• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.181-188
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• 2001

A gas chromatographic method was established for the simultaneous determination of urinary nicotine and cotinine. The analytes in basified urine containing a sufficient amount of Na$_2$S0$_4$were extracted into dichloromethane by vigorous shaking. Into the transferred organic phase was added a small amount of acidified methanol (0.5 N HCI in methanol), followed by concentrating the mixture to dryness using a mild stream of nitrogen gas. The concentrate was reconstituted with methanol and the final solution analyzed using the gas chromatograph equipped with the nitrogen-phosphorus detector. The reproducibility tests showed coefficients of variation less than 11％ for both compounds. The percent recovery for both analytes ranged from 88 to 103％. The estimated method detection limits for nicotine and cotinine were 0.60 and 5.1 ng/mL, respectively. Extraction efficiencies for both nicotine and cotinine apparently declined without the addition of Na$_2$S0$_4$into the urine. Moreover, the absence of methanolic HCI in the extract resulted in almost complete evaporation of nicotine and partial loss of cotinine during the concentration process, indicating that the formation of nicotine-HCI and cotinine-HCI species is prerequisite to the suppression of the loss of both compounds.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.90-95
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• 2009

This study investigates the oxidative degradation of N-nitrosodimethylamine (NDMA), a probable human carcinogen, by advanced oxidation process (i.e., UV process). The experiments were performed with various pH, initial concentration, UV intensity, and addition of $H_2O_2$ or $TiO_2$ on UV process. The results showed that the direct UV photolysis was the most effective treatment method. The lower pH, intial concentration and higher intensity of UV stimulated higher NDMA removal. However, addition of oxidant ($H_2O_2$, $TiO_2$) slows down photochemical treatment of NDMA since the oxidant can filter out the UV light and block it to reach the NDMA molecules. Dimethylamine (DMA) and nitrite were found to be a major byproduct from NDMA oxidation. To evaluate the chronic toxicity effects of UV-treated NDMA on the growth of microalgae, "Skeletonema costatum", was studied as long term experiments. Results demonstrated that after the 13 days exposure the chronic toxicity was decreased about 15% with application of UV process on NDMA degradation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.81-85
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• 2002

The possibility of simultaneous analysis of 24 pesticides out of 30 residual pesticides which are subjected to test in the golf courses was examined. The utility of the simultaneous analysis of multi-residue pesticides was evaluated by recovery test through a standard addition method of pesticides in water, soil, and lawn grass. The experimental results of the recovery rates for individual pesticides are as follows : The number of pesticide of which average recovery was over 70% regardless of medium was 16 pesticides. These pesticides were composed of 8 organophosphorus pesticides(Chlorpyrifos, Chlorpyrifos-methyl, Diazinon, EPN, Fenitrothion, Phenthoate, Phosalone, and Toclofos-methyl). 4 organochlorinated pesticides(Daconil, Captan, Endosulfan, and Tetradifon), 2 pyrethroid pesticides(Fepropathrin, Lambda-cyhalothrin) and 2 other pesticides(Bromopropylate, Pendimethalin). On the other hand, in case of Dicofol, average recovery by medium was over 70% for water and lawn grass but was only 53.3% for soil. Therefore, the simultaneous analytical method applied in this experiment is not appropriate for analysis of Dicofol in soil. Furthermore, among 7 pesticides, 2 pesticides(Amitraz and Pyraclofos) showed that theirs average recovery rates deviated from criteria(70~130%) at almost all media, while 5 pesticides(Bensulide, Deltamethrin, Iprodione, Phosphamidon and Tralomethlin) were not detected from all media by selected GC detector(NPD or ECD).

• Analytical Science and Technology
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• v.8 no.4
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• pp.895-900
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• 1995

Urinary free and acetylated polyamine profiles have been investigated for their potential usefulness as biochemical markers of cancer in a control of group comprised of healthy volunteers (32 cases) and patients with various types of cancers(48 cases). The nine (5 free and 4 acetylated) endogeneous polyamines were simultaneously determined by a sensitive capillary gas chromatography/nitrogen-phosphorus detector (GC/NPD). The newly modified (simple and convenient) method was developed and the compounds were isolated by adsorption onto silica gel and derivatized by heptafluorobutyric anhydride to enhance their specificity on gas chromatograms. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 48.6 ~ 101.2 %. The Korean reference values of urinary polyamines were established and significant differences were found in cancer patients compared with normal subjects. Also, to eliminate subject variations, precursors to product concentration ratios were compared between cancer patients and control group. The ratios of both putrescine to spermidine and total (free plus acetylated) putrescine to total spermidine were significantly greater in cancer patients than in normal subjects.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.471-474
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• 2009

Formaldehyde (FA) is a carcinogenic compound present in cigarette smoke. In this study, the amount of formaldehyde was analyzed in 5 kinds of cigarettes and the inhibitory effect of plant volatile extracts on the formation of FA was investigated. After extraction of the cigarette sample, FA was converted into its thiazolidine derivatives by reaction with cysteamine, and then measured using a gas chromatography-nitrogen phosphorus detector (GC-NPD). The concentrations of FA in cigarette smoke were found between 138.24 and $217.82{\mu}mol/g$ cigarette smoke. Extracts isolated from Welsh onion (Allium cepa L.), garlic (Allium sativum L.), crown daisy (Chrylsanthemum coronarium L.), green pepper (Capsicum annuum L.), and sesame dropwort (Oenanthe javanica DC) were used for analyzing their inhibitory effects on the formation of FA. The inhibitory effects of extracts of Welsh onion, garlic, crown daisy, green pepper, and sesame dropwort on the formation of FA were 64, 47, 38, 47, and 19%, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.40-45
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• 1997

This study was conducted to evaluate the personal effects of tobacco smoke and environmental tobacco smoke(ETS) by measuring the concentration of nicotine and cotinine in the urine. While 129 urine samples were being collected, Personal characteristics such as sex, age, number of years since a Person has been a smoker, average consumption number of cigarettes per day, and number of smoker in family were also surveyed. Collected urine samples were used for analysis of nicotine and cotinine by GC/NPD after Passing the extrelut column. In the urine of the smoker, the average contents of nicotine and cotinine were 5.38$\mu\textrm{g}$/ml and 3.14 $\mu\textrm{g}$/ml, respectively. The average contents of nicotine and cotinine were 0.18$\mu\textrm{g}$/ml and 0.07$\mu\textrm{g}$/ml in the urine of male non-smoker, respectively. The contents of nicotine and cotinine in the non-smoker's urine were dependent on sex and age. On the other hand, the contents of nicotine and cotinine in smoker's urine were dependent on average consumption amount of cigarettes per day. Also, there was a direct relation between nicotine levels in the smoker's urine and the average consumption number of cigarettes Per day of smoker. The Possible sources of nicotine and cotinine in the non-smoker's urine seemed to be caused by food, beverage and En, Our results indicate that the number of smoker in family had no effect on increasing nicotine and cotinine contents in the urine of non-smoker.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.1-5
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• 2013

This study was conducted to the amount of pesticide residue in 21 different kinds of 100 commercial flowering teas. Multi-residue analyses of 203 pesticides was performed using the GC-ECD, GC-NPD, GC-MSD, and LC-MS/MS. Pesticide residues were detected in 4 samples (4%) of which 4 samples (4%) violated the maximum residue limits. 4 samples violating the limit were all imported teas. Pesticides detected were chlorpyrifos, flufenoxuron, lufenuron, pyrimethanil and methoxyfenozide. These results indicate the need of continuous monitoring of pesticide residue needs for safety of flowering teas.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.100-106
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• 2011

This study was conducted to investigate the residue amount of harmful materials on the 113 commercial fruit teas (Gugija, Omija, Sansuyu) in Gwangju area. It was performed using the GC-ECD, GC-NPD, GC-MSD and the LC-UVD, LC-FLD, LC-MSD to analyze 200 pesticides. The heavy metals were determined using a Mercury analyzer and AAS. The sulfur dioxides were analyzed by modified Monnier-Williams method. The residual pesticides were detected in 4 samples (Gugija). The mean values of heavy metal contents (mg/kg) were Pb, 0.024; Cd, 0.031; As, 0.010; Hg, 0.003. The measured values of Pb, Cd, As, Hg showed within MRLs. The sulfur dioxides were over MRLs in 4 samples (Gugija). These results will be used to establish on the regulation of commercial fruit teas in Gwangju area.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.83-90
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• 2010

This study was conducted to investigate the residue amount of harmful materials on the 153 commercial medical herbs in Gwangju area. It was performed using the GC-ECD, GC-NPD, GC-MSD and the LC-UVD, LC-FLD, LC-MSD to analyze 200 pesticides. The heavy metals were determined using a Mercury analyzer and AAS. The sulfur dioxides were analyzed by modified Monnier-Williams method. The residual pesticides were detected in 7 samples, and were over MRLs (Maximum Risk Levels) in 2 samples (1.3%). The mean values of heavy metal contents (mg/kg) were Pb, 0.570; Cd, 0.081; As, 0.082; Hg, 0.0093. The measured values of Pb, As, Hg showed within MRLs. The excess samples of MRLs were 3 samples (changchul 2, cheongung 1) on Cd. The sulfur dioxides were over MRLs in 7 samples (4.6%), hwanggi and gugija. These results will be used to establish on the regulation of commercial medical herbs in Gwangju area.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.304-307
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• 2005

Multiresidue method was set up for the simultaneous determination of various residual pesticides in potatoes and carrots, which was analyzed by gas chromatography-electron capture detector/nitrogen phosphorus detector. Method consisted with acetone/acetonitrile (9 : 1) extraction and dichloromethane partition, followed by florisil cartridge purification with hexane/dichloromethane/acetonitrile (50 : 45 ; 5) elution. Among 197 pesticides (194 kinds) spiked to food materials, 143 and 155 pesticides were recovered over 70% on potatoes and carrots, respectively. Nineteen pesticides including bromacil, cyproconazole, were not detected in water and sample matrices. Matrix components may affect the low detections of 25 pesticides such as benfuracarb, bitertanol from potatoes and 16 pesticides such as bitertanol, carbosulfan from Carrots. Some pesticides including dichlobenil, fluoroimide and iprodione were highly detected from one or both matrices even though they were not detected from water.