• 분석과학
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• 제13권6호
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• pp.802-809
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• 2000

국내의 다양한 장소에서 채취된 수질 43종, 토양 35종 및 저질 11종 중에 포함 되어있는 polychlorinated biphenyls (PCBs)의 congeners 성분들을 GC/MS를 이용하여 분석하였다. 분석 결과 수질시료의 평균 회수율은 $83.8{\pm}10.4%$이며, 토양 및 저질시료의 평균 회수율은 $94.9{\pm}12.2%$였으며, $^{13}C{_{12}}$-PCBs(Surlegate)에 대한 회수율도 $80.2{\pm}8.7%$로 비교적 양호하였다. 검출 한계는 수질의 경우 0.01 ng/ml이며, 토양 및 저질의 경우 0.05 ng/g로 결정되었다. 수질시료는 정량한계 범위 내에서 검출되지 않았으나, 토양 및 저질시료에서는 대부분의 시료에서 한 개 이상의 PCBs congener가 검출되었다. 이번 국내의 PCBs 생태계 오염 실태조사 결과는 미국, 유럽 및 일본과 같은 선진국에 비해 PCBs의 오염도가 상당히 낮은 것으로 평가되었다.

• 한국환경농학회지
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• 제39권2호
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• pp.122-129
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• 2020

BACKGROUND: Dissipation patterns of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry grown in plastic-covered greenhouse were evaluated at 7 intervals including the preharvest interval after application. This study was performed to determine the residue concentrations, half-lives and dissipation rates in strawberry for the harvest periods. METHODS AND RESULTS: Acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam were applied in accordance with critical good agricultural practices for strawberry. Strawberry samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after application. Quantitaion was performed by HPLC/DAD and HPLC-MSMS system with C₁₈ column. The limit of quantitation (LOQ) values varied between were 0.00025~0.05 mg/kg on strawberry. The recoveries of acequinocyl, clothianidin, diflubenzuron, thiacloprid and thiamethoxam at two concentrations ranged from 70.9~104.9% on strawberry. The half-lives of pesticide dissipation on strawberry for two fields ranged from 1.3~8.2 days. The dissipation rates were evaluated according to the statistics method with a 95% confidence. CONCLUSION: The residue levels of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry at 0-day after application were below the specified values by Korean MRL. To estimate dissipation rate constant of pesticides on crop for harvest periods, it is important to set the pre-harvest residue limit for human health and consumer protection in Korea.

• Food Science and Biotechnology
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• 제18권1호
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• pp.113-117
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• 2009

A method was developed using enhanced liquid chromatography coupled with electrospray ionization mass spectrometry for the analysis and quantitation of 2 main potato glycoalkaloids, $\alpha$-chaconine, and $\alpha$-solanine, without any pre-concentration or derivatisation steps. Calibration curves generated by this technique exhibited a linear dynamic range from 0.025 to $50{\mu}g/mL$ and from 0.05 to $50{\mu}g/mL$ for $\alpha$-chaconine and $\alpha$-solanine, respectively. Matrix effects were evaluated by comparing calibration curves measured in matrix-matched and solvent-based systems. Ion suppression due to matrix effects was weak and extraction recoveries of 88 to 114% were obtained in different sample matrices spiked with analyte concentrations ranging from 15 to $35{\mu}g/mL$. Potatoes that had been genetically modified to tolerate glufosinate contained the same glycoalkaloid levels as their non-transgenic counterpart. We suggest complementing compositional comparison assessment strategy by validating quantitative analytical methods for the toxic glycoalkaloids in potato plants.

• 한국축산식품학회지
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• 제31권2호
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• pp.191-199
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• 2011

The objective of this study was to develop a method to simultaneously quantify vitamins A and E in infant formula. To determine the vitamin A and E content, vitamin A and four different vitamin E isomers (${\alpha}$-, ${\beta}$-, ${\gamma}$-, and ${\delta}$-tocopherol) were separated by high performance liquid chromatography with a photodiode array detector using a Develosil RPAQUEOUS RP-$C_{30}$ column ($4.6{\times}250$ mm, 5 ${\mu}M$). The vitamin A and E contents in the certified reference material determined using this method were within the certified range of standard values. The limits of detection (LODs) and limits of quantitation (LOQs) for vitamin A were 0.02 and 0.06 ${\mu}g/L$, respectively. LODs and LOQs for the vitamin E isomers ranged from 0.20 to 0.55 and from 0.67 to 1.81 ${\mu}g/L$, respectively. Linear analyses indicated that the square of the correlation coefficient for the vitamin A and E isomers was 0.9997-0.9999. The recovery of vitamins ranged from 96.69 to 97.79%. The results demonstrate that this novel method could be used to reliably analyze vitamin A and E content in infant formula.

• 한국식품과학회지
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• 제4권4호
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• pp.309-316
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• 1972

고구마의 지질(脂質)을 유리지질(遊離脂質)과 결합지질(結合脂質)로 분리하고, thin layer chromatography에 의하여 각종 성분으로 분별(分別), 동정(同定), 정량(定量) 하였으며 그들의 flavor를 검사하여 다음의 결과를 얻었다. 1) 고구마의 총지질(脂質)은 1.75%로서 (고형물(固形物)당), 유리지질(遊離脂質)은 0.95%, 결합지질(結合脂質)은 0.80% 이었다. 2) TLC에 의하여 유리지질(遊離脂質)에서 13개, 결합지질(結合脂質)에서 9개의 성분(成分)을 분리(分離), 정량(定量)하였으며 phospholipid가 34.5%, 유리지방산이 17.2%로서 가장 많았다. 3) Reversed TLC 에 의하여 지방산을 분리(分離), 정량(定量)한 결과 palmitic acid 30.1%, linoleic acid 16.7%, oleic acid 15.8% linolenic acid 9.8%로서 가장 많은 양을 보였다. 여러 가지 지질획분(脂質劃分)의 flavor 관찰한 결과 고구마가 갖고 있는 나쁜 맛과 냄새는 주로 결합지질(結合脂質)에 존재하였다.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.106-112
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• 2020

Analyzing vitamin D levels is important for monitoring health conditions because vitamin D deficiency is associated with various diseases such as rickets, osteomalacia, cardiovascular disorders and some cancers. However, vitamin D concentration in the blood is very low with optimal level of 75 nmol/L, making quantitative analysis difficult. The objective of this study was to develop a highly sensitive analysis method for vitamin D using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS). 25-hydroxyvitamin D (25(OH)D), which has been used as an indicator of vitamin D metabolites in human biofluids was chemically derivatized using a secosteroid signal enhancing tag (SecoSET) with powerful dienophile and permanent positive charge. The SecoSET-derivatized 25(OH)D provided good linearity (R² > 0.99) and sensitivity (limit of quantitation: 11.3 fmol). Chemical derivatization of deuterated 25-hydroxyvitamin D₃ (d₆-25(OH)D3) with SecoSET enabled absolute quantitative analysis using MALDI-MS. The highly sensitive method could be successfully applied into monitoring of quantitative changes of bioactive vitamin D metabolites after treatment with ketoconazole to inhibit 1α-hydroxylase reaction related to vitamin D metabolism in human breast cancer cells. Taken together, we developed a MALDI-MS-based platform that could quantitatively analyze vitamin D metabolites from cell products, blood and other biofluids. This platform may be applied to monitor various diseases associated with vitamin D deficiency such as rickets, osteomalacia and breast cancer.

• Safety and Health at Work
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• 제11권2호
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• pp.143-151
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• 2020

Objective: Bidi is an inexpensive, low-processed, hand-rolled tobacco product. In Bangladesh, especially in Rangpur, tobacco farming and bidi processing are common. In this study, we aimed to evaluate the impact of bidi making on children working in bidi factories. Methods: This qualitative(walk-through survey) and quantitative(questionnaire-based survey and a urine cotinine level quantitation) study was conducted in Rangpur, Bangladesh in 2017. Study population included child-workers aged ≤14 years who were regularly employed as bidi makers. Findings: The results of the walk-through survey revealed hazardous working environments at bidi factories. For the quantitative survey, 171 child-workers were categorized into "less-working"(<5 hours/day) and "more-working"(≥5 hours/day) groups; additionally, "forced-working"(forced into work by parents) and "voluntary-working"(working voluntarily) groups were delineated within the same population. In the logistic regression analysis, odds ratios(ORs) of respiratory symptoms and unusual absence(absent ≥5 days/month) were higher in the "more-working" group than in the "less-working" group(unusual absence: OR, 2.91; 95% confidence interval[CI], 1.43-5.94), and this association became higher in the "forced-working" group with longer working hours(OR, 5.68, 95%CI 2.30-14.00). Conclusions: Cheap, hand-rolled tobacco(bidi) is harmful to the health of bidi-making child-workers. Children in poverty bow to the demands of cheap labor and poverty and jeopardize their health and future prospects by working in bidi factories. Tobacco control policies should consider the social effects of tobacco beyond its biological effects.

• 약학회지
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• 제49권3호
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• pp.212-216
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• 2005

A rapid, sensitive and selective electrospray tandem mass spectrometric (ESI-LC/MS/MS) method for the quantitation of gliquidone in human plasma was developed. A bioavailability study of gliquidone tablet (30 mg gliquidone, Boehringer Ingelheim Korea Co.) was performed using the validated ESI-LC/MS/MS method. The dose of 30 mg of gliquidone (1 tablet) was orally administered to 9 healthy Korean subjects. After administration, blood was taken at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 7, 9, 12, 24, and 33 hour. The validation data were as follows; the standard curve was linear ($r^2$=0.999) over the concentration range of $10\~1000 ng/ml$. The coefficient of variation for intra- and inter-day assay were $8.30\~18.86$, and $2.19\~12.92\%$, respectively. The lower limit of quantification for gliquidone was 10 ng/ml. The pharmacokinetic parameters obtained were as follows; $AUC_t$ was 3861.17$\pm$1328.61 ng-hr/ml, $C_{max}$ was 831.02$\pm$227.99 ng/ml, $T_{max}$ was $2.94{\pm}0.77 hr,\;K_e$, was 0.19$\pm$0.06 1/hr, and $t_{l/2}$ was 4.47$\pm$3.52 hr. Based on the validated analytical method and pharmacokinetic parameters, a standard guideline of the bioavailability test of gliquidone dosage forms was prepared successfully and could be used for the bioequivalence test of gliquidone preparation.

• 약학회지
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• 제49권3호
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• pp.225-229
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• 2005

A rapid, sensitive and selective tandem mass spectrometric method (LC-MS/MS) for the quantitation of nicorandil in human plasma was developed. A bioavailability study of Sigmat tablet (5 mg nicorandil, Choongwae Co.) was per-formed using the validated LC-MS/MS method. The dose of 5 fig of nicorandil (1 tablet) was orally administered to 9 healthy Korean subjects. After administration, blood was taken at 0.25, 0.5, 1, 2, 3, 4, 5, 6, 9, 12, and 24 hour. The validation data were as follows; the standard curve was linear ($r^2$=0.999) over the concentration range of $0.5\~200.0 ng/ml$. The coefficient of variation for intra- and inter-day assay were $3.55\~7.44$, and $2.17\~9.102\%$, respectively. The lower limit of quantification for nicorandil was 0.5 ng/ml. The pharmacokinetic parameters obtained were as follows; $AUC_t$ was 145.9$\pm$83.0 ng-hr/ml, Cmax was 83.8$\pm$32.2 ng/ml, $C_{max}$ was 0.42$\pm$0.13 hr, $K_e$ was 0.56$\pm$0.23 l/hr, and $t_{l/2}$ was 1.42$\pm$0.52 hr. Based on the validated analytical method and pharmacokinetic parameters, a standard guideline of the bioavailability test of nicorandil dos-age forms was prepared successfully and could be used for the bioequivalence test of nicorandil preparation.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3444-3450
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• 2013

Three phase hollow fiber-liquid phase microextraction (HF-LPME), which is faster, simpler and uses a more environmentally friendly sample-preparation technique, was developed for the analysis of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in human urine. For the effective simultaneous extraction/concentration of NSAIDs by three phase HF-LPME, parameters (such as extraction organic solvent, pH of donor/acceptor phase, stirring speed, salting-out effect, sample temperature, and extraction time) which influence the extraction efficiency were optimized. NSAIDs were extracted and concentrated from 4 mL of aqueous solution at pH 3 (donor phase) into dihexyl ether immobilized in the wall pores of a porous hollow fiber, and then extracted into the acceptor phase at pH 13 located in the lumen of the hollow fiber. After the extraction, 5 ${\mu}L$ of the acceptor phase was directly injected into the HPLC/UV system. Simultaneous chromatographic separation of seven NSAIDs was achieved on an Eclipse XDB-C18 (4.6 mm i.d. ${\times}$ 150 mm length, 5 ${\mu}m$ particle size) column using isocratic elution with 0.1% formic acid and methanol (30:70) at a HPLC-UV/Vis system. Under optimized conditions (extraction solvent, dihexyl ether; $pH_{donor}$, 3; $pH_{acceptor}$, 13; stirring speed, 1500 rpm; NaCl salt, 10%; sample temperature, $60^{\circ}C$; and extraction time, 45 min), enrichment factors (EF) were between 59 and 260. The limit of detection (LOD) and limit of quantitation (LOQ) in the spiked urine matrix were in the concentration range of 5-15 ng/mL and 15-45 ng/mL, respectively. The relative recovery and precision obtained were between 58 and 136% and below 15.7% RSD, respectively. The calibration curve was linear within the range of 0.015-0.96 ng/mL with the square of the correlation coefficient being more than 0.997. The established method can be used to analyse of NSAIDs of low concentration (ng/mL) in urine.