• Analytical Science and Technology
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• v.28 no.6
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• pp.385-397
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• 2015

Harmful and potentially harmful constituents (HPHCs) are chemical compounds in tobacco smoke that cause harm to smokers and non-smokers. This study established and validated methods for the analysis of HPHCs from mainstream cigarette smoke. The analyzed HPHCs were categorized into seven groups: aromatic amines, volatile organic compounds (VOCs), heavy metals, tobacco specific nitrosamines (TSNAs), benzo[a]pyrene (B[a]P), ammonia, and carbonyl compounds. The methods were validated by specificity, linearity, limit of detection (LOD), accuracy, precision, and recovery. These validated methods were then applied to the reference cigarettes (1R5F, 3R4F). The correlation coefficients (r²) for the calibration curves of the seven groups were over 0.995. The LODs showed values of 0.01-0.04 ng/cig cig for aromatic amines, 0.01-0.16 μg/cig for VOCs, 0.01-1.27 ng/cig for heavy metals, 0.06-0.28 ng/cig for TSNAs, 0.04 ng/cig for benzo[a]pyrene, 0.08 μg/cig for ammonia, and 0.78-1.77 μg/cig for carbonyl compounds. The precisions obtained from the intra and inter-day batches were less than 15%. The accuracy and the recovery range were less than 15% and 79.2-117.5%, respectively. The proposed methods can therefore be applied for determining HPHCs in tobacco mainstream smoke.

• Analytical Science and Technology
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• v.26 no.4
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• pp.287-297
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• 2013

The optimization of analytical method for the thermal desorption of seven VOCs (volatile organic compounds) by TD-GC/MS (thermal desorption-gas chromatograph-mass spectrometer) with solid phase sorbent tube, and comparative analysis for the determination of VOCs plotted by standard sorbent tubes prepared using both gas phase and liquid phase materials were investigated. The result of paired t-test showed that a liquid phase standard sorbent tube method was in agreement with a gas phase standard sorbent tube method for six species of VOCs including benzene, toluene, ethylbenzene, o-, m-, and p-xylene except for styrene at the significance level (${\alpha}=0.01$), while the 15.6% of difference in response factor between both of gas phase and liquid phase standard plotting for the determination of styrene showed that both methods were significantly different at the significance level. Therefore, the liquid phase standard plotting method was employed to reduce erroneous data for the determination of styrene including BTEX. Under the optimized analytical method by liquid phase standard sorbent tube, recovery was between $100{\pm}5%$ for 7 species of VOCs, reproducibility ranged from 0.3 to 7.7%, and method detection limit (MDL) ranged from $0.01{\mu}g/m^3$ for o-xylene to $0.27{\mu}g/m^3$ for toluene. The optimized standard method was applied to determine VOCs VOCs from indoor air of of dormitory, one bedroom apartment, and a new car.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.390-397
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• 2010

Residual solvents in foods are defined as organic volatile chemicals used or produced in manufacturing of extracts or additives, or functional foods. The solvents are not completely eliminated by practical manufacturing techniques and they also may become contaminated by solvents from packing, transportation or storage in warehouses. Because residual solvents have no nutritional value but may be hazardous to human health, there is a need to remove them from the final products or reduce their amounts to below acceptable levels. The purpose of this study was to develop and evaluate an analytical method for the screening of residual solvents in health functional foods. Furthermore, the aim of this study was to constitute a reasonable management system based on the current state of the market and case studies of foreign countries. Eleven volatile solvents such as MeOH, EtOH, trichloroethylene and hexane were separated depending on their column properties, temp. and time using Gas Chromatography (GC). After determining the GC conditions, a sample preparation method using HSS (Head Space Sampling) was developed. From the results, a method for analyzing residual solvents in health functional foods was developed considering matrix effect and interference from the sample obtained from the solution of solvents-free health functional foods spiked with 11 standards solutions. Validation test using the developed GC/HSS/MS (Mass Spectrometry) method was followed by tests for precision, accuracy, recovery, linearity and adequate sensitivity. Finally, examination of 104 samples grouped in suits was performed by the developed HSS/GC/MS for screening the solvents. The 11 solvents were isolated from health functional foods based on vapor pressure difference, and followed by separation within 15 minutes in a single run. The limt of detection (LOD), limit of quantification (LOQ), recovery and coefficient of variation (C.V.) of these compounds determined by the HSS/GC/MS were found to be 0.1 pg/mL, 0.1-125 pg/g, 51.0-104.6%, and less than 15%, respectively. Using the developed HSS/GC/MS method, residual solvent from 16 out of 104 health functional products were detected as a EtOH. This method therefore seems t o be a valuable extension ofanalytical method for the identification of residual solvents in health functional food.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.345-358
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• 1999

To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58％ of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.

• The Korean Journal of Mycology
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• v.3 no.1
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• pp.21-25
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• 1975

This is a study to determine the content of the mercury compound and the distribution of microorganisms in the waste waters flowing from the chemical plants in the Ulsan area (at 4 stations). The summary of the result of this study is as follows: 1. The content of the mercury compound has ranged from non-detection to 0.075 ppm with an average of 0.03 ppm. The highest content has been detected from the water at station A. 2. As for the distribution of the microorganisms, one species each of bacteria, Mucor, Aspergillus, Cladosporium, and Trichothecium (T. roseum); 4 species of Penicillium; and 3 species of Sterile hyphae; a total of 12 species have been isolated. 3. The following results have been found with regard to the growth of these microorganisms in terms of the content of the mercury compound. In the case of an inorganic mercury compound, most of the microbes can grow in water with a content of up to 10 ppm. Pe. sp No. 1 particularly can grow even in 50 ppm. In the case of an organic mercury compound, the growth of the microbes seems to be somewhat restrained even in 2 ppm.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.387-395
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC-MS/MS) has been developed, allowing the simultaneous multi-analyte determination of 11 synthetic fragrances (SFs) in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 10.9%). The extraction efficiencies were above 83% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~4.1 ng/L and 6.6~12.9 ng/L, respectively. The developed method offers the ability to detect 11 SFs at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 11 SFs. The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.52-59
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• 2014

In general, sulfur containing odorants are added to fuel gases, such as LPG, and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. In this study, sulfur free odorant for low sulfur fuel and prevention of metal corrosion were developed to replace current sulfur containing odorant for gas fuel. They were selected from 12 odorant containing non-sulfur organic compounds and evaluated by odor olfactory method (odor quality, odor intensity). Finally, selected mixture odorants were methyl isovalerate, methyl acrylate, 2-ethyl-3-methyl pyrazine with blending ratio of 50% : 40% : 10%. Final Sulfur free odorant was added 40 wt ppm in LPG fuels and evaluated fuel quality characteristics, metal corrosion test and long term stability of LPG fuel. It were limit in current LPG fuel standard in fuel quality characteristics. Final Sulfur free odorant also had no influence on metal corrosion and long term stability test with 60 days by adding in LPG fuels. Finally, they were shown to be warning agent candidates to reduce sulfur content and metal corrosion for LPG fuel.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Journal of the Korean Chemical Society
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• v.65 no.6
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• pp.433-440
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• 2021

Surfactants are organic compounds that have both hydrophilic and non-polar parts in one molecule, classified as non-ion, anion, cation, and amphoteric surfactants according to the charge of hydrophilic parts in aqueous state. A trace amounts may remain when vegetables and fruits are washed using type1 detergent (Vegetable and fruit detergent), and there is a possibility of exposure to the human body through ingestion. This study developed the simultaneous analysis method for 5 surfactants with LC-MS/MS for analysis of detergent residues after washing vegetables and fruits with detergent. The mobile phase used distilled water and acetonitrile containing 50 mM ammonium formate and 0.1% formic acid and was analyzed using a gradient method using XBridge BEH C8 column. The accuracy of the established method was 83.9-112.1%, and the precision was less than 20%. The detection limit was 7.0 (SLS) to 29.0 (SLES-N3) ㎍/L, and the correlation coefficient (r²) of calibration line regression was greater than 0.99, it is considered suitable for the analysis of trace amounts of surfactant components remaining in vegetables and fruits.