相似文献   

7.
Comparison of methods for extraction of tobacco alkaloids   总被引:7,自引:0,他引:7  
Ultrasound and microwave techniques were used to extract tobacco alkaloids, and response surface methodology was used to optimize extraction conditions. Ultrasonic technique factors were temperature, 30-85 degrees C; time, 3-45 min; solvent volume, 8-80 mL. Microwave extraction factors were pressure, 15-75 psi; time, 3-40 min; power, 30-90% of the maximum magnetron power of 650 W. Soxhlet and solvent AOAC-modified extraction methods were also applied after some improvements. Nicotine, nornicotine, anabasine, and anatabine were quantified by gas chromatography. A steam distillation International Standards Organization method for total alkaloid evaluation was used as reference. The results obtained by the different methods were compared using a least squares deviation test. The ultrasonic and the proposed modified-AOAC extraction method were the more convenient with regard to practicability and precision. The relative deviations (n = 5) were as follows: For the ultrasonic method in low-level alkaloid tobaccos, 0.7% nicotine and 1.4-14% minor alkaloids; in high-level alkaloid tobaccos, 2.4% nicotine and 4.5-5.1% minor alkaloids. For the modified AOAC method in low-level alkaloid tobaccos, 0.9% nicotine and 2.4-11.6% minor alkaloids; and in high-level alkaloid tobaccos, 1.7% nicotine and 2.0-2.4% minor alkaloids.  相似文献   

8.
Summary Fourteen polychlorinated biphenyl (PCB) congeners were quantified in air samples of the tropospheric boundary layer of the Atlantic Ocean. The samples were taken on the German research vessel Polarstern during north-south cruises across the Atlantic Ocean (1990, 1991), and on the Capo Verde islands in the North Atlantic Ocean (1992). Values for the sum of PCB were between 48 pg/m3 (values for the seven indicator congeners were [in pg/m3]: PCB 28: 1.3; PCB 52: 5.0; PCB 101: 3.0; PCB 118: 0.5; PCB 138: 1; PCB 153: 1; PCB 180: <0.2) in the Westwind Belt of the eastern North Atlantic and 22 pg/m3 (values for the seven indicator congeners were [in pg/m3]: PCB 28: 2.3; PCB 52: 3.4; PCB 101: 0.5; PCB 118: <0.2; PCB 138: <0.2; PCB 153: <0.2; PCB 180: <0.2) in the Westwind Belt of the central South Atlantic. Up to 385 pg/m3 (values for the seven indicator congeners were [in pg/m3]: PCB 28: 2.6; PCB 52: 11.7; PCB 101: 28.4; PCB 118: 9; PCB 138: 21; PCB 153: 18; PCB 180: 5.5) were measured of the coast of South Patagonia. A difference depending on latitude and on terrestrial influenced air masses between the lower and the higher chlorinated congeners was observed. The levels of three- and tetrachlorinated congeners were highest in the Trade Wind regions. The contents of the higher chlorinated congeners had maxima in samples influenced by continental air masses. A correlation of the levels of the lower chlorinated congeners in air over the South Atlantic with the surface water temperature and thus with the temperature dependent gas/water partition coefficient Kgw was observed. Part XVI: Fischer RC, Krämer W, Ballschmiter K (1991) Chemosphere 23:889–900  相似文献   

9.
Passive smoking due to environmental tobacco smoke is a serious public health concern because it increases the risk of lung cancer and cardiovascular disease. However, the current status and effect of passive smoking in various lifestyles are not fully understood. In this study, we measured hair nicotine and cotinine levels as exposure biomarkers in non-smokers and assessed the risk from the actual situation of passive smoking in different lifestyle environments. Nicotine and cotinine contents in hair samples of 110 non-smoker subjects were measured by in-tube solid-phase microextraction with on-line coupling to liquid chromatography-tandem mass spectrometry, and self-reported lifestyle questionnaires were completed by the subjects. Nicotine and cotinine were detected at concentrations of 1.38 ng mg−1 and 12.8 pg mg−1 respectively in the hair of non-smokers, with levels significantly higher in subjects who reported being sensitive to tobacco smoke exposure. These levels were also affected by type of food intake and cooking method. Nicotine and cotinine in hair are useful biomarkers for assessing the effects of passive smoking on long-term exposure to environmental tobacco smoke, and our analytical methods can measure these exposure levels in people who are unaware of passive smoking. The results of this study suggest that the environment and places of tobacco smoke exposure and the lifestyle behaviors therein are important for the health effects of passive smoking.  相似文献   

10.
Atmospheric concentrations of Dechlorane Plus(DP)were investigated in Taizhou,an electronic-waste(E-waste)dismantling region in East China.Passive air samplers with polyurethane foam(PUF)disks were deployed every three months during the sampling period of September 2009-August 2010.The total DP(syn-and anti-DP)concentrations in air ranged from not detected to 277 pg/m~3,with a mean concentration of 53.9 pg/m~3.A generally declining trend of DP levels was found from the E-waste dismantling region to the peripheral areas.The median values of total DP concentrations in autumn,winter,spring and summer were 52.2,28.8,39.7 and 30.1 pg/m~3,respectively.The seasonal variations of DP concentrations were mainly associated with the intensity of E-waste dismantling activities and meteorological conditions.The mean value of anti-DP fractional abundance(f_(anti))was 0.74±0.08,which was consistent with those in the commercial DP products.This study confirmed a significant emission source related to the distribution of atmospheric DP in the E-waste dismantling area and supplied information for the seasonal variation of DP in the atmosphere.  相似文献   

11.
Some recent Italian laws, based on the Euratom Directive 26/96, introduce the obligation of monitoring the exposition to natural radioactivity in particular worksites (thermal baths, mines, basements, etc.). This paper reports the results of 222Rn measurements in some thermal baths of Rimini and Pesaro-Urbino provinces (Central Eastern Italy), by Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha-track detectors. Some areas where radon could accumulate (bathing, reaction, muddy, inhalation, insufflation rooms and swimming pools) were selected for the investigation. The dosimeters have been exposed for 98 days. The results show that 222Rn concentrations are very low in the considered thermal baths (7-71 Bq.m-3). Moreover, no difference was observed between the concentrations measured in the therapy rooms (bathing, muddy, inhalation and insufflation rooms, swimming pools) and in the normal areas (passages, reaction rooms, dressing rooms, etc.). The calculated dose contribution to workers was about one tenth of the legally suggested value. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

12.
Eight PM10 aerosol samples were collected in the vicinity of the “Mario Zucchelli” Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000–2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84–9.2 μg g−1 (average 4.7 μg g−1), Pb 13.2–81 μg g−1 (average 33 μg g−1), Cu 126–628 μg g−1 (average 378 μg g−1). In terms of atmospheric concentration, the values were: Cd 0.55–6.3 pg m−3 (average 3.4 pg m−3), Pb 8.7–48 pg m−3 (average 24 pg m−3), Cu 75–365 pg m−3 (average 266 pg m−3). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90–100%, and lower for Cu, 70–90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (∼10% and ∼5%, respectively), while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions (possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source. Figure Aerosol sampling in Antarctica  相似文献   

13.
Aerosol particles with a minimum diameter of 0.1 μm were sampled with an impactor at various places in three class 1000 clean-room complexes. The elemental composition of the integral samples was determined by total reflection X-ray fluorescence (TXRF) analysis. With this new application and a combination of tried and tested sampling and analysing methods it was possible to detect elements in the pg m−3 range in clean rooms. The elemental composition of single particles was analysed by electron probe microanalysis (EPMA). Furthermore, EPMA elemental maps can yield further valuable information on the homogeneous structure of particles and quantitative particle analysis can lead to respective compound identification.  相似文献   

14.
Bai  Yongzhi  Li  Changyu  Zhao  Jinghui  Zheng  Peihe  Li  Yali  Pan  Yongqi  Wang  Yingping 《Chromatographia》2013,76(11):635-642

A high yield method to extract alkaloids from Aconitum coreanum using pulsed electric field (PEF) was developed, and the optimized extraction method compared to the other four extraction methods, consisting of cold maceration extraction, percolation extraction, heat reflux extraction (HRE), and ultrasonic-assisted extraction (UE). The experimental factors of the extraction methods such as electric field intensity, pulse frequency and solid-to-solvent ratio were evaluated. The content of Guanfu base A (GFA) was quantified by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The results indicated that the highest yield of GFA was 3.94 mg g−1 by PEF with conditions of 20 kV cm−1 electric field intensity, 8 pulse, 1:12 solid-to-solvent ratio, and 90 % ethanol–water solution. Meanwhile, the extraction time of PEF was <1 min, which is much less than the HRE of 10 h and even the newly used technique UE of 40 min. Moreover, the results of PEF extraction method showed obvious advantages, with the highest efficiency (120 L h−1), the shortest extraction time (0.5–1 min), and the lowest energy costs, which could be applied in the industrial production of alkaloids from A. coreanum. Therefore, the application of the PEF extraction method is a promising and constructive method for extraction of GFA.

  相似文献   

15.
Summary A method has been developed for the determination of very low concentrations (pg/m3) of organic chlorinated compounds in air. Chlorinated benzenes, hexachlorocyclohexanes, polychlorinated biphenyls and the DDT group. Since most of the atmospheric burden of such compounds occurs in the gas phase, a high volume sampling method has been developed using carefully precleaned polyurethane foam as collection medium. Samples of 2000–4000 m3 were taken at different sites in the Arctic. The foam quality as well as the precleaning procedure of the foam and the clean-up of the sample are described in detail. The recovery of both the extraction and sample pretreatment was in the range of 80–115% for nanogram amounts. Sampling efficiency for the first foam plug was 80–100%.The sampling efficiency is influenced by different factors (temperature, air humidity, sampling volume). For quantification and identification, the highly selective methods of negative ion chemical ionization mass spectrometry and electron capture detection were combined with high resolution gas chromatography. The detection limit of the method was for most compounds less than a few pg/m3. Some preliminary data from the Arctic measurements are presented and are briefly discussed.
Quantitative Bestimmung von Ultraspuren chlorierter Verbindungen in großvolumigen Luftproben aus der Arktis mit Hilfe von Polyurethanschaum als Sammelmedium
Zusammenfassung Das beschriebene Verfahren dient zur Bestimmung von chlorierten Verbindungen (chlorierte Benzole, Hexachlorcyclohexane, polychlorierte Biphenyle, DDT-Gruppe) in niedrigen Konzentrationen (pg/m3) in Luft. Da die meisten dieser Verbindungen gasförmig vorkommen, wurde eine Probenahmemethode für große Volumina unter Verwendung von sorgfältig vorgereinigtem Polyurethanschaum als Adsorptionsmedium entwickelt. Proben von 2000–4000 m3 wurden an verschiedenen Stellen der Arktis genommen. Die Vorbehandlung des Schaums und der Probe wird ausführlich beschrieben. Bei ng-Mengen lag die Wiederfindung bei 80–115%. Die Leistungsfähigkeit der ersten Schaumschicht lag bei 80–100%. Durch Temperatur, Luftfeuchtigkeit und Probenahmevolumen wird die Leistungsfähigkeit beeinflußt. Zur Identifizierung und quantitativen Bestimmung wurde die Negativionen-Massenspektrometrie mit chemischer Ionisation und die EC-Detektion mit der Hochleistungs-Gas-Chromatographie kombiniert. Die Nachweisgrenze lag für die meisten Verbindungen bei weniger als einigen pg/m3. Einige Daten der arktischen Messungen werden vorgestellt und kurz diskutiert.


Partly presented at the Fourth European Conference on Analytical Chemistry, Helsinki/Espoo, Finland 1981  相似文献   

16.
A high yield method to extract alkaloids from Aconitum coreanum using pulsed electric field (PEF) was developed, and the optimized extraction method compared to the other four extraction methods, consisting of cold maceration extraction, percolation extraction, heat reflux extraction (HRE), and ultrasonic-assisted extraction (UE). The experimental factors of the extraction methods such as electric field intensity, pulse frequency and solid-to-solvent ratio were evaluated. The content of Guanfu base A (GFA) was quantified by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The results indicated that the highest yield of GFA was 3.94 mg g?1 by PEF with conditions of 20 kV cm?1 electric field intensity, 8 pulse, 1:12 solid-to-solvent ratio, and 90 % ethanol–water solution. Meanwhile, the extraction time of PEF was <1 min, which is much less than the HRE of 10 h and even the newly used technique UE of 40 min. Moreover, the results of PEF extraction method showed obvious advantages, with the highest efficiency (120 L h?1), the shortest extraction time (0.5–1 min), and the lowest energy costs, which could be applied in the industrial production of alkaloids from A. coreanum. Therefore, the application of the PEF extraction method is a promising and constructive method for extraction of GFA.  相似文献   

17.

This study aims to: (1) Acquire the radon level in closed office rooms, providing radon exposure data for preliminary health risk assessment of office-working population. (2) Pre-analyze the relationship between radon concentration and indoor temperature, relative humidity. (3) Estimate seasonal, annual and total radon effective dose for ordinary office-working population. The results show that the 24-h or 8-h average radon concentrations in closed office rooms were about 32.0 Bq/m3 and 29.5 Bq/m3 during detection period, and the estimated effective doses in office rooms calculated by using 24-h and 8-h average radon concentrations were all far below that in residential environment.

  相似文献   

18.
Summary Halogenated methoxybenzenes (halogenated anisoles) and hexachlorobenzene (HCB) have been analyzed in marine air samples from the lower troposphere of the East Atlantic Ocean, taken on the German, research vessel ‘Polarstern’ during two cruises in 1993 and 1994, and in air samples from the North Pacific Ocean (1995). The high-volume sampling method, sample preparation and analysis by HRGC-ECD and HRGC-MSD-SIM are described. The effectiveness of a new graphitized-carboncovered silica sorbent (ANGI-Sorb B) for the sampling of semi-volatiles is demonstrated. Eight congeners of the halogenated anisoles and HCB were detected in almost all marine air samples. The concentrations of the chloroanisoles, which show a distinct north-south interhemispherical gradient, were between 0.2 and 145 pg m−3; for the bromaanisoles concentrations were between 0.2 and 42 pg m−3. Only a weak inter-hemispheric gradient was observed for HCB at levels of 10–40 pg m−3. Levels of HCB were approximately 100 pg m−3 in continentally influenced air. Biogenic and indirect anthropogenic sources of the halogenated anisoles are discussed. Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996  相似文献   

19.
Leaves of Zanthozvlumprocerum (Rutaceae) yielded two major optically inactive alkaloids, culantraramine and culantraraminol, which were assigned bishordeninyl terpene structures based upon spectral evidence and conversions to known alkaloids. Two minor alkaloids, isomeric with culantraraminol, were also found, along with hordenine and N,N-dimethyltryptamine. Although culantraramine could be viewed as a natural self Diels-Alder adduct of dehydropronylhordenine, when this diene was prepared and reacted, it yielded instead an alternate adduct. This room temperature Diels-Alder reaction does, however, represent a model for the biosynthesis of some other known isolates considered as natural Diels-Alder adducts. A total synthesis of culantraramine and culantraminol was instead achieved in high yield from a prenylalcohol precursor under mild acid conditions. The synthetic reaction also yielded the two minor culantraraminol isomers. All four alkaloids were present in similar amounts in both the synthetic mixture and the crude leaf extract. The reaction used in the synthesis of culantraramine and culantraraminol is suggested to be biomimetic for these and certain other dimeric alkaloids.  相似文献   

20.
Active and passive smoking are serious public health concerns Assessment of tobacco smoke exposure using effective biomarkers is needed. In this study, we developed a simultaneous determination method of five tobacco-specific nitrosamines (TSNAs) in hair by online in-tube solid-phase microextraction (SPME) coupled to liquid chromatography-tandem mass spectrometry (LC–MS/MS). TSNAs were extracted and concentrated on Supel-Q PLOT capillary by in-tube SPME and separated and detected within 5 min by LC–MS/MS using Capcell Pak C18 MGIII column and positive ion mode multiple reaction monitoring systems. These operations were fully automated by an online program. The calibration curves of TSNAs showed good linearity in the range of 0.5–1000 pg mL–1 using their stable isotope-labeled internal standards. Moreover, the limits of detection (S/N = 3) of TSNAs were in the range of 0.02–1.14 pg mL–1, and intra-day and inter-day precisions were below 7.3% and 9.2% (n = 5), respectively. The developed method is highly sensitive and specific and can easily measure TSNA levels using 5 mg hair samples. This method was used to assess long-term exposure levels to tobacco smoke in smokers and non-smokers.  相似文献   

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