• Title/Summary/Keyword: Liquid chromatography-mass

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Multi-residue Pesticide Analysis in Cereal using Modified QuEChERS Samloe Preparation Method (곡물류 중 잔류농약 다성분 분석을 위한 개선된 QuEChERS 시료 정제법의 개발)

  • Yang, In-Cheol;Hong, Su-Myeong;Kwon, Hye-Young;Kim, Taek-Kyum;Kim, Doo-Ho
    • The Korean Journal of Pesticide Science
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    • v.17 no.4
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    • pp.314-334
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    • 2013
  • This study explored an efficient modified Quick, Easy, Cheap, Effective, Rugged and safe (QuEChERS) method combined with liquid chromatography-electrospray ionization with tandem mass spectrometric detection for the analysis of residues of 76 pesticides in brown rice, barley and corn including acidic sulfonylurea herbicides. Formic acid (1%) acid in acetonitrile and dispersive solid phase extractions used for extraction of pesticides and clean-up of the extract respectively. Two fortified spikes at 50 and 200 ng $g^{-1}$ levels were performed for recovery test. Mean recoveries of majority of pesticides at two spike levels ranged from 73.2 to 132.2, 80.9 to 136.8, 66.6 to 143.5 for brown rice, barley and corn respectively with standard error (CV) less than 10%. Good linearity of calibration curves were achieved with $R^2$ > 0.9907 within the observed concentration ranged. The modified method also provided satisfactory results for sulfonylurea herbicides. The method was applied to the determination of residues of target pesticides in real samples. A total of 26 pesticides in 36 out of 98 tasted samples were observed. The highest concentration was observed for tricyclazole at 1.17 mg $kg^{-1}$ in brown rice. This pesticide in two brown rice samples exceeded their MRLs regulated for rice in republic of Korea. Except tricyclazole none of the observed pesticides' concentration was higher than their MRLs. The results reveal that the method is effectively applicable to routine analysis of residues of target pesticides in brown rice, barley and corn.

Analysis of ethyl glucuronide (EtG) in Hair for the diagnosis of chronic alcohol abuse of Korean (한국인의 만성 알코올 중독 진단을 위한 모발에서 Ethyl Glucuronide (EtG) 분석법 연구)

  • Gong, Bokyoung;Jo, Young-Hoon;Ju, Soyeong;Min, Ji-Sook;Kwon, Mia
    • Analytical Science and Technology
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    • v.33 no.3
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    • pp.151-158
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    • 2020
  • Alcohol, which can easily be obtained in the same way as ordinary beverages, is harmful enough to cause death due to excessive drinking and chronic alcohol intake, so it is important to maintain a proper amount of drinking and healthy drinking habits. In addition, the incidence of behavioral disturbances and impaired judgments that can be caused by chronic alcohol drinking of more than adequate amounts of alcohol is also significant. Accordingly it is very useful for forensic science to check whether the person involved is drunken or is alcoholism state in various accidents. Currently, in Korea, alcohol consumption is determined by detecting the level of alcohol or alcohol metabolism 'ethyl glucuronide (EtG)' in blood or urine samples. However, analysis of alcohol or EtG in blood or urine can only provide information about the current state of alcohol consumption because of a narrow window of detection time. Therefore, it is important to analyze the EtG as a long-term direct alcohol metabolite bio-marker in human hair and to investigate relationship between alcohol consumption and EtG concentration for the evaluation of chronic ethanol consumption. In this study, we established an analytical method for the detection of EtG in Korean hair efficiently and validated selectivity, linearity, limits of detection (LOD), limits of quantification (LOQ), matrix effect, recovery, process efficiency, accuracy and precision using liquid chromatography tandem mass spectrometry (LC-MS/MS). In addition, the assay performance was evaluated in Korean social drinker's hair and the postmortem hair of a chronic alcoholism. The results of this study can be useful in monitoring the alcohol abuse of Korean in clinical cases and legal procedures related to custody and provide a useful tool to evaluate postmortem diagnosis of alcoholic ketoacidosis in forensics.

Nitrate Concentration and ${\delta}^{15}N$ Value of the Groundwater in the Miyakojima Island, Okinawa Prefecture, Japan (일본(日本) 궁고도(宮古島)의 지하수중(地下水中)의 $NO_3-N$${\delta}^{15}N$치(値))

  • Park, Kwang-Lai;Kikuo, Kumazawa.
    • Korean Journal of Environmental Agriculture
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    • v.14 no.1
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    • pp.97-108
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    • 1995
  • Nitrate concentration and ${\delta}^{15}N$ value in the groundwater in Miyakojima Island, Okinawa, were measured during 1992-1993. Water from the shallow and the deep wells at the ten separate sites were sampled. Mineral contents and natural nitrogen isotope abundance(${\delta}^{15}N$) were analyzed using a liquid chromatography and a mass spectrometry (Finnigan MAT 252). Except for waters which were directly influenced by sea water invasion, most of the groundwater showed small variations among their mineral contents and ${\delta}^{15}N$ values. The average nitrate nitrogen concentrations were $1.4{\sim}11.5mgL^{-1}$ and average ${\delta}^{15}N$ values were +4.3${\sim}$+9.7$%_o$. From the nitrate concentration and ${\delta}^{15}N$ value observed, the types of the groundwater could be categorized into four groups, such as high ${\delta}^{15}N$ and high nitrate, high ${\delta}^{15}N$ and medium nitrate, low ${\delta}^{15}N$ and medium nitrate, and low ${\delta}^{15}N$ and low nitrate, reflecting the main source of nitrate contamination, such as animal and domestic waste, animal waste and soil organic matter, soil organic matter and chemical fertilizer, and chemical fertilizer, respectively. It was discussed that the lowest ${\delta}^{15}N$ value was higher than the ${\delta}^{15}N$ value of the chemical fertilizers used in this island(-3.9${\sim}$-1.4$%_o$), then considerable amounts of nitrogen must be lost by ammonium evaporation or denitrification after fertilization.

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Bioconcentration Factor(BCF) of Perchlorate from Agricultural Products and Soils (농산물과 토양에 대한 퍼클로레이트 함량 평가 및 생물농축계수 산출)

  • Kim, Ji-Young;Kim, Min-Ji;Lee, Jeong-Mi;Kim, Doo-Ho;Park, Ki-Moon;Kim, Won-Il
    • Korean Journal of Environmental Agriculture
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    • v.32 no.3
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    • pp.224-230
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    • 2013
  • BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

Isolation and Purification of Antimicrobial Peptide from Hard-shelled Mussel, Mytilus coruscus (참담치(Mytilus coruscus) 유래 항균 펩타이드 분리 및 정제)

  • Oh, Ryunkyoung;Lee, Min Jeong;Kim, Young-Ok;Nam, Bo-Hye;Kong, Hee Jeong;Kim, Joo-Won;An, Cheul Min;Kim, Dong-Gyun
    • Journal of Life Science
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    • v.26 no.11
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    • pp.1259-1268
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    • 2016
  • In this study, we investigated antimicrobial peptide from the acidified muscle extract of Mytilus coruscus, which mostly inhabits China, Japan, and Korea, to develop a natural product-derived antibiotics substitution in terms of its abuse and restriction. Antimicrobial peptide was purified by $C_{18}$ reversed-phase high-performance liquid chromatography and was detected as having a molecular mass of 6,701 Da by MALDI-TOF/MS. The N-terminal amino acid sequence of the purified peak was obtained from edman degradation, and 20 identified residues shown 100% identity with the N-terminus region of sperm-specific protein and protamine-like PL-II/PL-IV precursor of Mytilus californianus. We also identified 60 open-reading frame (ORF) encoding amino acids with 183 bp of purified peptide based on the obtained amino acid residues. The amino acid sequence of ORF showed 100% and the nucleotide sequence revealed 97.2% identity with the protamine-like PL-II/PL-IV precursor of Mytilus californianus. Synthesized antimicrobial peptide showed antimicrobial activity against gram-positive bacteria, including Bacillus cereus (minimal effective concentration [MEC], $20.8{\mu}g/ml$), Bacillus subtilis (MEC, $0.2{\mu}g/ml$), Streptococcus mutans (MEC, $0.2{\mu}g/ml$), gram-negative bacteria including Pseudomonas aeruginosa (MEC, $5.7{\mu}g/ml$), Escherichia coli (MEC, $2.6{\mu}g/ml$) and fungi, Candida albicans (MEC, $56.3{\mu}g/ml$). In addition, synthesized peptide showed stable activities under heat and salt conditions against gram-positive and gram-negative bacteria, but was inhibited by salt against only C. albicans. With these results, isolated peptide from M. coruscus could be an alternative agent to antibiotics for defending against pathogenic microorganisms, and helpful information to understand the innate immune system of marine invertebrates.

Characterization of Antibacterial Compounds from Bacillus polyfermenticus CJ6 and Its Growth Inhibition Effect on Food-Borne Pathogens (Bacillus polyfermenticus CJ6가 생산하는 항세균 물질의 특성 및 병원성 식중독 미생물의 성장 억제 효과)

  • Jung, Ji-Hye;Chang, Hae-Choon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.6
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    • pp.903-911
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    • 2011
  • In this study, Bacillus polyfermenticus CJ6 harboring antibacterial activity was isolated from meju. The antibacterial activity of Bacillus polyfermenticus CJ6 was stable in the pH range of 3.0~9.0, but it disappeared after culture at $70^{\circ}C$ for 24 hr. Antibacterial activity was inactivated by proteinase K, protease, and ${\alpha}$-chymotrypsin, indicating its proteinaceous nature. The growth inhibitory effects of B. polyfermenticus CJ6 culture on food-borne pathogens such as Staphylococcus aureus, Salmonella Typhi, Listeria monocytogenes, and Escherichia coli O157:H7 were examined in this study. Approximately 6~6.2 log CFU/mL of each pathogen was co-cultured with B. polyfermenticus CJ6 in a 50 mL culture volume for 24 hr. Growth of S. aureus and L. monocytogenes was completely inhibited after 3 hr of incubation. Growth of S. Typhi and E. coli O157:H7 was also completely inhibited after 6 hr of incubation. The antibacterial compounds from B. polyfermenticus CJ6 were purified by solid phase extraction (C18 Sep-pak cartridge), recycling preparative HPLC, and analytical HPLC. Ultra-high performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compounds, which were confirmed to be five peptides (757.4153 Da, 750.3444 Da, 1024.5282 Da, 1123.6083 Da, and 1617.8170 Da).

Simultaneous Analysis for Veterinary Drug Residues in Honey by HPLC/MS/MS (HPLC-MS/MS를 이용한 벌꿀 중 동물용의약품 동시분석방법 연구)

  • Kim, Jong-Hwa;Moon, Sun-Ea;Kim, Ki-Yu;Jung, You-Jung;Lee, Chang-Hee;Ku, Eun-Jung;Yoon, Mi-Hye;Lee, Jong-Bok
    • Journal of Food Hygiene and Safety
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    • v.31 no.2
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    • pp.94-98
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    • 2016
  • This study was conducted to establish the simultaneous analysis method for veterinary drug residues in honey by high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). The eleven targeting veterinary drugs with honey test method in Korean Food Standards Codex were divided into Group 1 (streptomycine dihydrostreptomycine, neomycine) and Group 2 (oxytetracycline, enrofloxacin, ciprofloxacin, cymiazole, chloramphenicol, amitraz, coumaphos, fluvalinate) to be analyzed simultaneously. From the results, the retention time (RT) of the targeting drugs was within 15 min, the range of detection limits was 0.0056 to $0.0643{\mu}g/g$ and the range of quantification limits was 0.0169 to $0.1948{\mu}g/g$. The coefficients of determination ($R^2$) for Group 1 ($0.05{\sim}1.0{\mu}g/mL$) and Group 2 ($0.01{\sim}1.0{\mu}g/mL$) were 0.9917~0.9987 and 0.9923~1.000 respectively, and showed the good linearity. The recovery rates for Group 1 (final conc. $0.25{\mu}g/g$) and Group 2 (final conc. $1.0{\mu}g/g$) were 65.1~80.6% and 64.2~90.3% respectively. Also, the analysis results of inter day (n = 3) and intra day (n = 6) RSD (%) for area and retention time showed that the RSD (%) for area and retention time was below 10.92% and 1.57%. Therefore, the simultaneous analysis method of this study is evaluated to be a good test method for veterinary drug residues in honey.

Ethyl acetate fraction from Pteridium aquilinum ameliorates cognitive impairment in high-fat diet-induced diabetic mice (고지방 식이로 유도된 실험동물의 당뇨성 인지기능 장애에 대한 고사리 아세트산에틸 분획물의 개선효과)

  • Kwon, Bong Seok;Guo, Tian Jiao;Park, Seon Kyeong;Kim, Jong Min;Kang, Jin Yong;Park, Sang Hyun;Kang, Jeong Eun;Lee, Chang Jun;Lee, Uk;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.49 no.6
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    • pp.649-658
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    • 2017
  • The potential of the ethyl acetate fraction from Pteridium aquilinum (EFPA) to improve the cognitive function in high-fat diet (HFD)-induced diabetic mice was investigated. EFPA-treatment resulted in a significant improvement in the spatial, learning, and memory abilities compared to the HFD group in behavioral tests, including the Y-maze, passive avoidance, and Morris water maze. The diabetic symptoms of the EFPA-treated groups, such as fasting glucose and glucose tolerance, were alleviated. The administration of EFPA reduced the acetylcholinesterase (AChE) activity and malondialdehyde (MDA) content in mice brains, but increased the acetylcholine (ACh) and superoxide dismutase (SOD) levels. Finally, kaempferol-3-o-glucoside, a major physiological component of EFPA, was identified by using high-performance liquid chromatography coupled with a hybrid triple quadrupole-linear ion trap mass spectrometer (QTRAP LC-MS/MS).

Development of analytical method for determination of spinetoram residues in livestock using LC-MS/MS (LC-MS/MS를 이용한 축산물 중 Spinetoram 공정시험법 개발 및 검증)

  • Ko, Ah-Young;Kim, Heejung;Do, Jung Ah;Jang, Jin;Lee, Eun Hyang;Ju, Yun Ji;Kim, Ji Young;Chang, Moon-Ik;Rhee, Gyu-Seek
    • Analytical Science and Technology
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    • v.29 no.2
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    • pp.94-103
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    • 2016
  • An analytical method was developed to determine the amount of spinetoram (spinetoram J and spinetoram L) in livestock samples. The spinetoram was extracted with acetonitrile and purified through a primary secondary amine (PSA) sorbent. The spinetoram residues were then quantified and confirmed using a liquid chromatography–tandem mass spectrometer (LC-MS/MS) in the positive ion mode using multiple reactions monitoring (MRM). Matrix-matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/kg) into a blank extract with r2 > 0.994. The limits of detection and quantification were 0.002 and 0.01 mg/kg, respectively. The recovery results of spinetram ranged between 81.9-106.4% at different concentration levels (LOQ, 10LOQ, 50LOQ, n=5) with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL40, 2003). An interlaboratory study was conducted to validate the method. The proposed analytical method proved to be accurate, effective, and sensitive for spinetoram determination. The method will be used as an official analytical method in Korea.

New Analytical Method to Identify Chromium Species, Cr(III) and Cr(VI), and Characteristic Distribution of Chromium Species in the Han River (한강수계해서의 크롬(III,VI) 종(species) 분포 및 분석방법 정립)

  • Jeong, Gwan-Jo;Kim, Dok-Chan;Park, Hyeon
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.6
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    • pp.590-598
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    • 2005
  • An adequate method to identify chromium separation, Cr(III) and Cr(VI), in water samples were studied by using High Performance Liquid Chromatography(HPLC) coupled with Inductively Coupled Plasma Mass Spectometer(ICP-MS) equipped with Dynamic Reaction Cell(DRC). The characteristic distribution of Cr(III) and Cr(VI) in the raw water taken at the six water intake stations in Seoul, was analyzed by the method developed by the authors. The chromium species separated by HPLC was isocratically conducted by using tetrabutylammonium phosphate monobasic(1.0 mM TBAP), ethylenediaminetetraacetic acid(0.6 mM EDTA) and 2% v/v methanol as the mobile phase. 5% v/v methanol was used as flushing solvent. A reactive ammonia($NH_3$) gas was used to eliminate the potential interference of $ArC^+$. Several Parameters such as solvent ratio, pH, flow rate and sample injection volume were optimized for the successful separation and reproducibility. Although it has been reported thai the separation sensitivity of Cr(III) is superior to that of Cr(VI), the authors observed Cr(VI) was more sensitive than Cr(III) when ammonia($NH_3$) gas was used as the reaction gas. It took less than 3 minutes to analyze chromium species with this method and the estimated detection limits were $0.061\;{\mu}g/L$ for Cr(III) and $0.052\;{\mu}g/L$, for Cr(VI). According to the results from the analysis on chromium species in the raw water of the six intake stations, the concentrations of Cr(III) ranged from 0.048 to $0.064\;{\mu}g/L$(ave. $0.054\;{\mu}g/L$) while that of Cr(VI) ranged from 0.014 to $0.023\;{\mu}g/L$(ave. $0.019\;{\mu}g/L$). Recovery ratio was very high($90.1{\sim}94.1%$). There were two or three times more Cr(III) than Cr(VI) in the raw water.