• Analytical Science and Technology
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• v.11 no.3
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• pp.161-166
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• 1998

Analytical method of haloperidol (HAL) in serum which has been widely used in therapy of schizophrenic disorders is developed. Gas chromatography/nitrogen-phosphorus detection (GC/NPD) was used for this study. Bromoperidol was used as an internal standard and diethylether as a solvent of three-step extraction. The extraction yield in this procedure was $67.5{\pm}1.9%$ at 15 ng/mL. A good linear response in the range of 1~40 ng/mL was obtained with correlation coefficient of $r^2=0.999$. Detection limit was 0.5 ng/mL when 2 mL of serum was used. This method was applied for the analysis of HAL in serum of schizophrenic patients. After HAL decanoate (HD) was intaken as intramuscular route, HAL levels were determined at second week and forth week. From the result, the concentration of HAL at forth week appeared to 29.6% lower than those at second week. The present method showed low detection limit and high selectivity. Therefore it can be applied for the trace analysis of HAL in serum and the monitoring.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.517-524
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• 2004

The objective of this study was to investigate the environmental effects on duration time of milk flow, peak milk flow, and average milk flow in teats, and to estimate their relationships with milk yields in morning and evening milking, and to provide fimdamental information for the further study on their relationships with clinical mastitis and somatic cell in milk. A total of 6,768 milking records were studied in 72 Holstein cows. The influences of season, parity, lactation month, and milking interval on characteristics of milk flow considering in linear model were significant(p<.05). Duration of milk flow was longest at milking in fall, past first parity and second month of lactation, and with milking interval over than 13.5hrs. Average milk flow rate and peak milk flow rate were highest at milking in summer, past first parity and 8${\sim}$10 months of lactation, and with milking interval over than 13.5hrs. Milk flow rate was positively correlated to milk yield, and negatively correlated to the duration of milk flow. However duration milk flow was positively correlated to the milk yield with high level of correlation coefficient(+.60). For the establishment of optimum selection criteria on these traits, other aspects such as the udder health, disease and respective economic weights of milk flow characteristics in this study must be considered to develop the indices.

• Ecology and Resilient Infrastructure
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• v.7 no.2
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• pp.114-125
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• 2020

Despite the various artificial neural networks that have been developed, most of the discharge models in previous studies have been developed using deep neural networks. This study aimed to develop a discharge model using a convolution neural network (CNN), which was used to solve classification problems. Furthermore, the applicability of CNN was evaluated. The photographs (pictures or images) for input data to CNN could not clearly show the characteristics of the study area as well as precipitation. Hence, the model employed in this study had to use numerical images. To solve the problem, the CN of NRCS was used to generate images as input data for the model. The generated images showed a good possibility of applicability as input data. Moreover, a new application of CN, which had been used only for discharge prediction, was proposed in this study. As a result of CNN training, the model was trained and generalized stably. Comparison between the actual and predicted values had an R² of 0.79, which was relatively high. The model showed good performance in terms of the Pearson correlation coefficient (0.84), the Nash-Sutcliffe efficiency (NSE) (0.63), and the root mean square error (24.54 ㎥/s).

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.354-360
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• 2018

This study presents a method validation for extraction and quantitative analysis of trichothecene mycotoxins in nuts based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for extraction and enhanced matrix removal (EMR)-lipid-disperive-SPE (d-SPE) cleanup method, with detection and quantification by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in positive- and negative-ion modes. Linearity, precision, and accuracy were validated for LC-MS/MS methods. Results obtained with LC-MS/MS were linear, with correlation coefficient ($R^2$) of 0.998. Limits of detection and quantification for mycotoxins were $0.41-3.57{\mu}g/kg$ and $1.23-10.82{\mu}g/kg$, respectively. Intra- and inter-day precisions (RSD, %) were 0.40-8.44% and 1.93-12.46%, respectively. Results indicated to be rapidly and accurately identifying trichothecene mycotoxins and may be used as a suitable safety management method for nuts and nuts related commodities.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.1-8
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• 2007

Tortillas were prepared using rice and wheat flour. The experimental design incorporated thee independent variables(rice, wheat flour and moisture content) producing 14 samples of different proportions of each variable for each tortilla. The following were analysed using Design Expert 6 to unveil the influences of these variables on tensile strength and color(L, a, b). Results indicated that tensile strength increased with increasing rice and wheat flour content, however, decreased with increasing moisture content. Lighteness(L), of the tortilla increased with increased rice content whereas yellowness(b) increased with increased wheat flour content. The model suggests that tensile strength and color(L, a, b) in tortillas are highly correlated(SD Comment - give correlation coefficient and p-value). As well, the numerical optimization method suggests that the ratio of wheat flour to rice flour to moisture content which maximizes the three responses(tensile strenth, L and b) is 18.26 : 33.92 : 39.24%, 28.15 : 25.77 : 37.50%.

• Atmosphere
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• v.27 no.2
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• pp.225-233
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• 2017

Korea has recently suffered from severe hazes, largely being long-range transported from China but frequently mixed with domestic pollution. It is important to identify the origin of the frequently-occurring hazes, which is however hard to clearly determine in a quantitative term. In this regard, we suggest a possible classification procedure of various hazes into long-range transported haze (LH), Yellow Sand (YS), and urban haze (UH), based on mass loading of fine particles, time lag of PM mass concentrations between two sites aligned with dominant wind direction, backward trajectory of air mass, and the mass ratio of PM2.5 to PM10. The analysis sites are Seoul (SL) and Baengnyeongdo (BN), which are distant about 200 km from each other in the west to east direction. Aerosol concentrations at BN are overall lower than those of SL, indicative of BN being a background site for SL. We found distinct time lag of PM2.5 and PM10 concentrations between BN and SL in case of both LH and YS, but the intensity of YS being stronger than LH. Time scale (e-folding time scale) of LH appears to be longer and more variable than YS, which implies that LH covers much larger spatial scale. In addition, we found linear and significant correlations between ${\tau}_a$ obtained from sunphotometer and ${\tau}_{cal}$ calculated from surface aerosol scattering coefficient for LH episodes, relative to few correlation between those for YS, which might be associated with transported height of YS being much higher than LH. Therefore surface PM concentrations for the YS period are thought to be not representative for vertical integrated amount of aerosol loadings, probably by virtue of decoupled structure of aerosol vertical distribution. Improvement of various hazes classification based on the current result would provide the public as well as researchers with more accurate information of LH, UH, and YS, in terms of temporal scale, size, vertical distribution of aerosols, etc.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.23-31
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• 2006

carbon modified methods were used for the preconcentration and determination of copper in some real samples using the flame atomic absorption spectrometry. The copper ions was adsorbed quantitatively on the activated carbon due to their complexation with 4- amino-2, 3-dimethyl-1-phenyl-3-pyrazoline (ADMPP) or 4-(4- methoxybenzylidenimin) thiophenole (MBITP). The adsorbed copper on solid phase was eluted quantitatively using small amount of nitric acid. The influence of important parameters including pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were investigated. The methods based on ADMPP and MBITP at optimum conditions is linear over concentration range of 0.05-1.5 g mL-1 and 0.05-1.2 g mL-1 of copper with correlation coefficient of 0.9997 and 0.9994 and both detection limit of 1.4 ng mL-1, respectively. The preconcentration leads to enrichment factor of 310 and break through volume of 1550 mL for both ligands. The method has a good tolerance limit of interfering ion and a selectivity that has been successfully applied for the determination of copper content in real sample such as tap, spring, river and waste water.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.523-532
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• 2010

The proposed method is simple, sensitive and specific Liquid chromatography-tandem mass spectrometry (LCESI-MS/MS) method for the quantification of Entacapone (EA) in human plasma using Entacapone-d10 (EAD10) as an internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, $2.1{\times}50\;mm$, $5\;{\mu}m$ column, mobile phase composed of 10 mM Ammonium formate (pH 3.0): Acetonitrile (60:40 v/v), with a flow-rate of 0.7 mL/min, followed by Liquid-liquid extraction. EA and EAD10 were detected with proton adducts at m/z $306.1{\rightarrow}233.1$ and $316.3{\rightarrow}233.0$ in multiple reaction monitoring (MRM) positive mode respectively. The method was validated over a linear concentration range of 1.00 - 2000.00 ng/mL with correlation coefficient ($r^2$) $\geq$ 0.9993. Intra and inter-day Precision within 3.60 to 7.30 and 4.20 to 5.50% and Accuracy within 97.30 to 104.20 and 98.30 to 105.80% proved for EA. This method is successfully applied in the bioequivalence study of healthy Indian human volunteers.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.419-425
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• 2008

A qualitative and quantitative analytical method was developed for detection of methamphetamine (MA) and its main metabolite amphetamine (AM) in oral fluid. Oral fluids of eleven drug abusers were provided by Police, specimens were collected by stimulation with a cotton swab treated with 20 mg of citric acid ($Salivette^{(R)}$; Sarstedt, USA). As the preliminary test, oral fluid samples were screened for amphetamines by Fluorescence Polarization Immunoassay (TDxFLx, Abbott Co.). Extraction for MA was performed using solid-phase extraction (SPE) by $RapidTrace^{TM}$ (Zymark, USA) with mixed mode cation exchange cartridge, CLEAN $SCREEN^{(R)}$ (130 mg/3 ml, UCT) after dilution with phosphate buffer. Samples were evaporated and derivatized by pentafluoropropionic acid anhydride (PFPA). Quantitation of MA and AM was performed by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM), the quantitation ions were m/z 204 (MA), 208 (MA-$D_5$), 190 (AM) and 194 (AM-$D_5$). The selectivity, linearity of calibration, limit of detection (LOD) and quantification (LOQ) within- and between day precision, accuracy and recoveries were examined as parts of the method validation. All oral fluid samples gave positive results to immunoassay for MA (cut-off level, 50 ng/ml as d-amphetamine). Concentrations of MA and AM by GC-MS in eleven samples were ranged 104.2${\sim}$4603.3 ng/ml and 32.4${\sim}$268.6 ng/ml, respectively. Extracted calibration curves of MA and AM were linear over the two concentration range of 1${\sim}$100 and 50${\sim}$1000 ng/ml with correlation coefficient of above 0.999. LOQ of MA and AM was 1 and 3 ng/ml, respectively. The intraand inter-day run precisions (CV) for MA and AM were less than 10%, and the accuracies (bias) for MA and AM were also less than 10% at the two different concentrations 5 and 100 ng/ml at low calibration range, 50 and 1000 ng/ml at high calibration range. The absolute recoveries of MA and AM at low and high calibration ranges were more than 82% and 75%, respectively. In this study the qualitative and quantitative analytical method of MA in oral fluid was established. Oral fluid testing may detect drug use in past hours because of its shorter detection window than urine, and be useful in post-accident situations. So oral fluids will be most useful for testing drug abuse in the driving under the influence of drug (DUID) as the alternative specimens of urine.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.201-206
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• 2012

Benzo(a)pyrene is a polycyclic aromatic hydrocarbons (PAHs) whose metabolites are mutagenic and highly carcinogenic and is listed as a Group 1 carcinogen by the IARC. It has been found at variable concentrations in several foods and is associated with several factors during the process including contaminated raw materials, exposure of environment, and procedure of process or cooking. In this study, benzo(a)pyrene in 45 oriental medicines were determined by HPLC/FLD. The calibration curves of benzo(a)pyrene was linear over the concentration range of 0.5~40 ng/mL with correlation coefficient of above 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) of benzo(a)pyrene were 0.04 and 0.10 ${\mu}g/kg$. Benzo(a)pyrene in 3 samples out of 45 samples was not detected. The level of benzo(a)pyrene in 26 (57.7%), 8 (17.8%) and 7 (15.6%) samples was 0.1~0.5, 0.5~1.0 and 1.0~5.0 ${\mu}g/kg$, respectively. Especially, content of benzo(a)pyrene in Coptis Rhizome is the highest (5.97 ${\mu}g/kg$). In conclusion, these results suggest that could be applied to fundamental study and guideline on drying condition to decrease content of benzo(a)pyrene in oriental medicine.