• Journal of Sensor Science and Technology
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• v.29 no.2
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• pp.128-132
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• 2020

Total organic carbon (TOC) analysis equipment, which was previously used to prevent eutrophication in advance, is heavy, bulky, and expensive; therefore, so it is difficult to be carried and has been used as an experimental unit. In this study, a through-carbon analysis chip that integrates pretreatment through photocatalytic oxidation and carbon dioxide measurement using a pH indicator was investigated. Both the total carbon - inorganic carbon method and the nonpurgeable organic carbon (NPOC) measurement method require an acidification part for injecting an acid solution for inorganic carbon measurement and removal, an oxidation part for total carbon or NPOC oxidation and a measurement part for Carbon dioxide (CO₂) measurement. Among them, the measurement of oxidation and CO₂ requires physical technology. The proposed TOC analysis chip decomposed into CO₂ as a result of the oxidizing of organic carbon using a photocatalyst, and the pH indicator that was changed by the generated CO₂ was optically measured. Although the area of the sample of the oxidation part and the pH indicator of the measurement part were distinguished in an enclosed space, CO₂ was quantified by producing an oxidation part and a measurement part that shared the same air in one chip. The proposed TOC analysis chip is less expensive and smaller, cost and size are disadvantages of existing organic carbon analysis equipment, because it does not require a separate carrier gas to transport the CO₂ gas in the oxidation part to the measurement part.

• Textile Coloration and Finishing
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• v.29 no.1
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• pp.11-17
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• 2017

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that can not be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor(MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbenedisulfonic acid derivative by ozone oxidation were evaluated by $UV_{254}$ Scan, $COD_{Mn}$, T-N and color using a synthetic wastewater sample ($COD_{Mn}=433.0mg/{\ell}$) and paper and paper mill wastewater ($COD_{Mn}=157.2mg/{\ell}$).

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1248-1248
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• 2001

Mastitis is a major problem for the global dairy industry and causes substantial economic losses from decreasing milk production and considerable compositional changes in milk, reducing milk quality. The potential of near infrared (NIR) spectroscopy in the region from 1100 to 2500nm and chemometric method for classification to detect milk from mastitic cows was investigated. A total of 189 milk samples from 7 Holstein cows were collected for 27 days, consecutively, and analyzed for somatic cells (SCC). Three of the cows were healthy, and the rest had mastitis periods during the experiment. NIR transflectance milk spectra were obtained by the InfraAlyzer 500 spectrophotometer in the spectral range from 1100 to 2500nm. All samples were divided into calibration set and test set. Class variable was assigned for each sample as follow: healthy (class 1) and mastitic (class 2), based on milk SCC content. The classification of the samples was performed using soft independent modeling of class analogy (SIMCA) and different spectral data pretreatment. Two concentration of SCC - 200 000 cells/ml and 300 000 cells/ml, respectively, were used as thresholds fer separation of healthy and mastitis cows. The best detection accuracy was found for models, obtained using 200 000 cells/ml as threshold and smoothed absorbance data - 98.41% from samples in the calibration set and 87.30% from the samples in the independent test set were correctly classified. SIMCA results for classes, based on 300 000 cells/ml threshold, showed a little lower accuracy of classification. The analysis of changes in the loading of first PC factor for group of healthy milk and group of mastitic milk showed, that separation between classes was indirect and based on influence of mastitis on the milk components. The accuracy of mastitis detection by SIMCA method, based on NIR spectra of milk would allow health screening of cows and differentiation between healthy and mastitic milk samples. Having SIMCA models, mastitis detection would be possible by using only DIR spectra of milk, without any other analyses.

• Analytical Science and Technology
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• v.11 no.4
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• pp.281-291
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• 1998

An analytical method for the simultaneous measurement of trace Cu, Sn, and Bi in blood and urine has been investigated by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Microwave oven was used for the pretreatment of blood samples using nitric acid and hydrogen peroxide in a closedvessel digestion system with 1 mL whole blood for 8 minutes. Amberlite IRC-718 resin was used as a solid phase in solid-liquid extraction technique for the removal of matrix interferences such as Na, S, P, and other polyatomic ion species. Detection limits for Cu, Sn, and Bi by this method were 0.000375 ng/mL, 0.000297 ng/mL, and 0.000174 ng/mL, respectively. Recoveries of 99.1% for Cu, 102.5% for Sn, and 98.4% for Bi were obtained for the standard spiked NIST SRM 955a blood sample. The developed method was applied for whole real blood and urine samples.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1604-1608
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• 2000

Penicillin antibiotics such as penicillin G, ampicillin and amoxicillin have been widely used in the pig industry to control salmonellosis, bacterial pneumonia, and urinary tract infections. Extensive use of antibiotics in veterinary clinics has resulted in tissue residues and bacterial resistance. To prevent unwanted drug residues entering the human food chain, extensive control measures have been established by both government authorities and industries. The demands for reliable, simple, sensitive, rapid and low-cost methods for residue analysis of foods are increasing. In this study, we established a rapid prediction test for the detection of pigs with unacceptable tissue residues of penicillins. The recommended therapeutic doses of three penicillins, penillin G (withdrawal time, 7 days), ampicillin (withdrawal time, 7 days) and amoxicillin (withdrawal time, 14 days), were administered to three groups of 20 pigs each. Blood was sampled before drug administration and during the withdrawal period. The concentration of penicillins in plasma, determined by a semi-quantitative ELISA, were compared to that of internal standard, 4 ppb, which corresponded to the Maximum Residue Limit in milk. The absorbance ratio of internal standard to sample (B/Bs) was employed as an index to determine whether drug residues in pig tissues were negative or positive. That is, a B/Bs ratio less than 1 was considered residue positive, and larger than 1 negative. All 60 plasma samples from pigs were negative to three penicillins at pretreatment. Penicillin G could be detected in the plasma of the treated pigs until day 4 post-treatment and ampicillin until day 2, whereas amoxicillin could be detected until day 10 of its withdrawal period. The present study showed that the semi-quantitative ELISA could be easily adapted to detect residues of penicillin antibiotics (penicillin G, ampicillin and amoxicillin) in live pigs.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.408-415
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• 2020

In this study, the AE-SOM method, which combines auto-encoder and self-organizing map, is used to detect and diagnose faults in EVA production process. Then, the fault propagation pathways are identified using Granger causality test. One year and seven months of operation data were obtained to detect faults of the process, and the process variables of the autoclave reactor are mainly analyzed. In the data pretreatment process, the data are standardized and 200 samples of each grade are randomly chosen to obtain a fault detection model. After that, the best matching unit (BMU) of each grade is confirmed by applying AE-SOM. The faults are determined based on each BMU. When a fault is found, the most causative variable of the fault is identified by using a contribution plot, and the fault propagation pathway is identified by Granger causality test. The prognostic of the two shutdowns is detected, and the fault propagation pathway caused by the faulty variable was analyzed.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.258-261
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• 2009

In this work, we the ettect on extraction amounts and general composition content of phytoestrogen genistein and formononetin extracted from Sophoraflavescens Aiton by various ultrasonic waves(35, 72, and 170 KHz) and extraction time(30, and 60 min) were compared using extraction solvent water 100%. The pretreatment step was composed of ultrasonic waves extraction, filtration, concentration, and membrane filtration. The extracted sample was analyzed by reversed-phase high performance liquid chromatography(RP-HPLC). And the mobile phase applied was linearly changed with A/B of 80/20~65/35 vol% for 60 min(A water/acetic acid, 99.9/0.1 vol%, B acetonitrile/acetic acid, 99.9/0.1 vol%). The experimental results, general composition carbohydrate(0.255 to 0.413%) excepts, other ingredients was confirmed almost similarly. Also, The highest yield of extraction amount 3.17g was obtained by ultrasonic waves with a frequency of 170 KHz and an extraction time of 60 min. This work offers would be useful for chemical and biological studies of natural plants and its products.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.360-367
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• 2020

In this study, the accumulation and distribution routes of microplastics in soil environment were examined, and their analytical methodologies were summarized. Density separation and removal process of inhibition materials were introduced for the separation of microplastics in soil and the basic principles and limitations of quantitative and qualitative analyses including pyrolysis gas chromatography mass spectrometry, µ-Raman spectrometry, fourier transform infrared spectrometry, and microscopes were investigated. Chemical extraction methods for the analysis of mediated hazardous substance (additives and sorbed matters) in microplastics were also discussed with focusing on in vitro bioaccessibility assay for the human oral exposure route. Based on the described methodologies for the analysis of microplastics in soil, it is expected that these methods enable to select appropriate analysis techniques in consideration of medium state, contamination level and sample quantity.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.49-59
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• 1997

This study was performed to analyze the purity of technical grade ${\alpha}$-naphthylamine, to establish optimal analytical condition of ${\alpha}$-naphthylamine in urine and to determine the urine sample of workers exposed to ${\alpha}$-naphthylamine. The purity of technical grade ${\alpha}$-naphthylamine were $96.5{\pm}2.38%$, $94.1{\pm}0.97%$, $97.0{\pm}0.02%$ by gas chromatography-mass selective detector. To analyze ${\alpha}$-naphthylamine in urine, high performance liquid chromatography-electrochemical detector and gas chromatography-electron capture detector operating conditions have been optimized by preliminary expriment. In high performance liquid chromatography-electrochemical detector, the mobile phase was consisted of acetonitrile(35%) and water(65%), and the flow rate was maintained at 1.0ml per minute. Optimal detective condition was 9.0V(10nA/V) of electrochemical detector. The recovery of sep-pak treatment method was highly estimated as pretreatment of ${\alpha}$-naphthylamine in urine. The free amine was isolated by gas chromatography-electron capture detector after basic hydrosis, sep-pak treatment, toluene elution and HFBA(heptafluoro-butyric anhydride) derivatization of urine. The recovery of ${\alpha}$-naphthylamine in urine was $98.73{\pm}3.29%$ by gas chromatography-electron capture detector. The sensitivity was more higher than that of high performance liquid chromatography-electrochemical detector. Urinary ${\alpha}$-naphthylamine was detected in only one worker among nine workers. The level of ${\alpha}$-naphthylamine in urine was 6.42 ng/ml.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4679-4683
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• 2013

Background: ERCC1 is considered as a promising molecular marker that may predict platinum based chemotherapy response in non small cell lung cancer patients. We therefore investigated whether its expression is indeed associated with clinical outcomes in advanced stage NSCLC patients. Materials and Methods: Pretreatment tumor biopsy samples of 83 stage 3B and 4 non-small cell lung cancer patients treated with platinum based chemotherapy were retrospectively analyzed for immunohistochemical ERCC1 expression. None of the patients received curative surgery or radiotherapy. Results: By calculating H- scores regarding the extent and intensity of immunohistochemical staining of tumor biopsy samples, ERCC1 expression was found to be positive in 50 patients (60.2%). ERCC1 positive and negative groups had no statistically significant differences regarding treatment response, progression free survival and overall survival (respectively p=0.161; p=0.412; p=0.823). Conclusions: In our study we found no association between ERCC1 expression and survival or treatment response. The study has some limitations, such as small sample size and retrospective analysis method. There is need of more knowledge for use of ERCC1 guided chemotherapy regimens in advanced stage NSCLC.