• Korean Journal of Food Science and Technology
• /
• v.45 no.4
• /
• pp.391-402
• /
• 2013

Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.

• Korean Journal of Food Science and Technology
• /
• v.40 no.1
• /
• pp.8-14
• /
• 2008

This study was performed to establish analysis methods, and evaluated for grayanotoxin in domestic/foreign honey and wild honey. The molecular weight of grayanotoxins I, II and III, excluding grayanotoxin III that has been commercialized, were analyzed by LC-MS/MS. Then, the molecular structure of grayanotoxins I and II were analyzed by NMR. A total 111 samples (25 Korean honey, 21 Korean wild honey, 13 Korean honeycomb honey, 44 foreign honey, 8 foreign wild honey) were examined to determined whether or not each sample contained grayanotoxins I, II, and III. The honey samples were mixed with methanol and loaded into a tC18 cartridge, the filtrate was diluted with water, and the mixture was then analyzed by ESI triple-quadrupole LC-MS/MS. Grayanotoxins were only found in the foreign wild honey and were not detected in Korean honey, Korean honeycomb honey, or Korean wild honey. Three of the samples contained grayanotoxin I, II, and III, and one sample contained only grayanotoxins I and III. The lowest level for grayanotoxin I was 3.13 ${\pm}$ 0.00 mg/kg, and the highest level was 12.93 ${\pm}$ 0.01 mg/kg. The levels of grayanotoxin II were 0.84 ${\pm}$ 0.01 mg/kg, 0.92 ${\pm}$ 0.00 mg/kg and 1.08 ${\pm}$ 0.01 mg/kg, respectively. The lowest level of grayanotoxin III was 0.25 ${\pm}$ 0.01 mg/kg and the highest level was 3.29 ${\pm}$ 0.74 mg/kg. Through this study, safety management for foreign wild honey has been enabled.

• Korean Journal of Food Science and Technology
• /
• v.32 no.3
• /
• pp.544-549
• /
• 2000

This study was performed to compare optimum analytical method for the contents of naturally occurring sulfur dioxide in foods and to investigate the contents of sulfur dioxide in foods in order to provide a fundamental data when distinguish between added and naturally occurring sulfur dioxide. The determination of the contents of sulfur dioxide in foods from the 20 kinds, 180 cases of samples has been analyzed by the optimized Monier-Williams method, modified Rankine method and Acid Distillation/Ion Chromatography. As a result of the study, the contents of naturally occurring sulfur dioxide in foods by the optimized Monier-Williams method showed from 1.02 to 43.87 ppm and highly content of 43.87, 15.37, 11.50, 11.21 and 10.60ppm were observed in garlic, platicodon, green onion, cabbage and onion, the others were less than 10.00ppm. The sulfur dioxide contents in green onion and garlic by modified Rankine method were showed to be 2.87 and 6.14ppm, respectively, the others were detected less than 2.50ppm. The contents of sulfur dioxide by Acid Distillation/Ion Chromatography showed 15.43, 9.82, 5.74, 5.37, 2.14 and 0.49ppm in garlic, cabbage, green onion, onion, potato and apple, respectively and the others were not detected. And the contents of sulfur dioxide in green onion, onion, cabbage and garlic showed higher levels of sulfur dioxide in these foods than the others because of the naturally occurring sulfur containing compounds. The optimized Monier-Williams method, which is the of official analytical method of Korean Food Code, was suitable for monitoring of sulfur dioxide of most foods. Acid Distillation/Ion Chromatography was thought to be adequate for sulfur containing foods such as green onion, onion and cabbage. In order to distinguish between added and naturally occurring sulfur dioxide, it is though to be need of the fundamental data for the contents of sulfur dioxide in sulfite-free foods and continue the investigation for it.

• Clean Technology
• /
• v.17 no.4
• /
• pp.379-388
• /
• 2011

The purpose of this study was to investigate the concentration levels, distribution characteristics and blood concentration of Polycyclic Aromatic Hydrocarbons (PAHs) at ambient air in Industrial Complex Area. The samples were collected at 4 sites in Industrial Complex Area and its vicinities. The result indicated that there was the difference of PAHs concentration as followed local characteristics. The level of average concentration of PAHs in the air in Industrial Complex Area was $14.52{\sim}193.48ng/m^3$. The level of average concentration of six materials with possibility of cancer creation was $1.65{\sim}13.44ng/m^3$. The concentrations of PAHs were generally low, but Jechul-dong is considered an area where consistent monitoring of PAHs is required. In addition, benzo(a)pyrene was detected in every atmospheric sample, however the concentration was not high. The level of concentration of benzo(a)pyrene in the air in the Jechul-dong was $2.89ng/m^3$. But, the concentration of the PAHs in Jechul-dong showed that the Benzo(a)pyrene concentration is above $1ng/m^3$ of air quality standard(EU). The results of the concentration level of PAHs in the blood from 240 persons who were exposed directly were surveyed, it was $1.12{\sim}11.45ng/m^3$ for man and $1.20{\sim}26.89ng/m^3$ for woman. It was indicated that the difference between the genders was very little. The accumulation inside human was anticipated as the PAHs concentration in the blood for the aged was very high. Industrial Complex Area and its vicinities are an area which has been greatly influenced by PAHs and environmental contaminants. It is necessary to control the emission sources of PAHs and to construct an observation system at Industrial Complex Area from now on. It is time to reduce the risk factors for health and environmental disease to protect the health of resident in Industrial Complex Area and its vicinities.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.882-888
• /
• 2005

Procedure for analysis of methylmercury in fish was developed, involving addition of HCl, extraction with toluene, and clean-up using L-cystein solution. Obtained extract is analyzed by gas chromatography with electron capture detector using Ulbon HR-Thermon-Hg column. Detection limit and recovery of the method were 0.005mg/kg (expressed as Hg), 98-107 (103%), respectively. Total mercury and methylmercury concentrations in 175 commercial fish samples ranged from [mean-max (mean), unit: mg/kg]: 0.014-1.200 (0.270) and 0.006-0.901 (0.168) in tuna-fish, 0.020-0.934 (0.323) and 0.012-0.553 (0.149) in martin-fish, 0.082-0.782 (0.391) and 0.040-0.436(0.201) in shark, 0,023-0.031 (0.026) and 0,013-0.018 (0.015) in salmon, 0.098-0.193 (0.133) and 0.031-0.015(0.090) in tilefish, and 0,031-0.214 (0.089) and 0.016-0.093 (0.042) in canned tuna respectively. No sample of analyzed fish exceeded 1.0mg/kg wet wt., limit for methylmercury established by Codex. In all species examined, estimated weekly intake was lower than Provisional Tolerable Weekly Intake recommended by the JECFA (the Joint FAO/WHO Expert Committee on Food Additives).

• Korean Journal of Food Science and Technology
• /
• v.44 no.1
• /
• pp.21-27
• /
• 2012

This research was carried out as a survey on the contents of lead, cadmium, and arsenic in processed foods (milk, vegetable oil, and margarine) in Korea. The limits of quantification (LOQs) were Pb 0.3 ${\mu}g/kg$, Cd 0.15 ${\mu}g/kg$, and As 0.45 ${\mu}g/kg$ for milk and Pb 0.61 ${\mu}g/kg$, Cd 0.31 ${\mu}g/kg$, and As 0.91 ${\mu}g/kg$ for vegetable oil and margarine. The recoveries were 92.6-98.0% for Pb, 91.2-98.9% for Cd, and 97.9-104.7% for As. The average levels of Pb were 2.395 ${\mu}g/kg$ for milk, and 7.656 ${\mu}g/kg$ for vegetable oil. The average levels of Cd were 0.483 ${\mu}g/kg$ for milk, and 0.380 ${\mu}g/kg$ for vegetable oil, and levels of As were 0.781 ${\mu}g/kg$ for milk, and 1.241 ${\mu}g/kg$ for vegetable oil. The results of this study showed that Pb, Cd, and As contents in the whole samples were less than the maximum residual levels in the processed foods that were specified by the Codex standard.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.11S
• /
• pp.3651-3667
• /
• 2000

Recently, in the distributed multimedia environments based on internet, as radical growing technologies, the most of researchers focus on both streaming technology and distributed object thchnology, Specially, the studies which are tried to integrate the streaming services on the distributed object technology have been progressing. These technologies are applied to various stream service mamgements and protocols. However, the stream service management mexlels which are being proposed by the existing researches are insufficient for suporting the QoS of stream services. Besides, the existing models have the problems that cannot support the extensibility and the reusability, when the QoS-reiatedfunctions are being developed as a sub-module which is suited on the specific-purpose application services. For solving these problems, in this paper. we suggested a QoS Integrated platform which can extend and reuse using the distributed object technologies, and guarantee the QoS of the stream services. A structure of platform we suggested consists of three components such as User Control Module(UCM), QoS Management Module(QoSM) and Stream Object. Stream Object has Send/Receive operations for transmitting the RTP packets over TCP/IP. User Control ModuleI(UCM) controls Stream Objects via the COREA service objects. QoS Management Modulel(QoSM) has the functions which maintain the QoS of stream service between the UCMs in client and server. As QoS control methexlologies, procedures of resource monitoring, negotiation, and resource adaptation are executed via the interactions among these comiXments mentioned above. For constmcting this QoS integrated platform, we first implemented the modules mentioned above independently, and then, used IDL for defining interfaces among these mexlules so that can support platform independence, interoperability and portability base on COREA. This platform is constructed using OrbixWeb 3.1c following CORBA specification on Solaris 2.5/2.7, Java language, Java, Java Media Framework API 2.0, Mini-SQL1.0.16 and multimedia equipments. As results for verifying this platform functionally, we showed executing results of each module we mentioned above, and a numerical data obtained from QoS control procedures on client and server's GUI, while stream service is executing on our platform.

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.525-528
• /
• 2001

This study was conducted to estimate the contents of heavy metals in some health foods available on Korean markets. The samples were digested with microwave system, then analyzed using GF-AAS for the contents of lead (Pb), cadmium (Cd) and arsenic (As). The contents of mercury (Hg) were determined using a mercury analyzer. The average values of Hg, Pb, Cd and As in calcium (Ca) health foods were 0.007, 1.08, 0.02 and 0.48 mg/kg respectively. Those values in chitosan health foods were 0.001, 0.36, 0.01 and 0.03 mg/kg respectively. Those values in propolis health foods were 0.013, 4.96, 0.01 and 0.13 mg/kg, respectively. The health foods that contained cow bone powders had the highest lead contents. Based on the variation in lead contents of those products, it could be possible that they might be contaminated through raw materials and/or manufacuring process. Some propolis products were also very high in lead contents. There could be risks for some population, especially the aged who overtake those health foods, to have heavy intake of lead. Therefore, we established the lead standards of 3.0, 2.0 and 5.0mg/kg less than for Ca, chitosan and propolis health foods respectively, based on the Codex method.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.5
• /
• pp.336-340
• /
• 2009

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October were investigated at Taean in 2007. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. The ion balance between cations and anions values showed high correlation. The mean values of pH and EC were 4.9 and $32.9{\mu}S\;cm^{-1}$, respectively. The EC of rainwater showed seasonal characteristic, which was $91.4{\mu}S\;cm^{-1}$ with relatively low rainfall compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$ > $Ca^{2+}$ > $H^{+}$ > $Mg^{2+}$ > $K^+$. Among these ions, $Na^{+}$ and $NH_4{^+}$ covered over 70% of total cations. In the case of anion, the order was $SO_4{^{2-}}$ > $NO_3{^-}$ > $Cl^{-}$. The mean value of sulfate, which is main anion component in the samples was $152.1{\mu}eq\;L^{-1}$. Also, 90% of soluble sulfate in rainwater was $nss-SO_4{^{2-}}$(non-sea salt sulfate). With fractional acidity and theoretical acidity of rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly in neutralizing the rain acidity.

• Journal of Environmental Impact Assessment
• /
• v.27 no.6
• /
• pp.685-694
• /
• 2018

We measured ecological niche space (ENS) using carbon and nitrogen stable isotope ratios of benthic macroinvertebrates to estimate its applicability for large river assessment. In particular, we compared ENSs of selected macroinvertebrates between upper and lower area of Seungchon Weir in Yeongsan River to estimate the impact of weir on biological community. We also measured basic water quality and community indices including benthic macroinvertebrates index (BMI) to estimate their correlations with calculated ENS. ENS was calculated using the Bayesian Stable Isotope in R statistics (package "SIBER"). The results showed that seasonal variations in water quality and community indices were found, but there was no apparent tendency between upper and lower area of the Seungchon Weir in June (before rainy season) and August (after rainy season). However, ENS of benthic macroinvertebrates markedly decreased across the weir in both June and August regardless of changes in water quality. This means the physical change of the stream due to the weir cause decrease of ecological isotopic niche space of benthic macroinvertebrates regardless of water quality, suggesting physical modification by the weir can affect the interaction between habitat condition and macroinvertebrates. Therefore, the ecological isotopic niche space can be a useful supplementary indicator for the river ecosystem assessment.