• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.296-313
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• 2014

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) multiresidue method was developed for the simultaneous analysis of 124 pesticides in soil by LC-MS. The procedure involved liquid extraction of soil immersed with 0.2N $NH_4Cl$ by acetonitrile with 1% acetic acid, followed by anhydrous $MgSO_4$ and sodium acetate, and dispersive SPE cleanup with $MgSO_4$, primary secondary amine (PSA) and $C_{18}$. The extracts were analyzed with LC-MS/MS in ESI positive mode. Standard calibration curves were made by matrix matched standards and their correlation coefficients were higher than 0.99. Recovery studies for the validation were carried out using two type soils, loam and sandy loam, at four concentration levels (0.005, 0.01, 0.02, and 0.1 mg/kg). The recoveries of pesticides were in the range of 70-120% with < 20% RSD except 4 pesticides, Benfuracarb, Ethiofencarb, Pymetrozine, and Pyrethrin. This result indicated that the method using QuEChERS and LC-MS/MS could be applied for the simultaneous determination of pesticide residues in soils.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1779-1784
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• 2009

Establishment of simultaneous analysis method and monitoring for individually analyzing residual eight ergosterol biosynthesis inhibitors, EBI (difenoconazole, diniconazole, fenarimol, fenbuconazole, hexaconazole, myclobutanil, nuarimol and paclobutrazol) pesticides in commercial agricultural products, were conducted. The simultaneous analysis method for the pesticides was established using a GC/MS/MS for EBI pesticides. Residual amount of those pesticides were investigated in 989 commercial agricultural products (fifteen kinds of cereal grains, vegetables, beans, nuts, fruits and mushrooms) from seven metropolitan cities and eight provinces. In EBI pesticides analysis, linearity of GC/MS/MS analysis was 0.9974-0.9992, and that of recoveries were 86-135% with relative standard deviations (RSD) <20%. The limit of quantification (LOQ) of the method ranged from 0.5 to 5.0 mg/kg for eight EBI pesticides. According to the monitoring of the EBI pesticides in commercial agricultural products, difenoconazole, fenarimol, hexaconazole showed various residual levels (total frequency of 8/989 detection, 0.8%). Paclobutrazole showed in excess levels of the MRLs (maximum residue limits) for pesticides in one chard sample by the Korea Food Code. As a result of exposure assessment on the detected 8 individual pesticides, all pesticides (difenoconazole, fenarimol, hexaconazole, paclobutrazole) were evaluated as safe level in comparison to toxicologically acceptable daily intake.

• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.115-125
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• 2009

Simultaneous equation models, which are widely used in business and economic areas, generally consist of endogenous variables determined within models and exogenous variables externally determined and in the simultaneous equations model framework there are rank and order conditions for the model identification and the existence of unique solutions. By contrast, their estimating results have less efficiencies and furthermore do not exist, since the most estimating procedures are performed under the assumptions for rank and order conditions. We propose the new statistical test for sufficiency of the rank condition under the order condition, and show the asymptotic properties for the test. The Monte Carlo simulation studies are achieved in order to evaluate its power and to suggest the baseline for satisfying the rank conditions.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.1
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• pp.37-47
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• 2011

Objectives : Previous studies have shown that Fructus mume (FM) has anti-platelet effects. The present study was performed to determine the acute oral toxicity and quality control of a crude extract of FM in ICR mice. Methods : We investigated the in vivo single dose acute toxicity of FM 95% ethanol extract. This test was orally administered once by gavage to 20 male and 20 female mice at dose levels of 0 (control group), 1250, 2500 and 5000mg/kg body weight, respectively. Mortalities, clinical findings, autopsy findings and body weight changes were monitored daily for the 14 days following the administration. HPLC analysis was performed for the simultaneous determination of ursolic acid and p-hydroxycinnamic acid in FM. Reverse-phase chromatography using a C18 column and photodiode array detection at 211 nm was used for quantification of the two maker components. The mobile phase for gradient elution consists of water and acetonitrile. Results : We observed survival rates, general toxicity, change of body weight, and autopsy. The mice did not die after single oral administration of maximum dose of FM. Autopsy of animal revealed no abnormal gross finding. Therefore, $LD_{50}$ value of FM for ICR mice was more than 5000mg/kg on oral route. The HPLC analysis showed that ursolic acid and p-hydroxycinnamic acid amounts to 9.75- and 0.12% in the extract with the retention times of 47.99- and 15.38 minutes, respectively. Conclusions : These results suggest that no toxic dose level of FM in mice is considered to be more than 5000mg/kg. Consequently, it was concluded that FM have no effect on acute toxicity and side effect in ICR mice. For the quality control of FM extract, simultaneous determination of ursolic acid and p-hydroxycinnamic acid was established.

• Journal of Nutrition and Health
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• v.32 no.5
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• pp.533-539
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• 1999

The effects of capsaicin, a pungent principle of hot red pepper, on body fat gain, balance serum lipid values were investigated in rats fed a high-fat(30%) diet. Administration of capsaicin by dietary administration caused a complete cessation of increased in body weight and fat gain induced by the high-fat diet. However, energy intake and body protein gain were not affected by capsaicin. Therefore, the suppression of body fat gain by capsaicn was believed due to an increased in energy expenditure. Simultaneous administration of capsaicin and a $\beta$-adrenergic blocker, propranolo, resulted in the inhibition of changes in body fat gain by capsaicin without remained unchanged, indicating an increase in the number of mitochondria in brown adipose tissue. Therefore, it appears that capsaicin possesses potent body fat suppressive effects mediated by $\beta$-adrenergic stimulation in which brown adipose tissue may be involved. On the other hand, capsaicin had no effects on serum triglyceride, total cholesterol or HDL-cholesterol levels. These results are in contrast to those reported by other investigators. Perhaps expression of the effects of capsaicin on plasma lipids is a rather complicated process, dependent on the type of diet administered, fat content of the diet, period and route of capsaicin administration, and species and strain of animals used.

• Research in Plant Disease
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• v.26 no.4
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• pp.264-271
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• 2020

We have developed a simultaneous diagnostic method that can identify both the species of thrips and tomato spotted wilt virus (TSWV) that are problematic in chrysanthemum plants. This is a method of amplifying DNA by performing reverse transcription-polymerase chain reaction by simultaneously adding primers specific to TSWV coat protein (N) gene and primers specific to the internal transcribed spacer 2 region of Frankliniella occidentalis and F. intonsa using total nucleic acid extracted from one thrips. The sizes of DNA fragments for TSWV, F. occidentalis, and F. intonsa were 777, 287, and 367 bp, respectively. These results showed species identification of thrips and whether thrips carrying TSWV can be simultaneously confirmed. Further usefulness of the simultaneous diagnostic method was made from greenhouse survey at chrysanthemum greenhouses in Taean (Chungcheongnam-do) and Changwon (Gyeongsangnam-do) to investigate the identification of thrips species and the rate of thrips carrying TSWV. Of thrips collected from the greenhouses, 83.7% thrips was F. occidentalis and 72.9% F. occidentalis carried TSWV in Taean. Similarly, the diagnostic method showed that 92.2% thrips was F. occidentalis and 84.0% F. occidentalis carried TSWV in Changwon. These results confirm that F. occidentalis is a dominant thrips species and the thrips species plays a crucial role in the transmission of TSWV in chrysanthemum plants in the greenhouses. Taken together, this study showed a simple diagnostic method for thrips identification and epidemiological studies of the timing and spread of TSWV through thrips in chrysanthemum greenhouses in South Korea.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.127-131
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• 1995

A patient who showed atypical orofacial pain after an endodontic treatment for a long time, was treated with non-analgesics such as vitamin $B_1, B_2, $ and Oral Balance, moisturizing gel. 1. It is important to manage xerostomic condition properly in the treatment of patients who have atypical orofacial pain 2. Simultaneous administration of vitamin $B_1 and B_2$ was effective in increasing pain threshold of the patient.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.4
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• pp.43-46
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• 1982

The purpose of this paper was to study the effect of surfactants on the absorption and the bioavailability of ascorbic acid in the small intestine of rats and rabbits absorption of ascorbic acid in small intestine of rats was increased with tween 80 and span 80.The blood level of ascorbic acid in rabbits was elevated by combined with low concentration of surfactants but high concentration of surfactants. The bioavailability of ascorbic acid was increased by simultaneous administration of surfactants.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.195-201
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• 2003

An easily available, simultaneous identification/determination procedure for sildenafil, homosildenafil, tadalafil, vardenafil in adulterated health related foods was established by using a combination of three different analytical methods; thin layer chromatography(TLC), liquied chromatography-mass spectrometry (LC/MS) and high-performance liquied chromatography (HPLC)/photo-diode-array detector. The sample solution for TLC was applied to silica gel 60 $F_{254}$ plates with ethylacetate/acetonitrile/25%ammonia (90:10:5) as a developing solvent. Spots were located under UV radiation at 254 nm and dragendolfs reagent. Mass spectra of the compounds by LC/MS were investigated with electrospray ionization (ESI) interface, under positive ion mode. The HPLC analysis was performed on a column of capcell pack $C_{18}$ (UG120, 4.6${\times}$250mm I.D. 5 ${\mu}$m)with 0.1% sodium 1-hexansulfonate (in 0.1% phosphoric acid)/acetnitrile (73:27) as a mobile phase, and effluent was minitored with a photo-diode-applied to commercial foods, Sildenafil content was inthe range of 0.4mg/g~360.9 mg/g from 7 out of 35 samples. Homosildenafil content was in the range of 2.2 mg/g~336.0 mg/g from 7 out of 35 samples. Tadalafil content was 429.3 mg/g, 9.6 mg/500 mg from 2 out of 35 samples. The procedure described here is available for the screening of sildenafil, homosildenafil, tadalafil, vardenafil.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.264-270
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• 2013

Imidacloprid is a systemic insecticide which act as an insect neurotoxin. It used for control of pest such as aphids and other sucking insects in fruits and vegetables. Systemic pesticides move inside a crop following absorption by the plant, and these were converted into a variety of metabolites. Sometimes these metabolites make a problem about safety of agricultural products. So a simultaneous determination method of pesticide and its metabolites is needed, to monitor their presence in agricultural product and study on the fate of pesticide in a plant. This study's aim is to investigate simultaneous analysis method of imidacloprid and its metabolites, imidacloprid guanidine, imidacloprid olefin, imidacloprid urea, and 6-chloronicotinic acid in red pepper using QuEChERS method and LC-MS/MS systems. QuEChERS method was modifed beacuase $MgSO_4$ salts decreased the recoveries of 6-chloronicotinic acid in extraction procedure. Imidacloprid and its metabolites were extracted by acetonitrile with 1% glacial acetic acid and the extracts were purified through QuEChERS with primary secondary amine (PSA) and $C_{18}$ and analyzed with LC-MS/MS in ESI positive mode. Standard calibration curves were made by matrix matched standards and their correlation coefficients were higher than 0.999. Recovery studies were carried out on spiked pepper blank sample at four concentration levels (0.01, 0.04 and 0.1, 0.4 mg/kg). The average recoveries of imidacloprid and its metabolites were in the range of 70~120% with < 20% RSD. This result indicated that the method using QuEChERS and LC-MS/MS was suitable for the simultaneous determination of imidacloprid and its metabolites in red pepper.