• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.242-250
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• 2019

An analytical method was developed for the determination of fenquinotrione, a triketone herbicide, in agricultural products. Fenquinotrione was metabolized to KIH-3653-M-2 in plants. Analyte extraction was conducted using 2% formic acid in acetonitrile and cleaned up using a hydrophillic-lipophillic balance (HLB) cartridge. The limits of detection (LOD) and quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. Matrix-matched calibration curves were linear over the calibration ranges ($0.001{\sim}0.1{\mu}g/mL$) into a blank extract with $r^2>0.99$. The recovery results for fenquinotrione and KIH-3653-M-2 ranged between 81.1 to 116.2% and 78.0 to 110.0% at different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$) with relative standard deviation (RSD) less than 4.6%. All values were corresponded with the criteria ranges requested in both the Codex (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of fenquinotrione in the Republic of Korea.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.389-393
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• 2008

This study examined the effects of cooking temperature and onion (Allium cepa L.) tissue concentrate on heterocyclic amine (HCA) formation in fried ground beef patties. Various amounts of onion tissue (2.0, 5.0, and 10.0%, w/w) were added to the ground beef patties, which were then fried at two different temperatures (190 and $225^{\circ}C$) for 10 min/side. The ground beef patties fried at $190^{\circ}C$ and containing 10.0% (w/w) onion showed a 51% decrease in mutagenicity, and formation of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) was reduced by 58% and 63%, respectively. For the patties fried at $225^{\circ}C$, total mutagenicity decreased by 35% and 48% with the additions of 5.0 and 10.0% (w/w) onion, respectively, and PhIP formation was reduced 50, 60, and 71% with the additions of 2.0, 5.0, and 10.0% (w/w) onion, respectively.

• Korean Journal of Materials Research
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• v.26 no.3
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• pp.117-122
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• 2016

White organic light-emitting diodes with a structure of indium-tin-oxide [ITO]/N,N-diphenyl-N,N-bis-[4-(phenylm-tolvlamino)-phenyl]-biphenyl-4,4-diamine [DNTPD]/[2,3-f:2, 2-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile [HATCN]/1,1-bis(di-4-poly-aminophenyl) cyclo -hexane [TAPC]/emission layers doped with three color dopants/4,7-diphenyl-1,10-phenanthroline [Bphen]/$Cs_2CO_3$/Al were fabricated and evaluated. In the emission layer [EML], N,N-dicarbazolyl-3,5-benzene [mCP] was used as a single host and bis(2-phenyl quinolinato)-acetylacetonate iridium(III) [Ir(pq)2acac]/fac-tris(2-phenylpyridinato) iridium(III) $[Ir(ppy)_3]$/iridium(III) bis[(4,6-di-fluoropheny)-pyridinato-N,C2] picolinate [FIrpic] were used as red/green/blue dopants, respectively. The fabricated devices were divided into five types (D1, D2, D3, D4, D5) according to the structure of the emission layer. The electroluminescence spectra showed three peak emissions at the wavelengths of blue (472~473 nm), green (495~500 nm), and red (589~595 nm). Among the fabricated devices, the device of D1 doped in a mixed fashion with a single emission layer showed the highest values of luminance and quantum efficiency at the given voltage. However, the emission color of D1 was not pure white but orange, with Commission Internationale de L'Eclairage [CIE] coordinates of (x = 0.41~0.45, y = 0.41) depending on the applied voltages. On the other hand, device D5, with a double emission layer of $mCP:[Ir(pq)_2acac(3%)+Ir(ppy)_3(0.5%)]$/mCP:[FIrpic(10%)], showed a nearly pure white color with CIE coordinates of (x = 0.34~0.35, y = 0.35~0.37) under applied voltage in the range of 6~10 V. The luminance and quantum efficiency of D5 were $17,160cd/m^2$ and 3.8% at 10 V, respectively.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.719-725
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• 2009

Heterocyclic aromatic amines (HCAs) are potent mutagens and possible human carcinogens that are formed during the heating of protein-rich foods. The effects of preheating treatment of beef patties using a microwave prior to frying at $220^{\circ}C$ for 10 min on each side on the reduction of HCAs (amino-carbolines and amino-imidazo-azaarenes) were evaluated. The amount of HCAs was then evaluated by solid-phase extraction and high pressure liquid chromatography (HPLC) analysis. The beef patties were treated by microwaving for various times (0, 1, 1.5, 2, or 3 min) before pan-frying. The results revealed the presence of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b] indole (Trp-P-1), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 9H-pyrido[3,4-b]indole (Norharman), 1-methyl-9H-pyrido[3,4-b]indole (Harman), 2-amino-9H-pyrido[2,3-b] indole ($A{\alpha}C$), 2-amino-3,8 dimethylimidazo[4,5-f]-quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) in all samples. However, microwave pretreatment for 1 min inhibited the formation of these HCAs by up to 90% when compared to the control.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.581-586
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• 1998

The present study was conducted to prepare seaweed extracts suppressing mutagenic activity of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine ( PhIP ) ana 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx) derived from cooked meat produce. The tumor initiation activity of PhIP and MeIQx was assayed with Ames method using Salmonella typhimurium TA98 in the presence of S-9 mixtures before and after addition of methanol-solubles of seaweed, such as, Phaeophyta; Undaria pinnatifida, Ecklonia stolonifera Ecklonia cava, Laminaia japonica Sargassum fulvellum, Sargassum hornezi, Sargassum miyabei, Sargassum thunbergii, Agarum cribrosum and Hizikia fusifomis, Rhodophpei Porphyra yezoensis, Grateloupia eiliptiut Lomentraria catenata, Ploemium telfairiae and Glarilaria verrucosa, Chlorophyta; Codium fragile, Enteromorpha compresa and Ulva pertusa. Among seaweed tested, Phaeophyta was shown the higher desmutagenic activity than Rhodophyta and Chlorophyta. E. stolonifera, E. cava and S. miyabei, among Phaeophyta exerted the stronger desmutagenic activity (above $90\%$/2 mg). The ethyl acetate, diethyl ether and chlomform extracts except water extracts from E. stolonifera exhibited a high desmutagenic activity. The ethyl acetate extract of E. stolonifera which showed highest activity was fractionated with Sephadex LH20 column chromatography to give active fraction A-7, which showed desmutagenicity of $90\%$/mg against PhIP and $80\%$/mg against MeIQx. The active fraction had the absorbance at 207.7 and 232nm.

• Analytical Science and Technology
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• v.21 no.3
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• pp.191-200
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• 2008

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aquatic environmental samples. Therefore, it required rapidly and certainly analytical method for pharmaceuticals which are existed in environment. In this study, Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) was used to measure the concentrations of 7 pharmaceuticals (quinoxaline-2-carboxylic acid, acetylsalicylic acid, diclofenac-Na, naproxen, ibuprofen, mefenamic acid, talniflumate) from environmental water or aquatic samples simultaneously. Effective sample clean-up by solid-phase extraction (SPE) prior to LC-MS/MS analysis is necessary. For further purification, Mixed Cation eXchange (MCX) and Hydrophilic-Lipophilic Balance (HLB) solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. LODs (Limits of Detection) and MDLs (Method Detection Limits) for the spiked sample in fresh water were in the range of 0.05~1.50 pg/mL and 0.17~4.90 pg/mL, respectively. The absolute recovery in the concentration of 1.0 ng/mL were between 81.9 and 116.3%. The acidic pharmaceuticals were detected in concentrations of 0.018~16.925 ng/mL in aquatic environmental samples.