• Analytical Science and Technology
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• v.17 no.2
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• pp.130-144
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• 2004

Recently, the air pollution in A and B industrial area has become one of the most important issues, then 60 VOCs in the area were measured using a highly sensitive method. The VOCs were adsorbed onto Carbotrap using air sampler and subsequently desorbed by a thermal desorber system into gas chromatograph-mass spectrometry (TDS-GC-MS). The peaks of all compounds had good chromatographic properties and offered very sensitive response for the EI-MS (SIM). Method detection limits (MDL) ranged from 0.01 to 0.1 ppt(v/v), and linearities of calibration curves were over 0.995. We analyzed total 90 atmosphere air samples of A and B industrial complex using the method. Benzene, toluene, ethylbenzene, xylene, n-hexane, fluorotrichloromethane, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, styrene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, sec-butylbenzene and naphthalen were identified as the major compounds in the air, and their average concentrations were 0.81, 5.02 1.30, 3.0, 0.81, 37.9, 0.07, 0.15, 0.15, 0.79, 0.06, 0.33, 0.03, 0.12, 0.23, and 0.35 ppb(v/v), respectively. The concentrations of VOCs were low in summer and high in fall or winter. When the concentrations detected in air compare with WHO's norm, no case exceed it.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1244-1250
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• 2000

A method for simultaneous quantitative determination of plasticizers such as diethyl phthalate(DEP), di-n-propyl phthalate(DprP), di-n-butyl phthalate(DBP), di-n-pentyl phthalate(DPP), butylbenzyl phthalate(BBP), di-(2-ethylhexyl) phthalate(DEHP), dicyclohexyl phthalate(DCHP) and di-(2-ethylhexyl) adipate(DEHA), which are suspected as endocrine disruptors, in food was studied. A analysis method was optimized for the quantification of plasticizers in Jjambbong, which is a kind of fatty noodle, by using GC/FID. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 3.5, 5.3, 2.2, 2.2, 7.2, 1.7, 1.9 and 3.0 mg/kg, respectively. Much higher recovery was obtained by extraction with acetone/n-hexane(1:1) rather than hexane solvent system. The recovery of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 72.7, 85.9, 91.4, 97.1, 100.8, 103.2, 104.3 and 95.8% after 4 time extractions, respectively. The migration of plasticizers from PVC wraps into PVC wrap covered Jjambbong was conducted after shaking(120 rpm) for 30min at room temperature with chosen solvent system. It was found that the migration level of DEHA were 577, 706, 770 mg/kg into Jjambbong, respectively, while the other plasticizers were not observed.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.334-339
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• 2019

A procedure based on high-performance liquid chromatography (HPLC) is described to determine ${\beta}-carotene$ in infant formulas. The method for ${\beta}-carotene$ analysis was performed on a C18 reversed-phase column using acetonitrile/methanol/dichloromethane (6:1:3, v/v/v) as a mobile phase. ${\beta}-Carotene$ was determined in HPLC with photo diode array (PDA) detector. The parameters of validation were specificity, linearity, LOD, LOQ, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity ($R^2$), which was over 0.999 in the range of 0.125~2 mg/L. The detection and quantification limits were 0.064 and 0.193 mg/L, respectively. The accuracy and precision of this method using an STD spiked sample were 80~119% and 1.02~2.05% respectively. The method was applied to the analysis of various infant formula and follow-up formulas products containing ${\beta}-carotene$, and all the products contained acceptable levels of ${\beta}-carotene$ for nutrition labeling.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.125-141
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• 2011

Melamine has raised international concerns for its catastrophic health effects from tainted infant formula. This report concerns the developmental validation of a sensitive HPLC/MS/MS and GC/MS methods about melamine and cyanuric acid in human urine and serum. Analytical detection ranges of LC/MS was from 0.2 to 5.0 ng/mL and 2.0 to 60.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 0.2 ng/mL for both analytes in human urine and serum by LC/MS/MS. The range of recovery was 91.6%, and 107.6% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was from 2.0%, to 11.8% for cyanuric acid and melamine in urine. The range of recovery was from 94.9%, to 119.0% about cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.7%, and 13.5% about cyanuric acid and melamine in serum. Analytical detection ranges of GC/MS were 5.0 to 100.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 5.0 ng/mL for both analytes in human urine and serum by GC/MS. The range of recovery was from 83.7%, to 114.5% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was 3.5%, and 10.7% for cyanuric acid and melamine in urine. The range of recovery was 94.4%, and 110.7% for cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.9%, and 13.8% for cyanuric acid and melamine in serum. Several changes were taken to optimize performance by this method.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.1-7
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• 2010

To revise the dithiocarbamates residue analysis method and survey the residues in agricultural products that were treated with these fungicides in Korea, we purchased 20 types of foodstuffs (rice, potato, cabbage, apple etc.) from markets in five major cities. 236 samples of the purchased foodstuffs were then analyzed for the presence of dithiocarbamates by HPLC/UV and HPLC/APCI-MS. The $R^2$, LOD and LOQ in the range of 0.5-107.3 mg/L were as follows: DCC: y=174.34x+18.315, $R^2=0.9999$, 0.01 mg/L, and 0.04 mg/L; EBDC: y=227.38x-14.715, $R^2=1.0000$, 0.01 mg/L and 0.02 mg/L; PBDC: y=38.46x-21.412, $R^2=0.9999$, 0.04 mg/L, and 0.1 mg/L; ETU: y=52.752x-4.4819, $R^2=0.9998$, 0.02 mg/L and 0.03 mg/L; PTU: y=128.28x+4.4624, $R^2=0.9998$, 0.02 mg/L, and 0.04 mg/L. The levels of DDC, EBDC, PBDC, ETU and PTU in 20 agricultural products fortified to 10.0-107.3 mg/L ranged from 61.7-117.5%, 65.3-110.1%, 61.5-109.6%, 69.3-116.3% and 70.2-97.2%, respectively. Overall, dithiocarbamates were detected in 100 samples and the detection ratio was 42.4%. Among these, only 3 samples (1.3%) of Lycii fructus had residue levels that were above the action limits, while the remaining samples (233 samples) contained levels of dithiocarbamates below the detection limit or below the Korea MRLs (Maximum Residue Limits).

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.702-710
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• 2011

The occurrence of aflatoxins $B_1$, $B_2$, $G_1$ and $G_2$ in nuts, their products and dried fruits was investigated. Samples were collected from local markets in Seoul and analyzed by rapid resolution liquid chromatography coupled with tandem mass spectrometry using an immunoaffinity column. The chromatography method was validated for assay of aflatoxins using linearity, accuracy, precision and limit of detection and quantification. The linearity in the concentration ranged from 0.10 to $20{\mu}g/kg$ with $R^2$ > 0.9999. Sample recoveries ranged from 71.1 to 97.2% with relative standard deviations below 4.5% for spiking levels from 1 to $10{\mu}g/kg$. The limits of detection ranged between 0.02 and $0.05{\mu}g/kg$ and the limits of quantification ranged between 0.05 and $0.10{\mu}g/kg$. The levels of aflatoxin $B_1$, $B_2$, $G_1$ and $G_2$ in nuts, their products and dried fruits were $B_1$ 0.10 to $9.94{\mu}g/kg$, $B_2$ 0.08 to $1.54{\mu}g/kg$, $G_1$ 0.04 to $3.21{\mu}g/kg$ and $G_2$ 0.06 to $0.14{\mu}g/kg$.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.63-75
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• 2016

Aquaculture has historically delivered marine products because the country is surrounded by ocean on three sides. Surveys on production have been conducted recently to systematically manage aquaculture facilities. Based on survey results, pricing controls on marine products has been implemented to stabilize local fishery resources and to ensure minimum income for fishermen. Such surveys on aquaculture facilities depend on manual digitization of aerial photographs each year. These surveys that incorporate manual digitization using high-resolution aerial photographs can accurately evaluate aquaculture with the knowledge of experts, who are aware of each aquaculture facility's characteristics and deployment of those facilities. However, using aerial photographs has monetary and time limitations for monitoring aquaculture resources with different life cycles, and also requires a number of experts. Therefore, in this study, we investigated an automatic prototype system for detecting boundary information and monitoring aquaculture facilities based on satellite images. KOMPSAT-3 (13 Scene), a local high-resolution satellite provided the satellite imagery collected between October and April, a time period in which many aquaculture facilities were operating. The ANN classification method was used for automatic detecting such as cage, longline and buoy type. Furthermore, shape files were generated using a digitizing image processing method that incorporates polygon generation techniques. In this study, our newly developed prototype method detected aquaculture facilities at a rate of 93%. The suggested method overcomes the limits of existing monitoring method using aerial photographs, but also assists experts in detecting aquaculture facilities. Aquaculture facility detection systems must be developed in the future through application of image processing techniques and classification of aquaculture facilities. Such systems will assist in related decision-making through aquaculture facility monitoring.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.945-951
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• 1999

A simple and practical method for the determination of gardenia yellow in foods was developed. In this method, analysis of gardenia yellow in food products has been carried out by the detection of crocetin and/or geniposide as indicator compounds. As a new analytical method for gardenia yellow, we adopted crocetin, which is produced from colored components of gardenia yellow by alkaline hydrolysis, as an indicator compound. The analysis of gardenia yellow was performed by reverse phase high performance liquid chromatography using a Capcell pak $C_{18}$ column at wave length 240 nm (geniposide) and 435 nm (crocetin). The recovery rates of geniposide and crocetin were found to be 93.4% and 87.8% for Dan Mu Ji, 90.2% and 85.9% for milk, 92.8% and 86.5% for snack, respectively. With this method, the range of crocetin and geniposide contents $({\mu}g/g)$ were as follows: $ND{\sim}1.7$ and $ND{\sim}14.1$ for Dan Mu Ji, $ND{\sim}0.2$ and $ND{\sim}13.6$ for milk, $ND{\sim}1.6$ and $ND{\sim}0.9$ for snack, respectively. The detection limits of crocetin and geniposide were 0.07 ${\mu}g/g$ and 0.05 ${\mu}g/g$, respectively.

• Analytical Science and Technology
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• v.15 no.5
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• pp.417-426
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• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.266-271
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• 2018

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for health-functional foods (dietary food supplements) to establish regulatory standards and specifications in Korea. In this regard, we continue our research on developing analytical methods for the items. Octacosanol is the major component of polycosanol and is a high-molecular-mass primary fatty alcohol, obtained from sugar cane wax. Previous researchers have shown that octacosanol can lower cholesterol and has antiaggregatory properties, cytoprotective uses, and ergogenic properties for human health. Recently, octacosanol products have been actively introduced into the domestic market because of their functional biological activity. We have developed a sensitive and selective test method for octacosanol that the TMS derivatives by means of gas-chromatographic-tandem mass spectrometry (GC-MS). The trimethylsilyl ether derivative of the target analyte showed excellent chromatographic properties. The procedure was validated in the range of $12.5{\sim}200{\mu}g/L$. Standard calibration curves presented linearity with the correlation coefficient ($r^2$) > 0.999, and the limits of detection (LOD) and limits of quantitation (LOQ) were $4.5{\mu}g/L$ and $13.8{\mu}g/L$, respectively. The high recoveries (92.5 to 108.8%) and precision (1.8 to 2.4%) obtained are in accordance with the established validation criteria. Our research can provide scientific evidence to amend the octacosanol test method for the Health-Functional Food Code.