Determination of 27 volatile organic compounds in exhaled breath by thermal desorption-gas chromatography-mass spectrometry / 环境与职业医学

Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min−1 for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min−1 for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol−1, the limits of quantification were in the range of 0.02-0.44 nmol·mol−1, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol−1. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.

Production of Bioethanol from Sugarcane Bagasse Using Saccharomyces Cerevisiae

Ethanol is an alternative fuel derived from renewable biological resources. It's a good substitute for gasoline in spark ignition engines. In this study, the sugar cane bagasse was chemically pretreated with 1% NaOH at room temperature for 2 hours. Dilute acid H2SO4 and Aspergillus niger was used to hydrolyse the biomass to sucrose. Fermentation of the hydrolysed sample was done using Saccharomyces cerevisiae. The fermented product was purified by distillation process at 78oC, and the fraction was collected, and the ethanol was determined by measuring the specific gravity. The production of ethanol from sugar cane bagasse with Saccharomyces cerevisiae was determined after the inoculation into sample A1, A2 and B1 and B2 and highest ethanol produced were from B1 with 0.090 followed B2 0.074, A2 with 0.069% and D 0.116. The use of Saccharomyces cerevisiae gives a better yield. The result of this study can be of a better application in the large production of biofuel from sugar cane bagasse which is renewable and highly abundant, it is saving costs by recycling of wastes, and it also helps to alleviate environmental problem such as an excessive release of greenhouse gases from combustion of non-renewable fossil fuel. From the chromatograph, when the peaks spectrum wave analysed by mass spectrometer of the three volatile organic compounds, two were common to both samples, A contains the abundance of Acetic acid 22.37%, Ethyl alcohol 13.55% isobutene 64.08%. While that of Sample B contains the abundance Acetic acid 17.43%, Ethyl alcohol 7.12% and Propane 75.4.according to Pasteur this is due to Microbial oxidation of ethanol to acetic acid that decreases metabolic toxicity to the yeast cells. This study has proven the efficiency of Saccharomyces cerevisiae for the production of bioethanol.

Comparison of volatile organic compounds between cigarette smoke condensate (CSC) and extract (CSE) samples

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.

Comparison of volatile organic compounds between cigarette smoke condensate (CSC) and extract (CSE) samples

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.

Thermal Desorption-Gas Chromatography or Gas Chromatograph-Mass Spectrometry for Analysis of Semi-Volatile Compounds on Atmospheric Particulate Matters / 分析化学

A thermal desorption ( TD) device was developed and coupled to gas chromatography ( GC) or gas chromatography-mass spectrometry ( GC-MS ) for the qualitative and quantitative analysis of semi-volatile organic compounds on atmospheric particulate matters ( PM ) . The TD was operated by direct heating and placed on the GC injector, leading to high heating rate and easy transfer of analytes to GC without focusing of analytes by cold trap. For establishing the TD-GC method, the materials used for supporting PM samples, temperature and time of thermal desorption, and types of sample injection were investigated for detection of sixteen polycyclic aromatic hydrocarbons ( PAHs) and nine n-alkanes. The limits of detection of the proposed TD-GC method were in the range of 0. 014-0. 093 ng for PAHs, and 0. 016-0. 026 ng for n-alkanes, respectively, with the correlation coefficients of correlation above 0. 9975. The TD-GC method was applied to the determination of trace PAHs and n-alkanes on PM10 samples from three cities. The recoveries were in the range of 95%-135% ( PAHs) and 95%-115% ( n-alkanes) , respectively. Finally, the TD was coupled to GC-MS for comparison of the contents of PAHs and n-alkanes on PMx with different particulate size ( x=10 , 5, 2, 1, 0. 5, 0. 25, 0. 1).

Health Effect Assessment on Volunteers Involved in the Cleanup Operation Following the Hebei Spirit Oil Spill Along the Taean Coast, Korea / 대한산업의학회지

OBJECTIVE: The objetive of this study is to assess the level of oxidative stress by the exposure to volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) in volunteers who cleaned up the crude oil spilled from the Hebei Spirit on the Coast of Taean County, Korea. METHODS: The study subjects were 46 volunteers and 37 controls from the National Institute of Environmental Research. A self-administered questionnaire was used for volunteers to examine their working environment and health effects. Urinary concentrations of hippuric acid, 1-hydroxypyrene, and 2-naphthol were measured as exposure markers for VOCs and PAHs, and urinary thiobarbituric acid reactive substances (TBARS) and 8-hydroxydeoxyguanosine (8-OHdG) levels were measured as oxidative stress markers. RESULTS: Sixty-four percent of the respondents presented a variety of symptoms, including sore eyes and throat, nausea, dizziness, headache, low back pain, and leg pain after participating in the cleanup operation. Urinary 2-naphthol and TBARS concentrations appeared higher in the volunteers. Univariate and multivariate analyses showed that urinary TBARS and 8-OHdG levels were positively correlated with urinary 2-naphthol and 1-hydroxypyrene concentrations respectively, especially among the volunteers. CONCLUSIONS: The result implies that participating in cleanup work of oil spills may have a possibility to induce oxidative damage by exposure to PAHs in crude oil.

Combined Toxicity of Volatile Organic Compounds and Ammonia in Indoor Air / 环境与健康杂志

Objective To explore the combined toxicity of dominant volatile organic compounds(VOCs) and ammonia in indoor air of newly decorated rooms.Methods The gaseous mixture of several main components of VOCs and ammonia was prepared using their pure chemical reagents based on the percentage of mass proportion to each pollutant calculated by the medians of concentrations of formaldehyde,benzene,methylbenzene,dimethylbenzene,ethylbenzene and ammonia obtained from the in situ monitoring data on indoor air of 45 newly decorated apartments.The Kunming mice were exposed to the prepared gaseous mixture at doses of 3.93,8.47,18.24 and 39.35 g/m3 for acute toxicity test,and at doses of 3.935 g/m3(higher dose),1.970 g/m3(middle dose)and 0.393 g/m3(lower dose)for sub-acute toxicity test respectively.Results The LC50 of the prepared gaseous mixture was 26.84 g/m3 for Kunming mice.The sub-acute toxicity test showed that the lower levels of reticulocyte count of female mice in each dose group,the lower level of HCT of female mice dose group,the lower levels of PLT in serum of female and male mice in higher dose group,higher activity of ALT in serum of female mice in higher dose group showed significant differences compared with those of controls (P

Chemical Reaction of VOCs in Indoor Air and Health Effects / 环境与健康杂志

Many kinds of volatile organic compounds(VOCs)exist in the indoor air,the chemical reaction will occur among the pollutants when O3 and NO2 exist simultaneously.This reaction can severely impact the indoor air quality and produce some adverse effects on human health.The main chemical reactions among the indoor air pollutants and the potential health effects associated with inhalation exposure to the products of the chemical reaction in the indoor air were discussed in the present paper.The study of the chemical reactions among indoor VOCs is very important for human health and is helpful for revising the Indoor Air Quality Standard and making the 'Ecologic Label' of building materials.

Qualitative Analysis of Organic Pollutants in Indoor Air of Newly Decorated Houses / 环境与健康杂志

Objective To establish a method of adsorption and thermal desorption-GC-MS and to study the component of organic pollutants in indoor air in newly decorated houses. Methods Used Tenax TA as an adsorbent, the qualitative analysis of the indoor air in two typical newly decorated houses had been done with adsorption-thermal desorption GC-MS method. Results More than sixty organic compounds were detected, besides volatile organic compounds such as acetic acid, glycol, toluene and semivolatile organic compounds such as acenaphthene, anthracene, octadecane, monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, fatty hydrocarbons, oxygen contained hydrocarbons and so on were detected. Conclusion This method can be used for the qualitative analysis of pollutants in indoor air. The organic compounds detected in the air of newly decorated houses are complex of different components.

Determination of 13 Kinds of Aldehyde and Ketone Pollutants of Indoor Air by HPLC at One Time / 环境与健康杂志

Objective To establish a method for determination of 13 kinds of aldehyde and ketone pollutants in indoor air by HPLC at one time. Methods The aldehyde and ketone compounds in the air react with 2 4-DNPH and form hydrazone derivatives then determined by HPLC with SPD detection at a flow of CH3CN∶H2O 70∶30 365 nm wavelength. Results 13 kinds of hydrazone were favorably separated the average recovery rates were 96%～101% the lowest detection limits were 0.002～0.02 mg/m3 the linearity range was 0.1～4.0 mg/m3. Conclusion This method can be used for quantitative analysis of 13 kinds of aldehyde or ketone pollutants in indoor air at one time.