• Korean Journal of Medicinal Crop Science
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• v.21 no.3
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• pp.213-219
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• 2013

This study was carried out to find out the optimum method of preparation of indigo standard solution and its stability, and to investigate the indigo contents in Niram, blue dye extract, from a total of 7 indigo plants and 34 breeding lines of Persicaria tinctoria H. Gross. Proper solvent for indigo standard was dimethyl sulfoxide (DMSO), and appropriate concentration was 1 mg of indigo in 10 mL of DMSO. Absorbance value of UV/Vis Spectrophotometer at 620 nm of standard solution was changed decreasingly 12 hours after the preparation of standard solution irrespective of the storage conditions such as temperature and light. Average value of absorbance of 8-fold diluted standard solutions prepared daily during 16 days was $0.210{\pm}0.005$, indicating the powder of indigo compound was stable chemically. Calibration curve was made for quantitative analysis of indigo of 7 Niram samples, and indigo contents ranged from 0.69% to 18.76% showing relatively larger variation. Across all 34 breeding lines, the range of indigo content was from 7.9 mg to 56.4 mg per 100 g of fresh leaves, averaging 25.2 mg of indigo content and showing a 47.7% coefficient of variation.

• Analytical Science and Technology
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• v.23 no.6
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• pp.572-578
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• 2010

The extraction/clean-up and concentrating of pharmaceuticals from surface water were performed by HLB (Hydrophilic-Lipophilic Balanced) cartridge. The method allows for the simultaneous determination of six pharmaceuticals by HPLC/ESI(+)-MS/MS. Recoveries of the pharmaceutical were between 71.1 to 92.6% (except fenbendazole) and the overall variability of the method was below 11.2% (RSD). The calibration curves for the pharmaceuticals from blank surface water showed good linearities (above $r^2$ = 0.99) in the concentration range of 0.007~1.2 ng/mL. The limit of detection (LOD) and the limit of quantification (LOQ) were 7.2~128.7 pg/mL and 23.8~429.1 pg/mL, respectively. The present analytical method can be useful for monitoring residual pharmaceuticals in surface water and other aquatic samples. High concentrations of iopromide and fenbendazole were detected in a few samples of surface water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.459-464
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• 2017

Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1530-1530
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• 2001

The objectives of this study were to develop models to predict quality parameters of Korean bee-honeys by visible and NIR spectroscopic technique. Two kinds of bee-honey fronl acacia and polyflower sources were tested in this study. The honeys were harvested in the spring of 2000 and stored in the storage facility at 20$^{\circ}C$ during experiments. Total of 394 samples of honey were analyzed. Reflectance spectra, moisture contents, ash, invert sugar, sucrose, F/G (fructose/glucose) ratio, HMF (hydroxymethyl furfural), and C12/C13 ratio of honeys were measured. The average values for the tested honeys were 19.9% of moisture contents, 0.12% of ash, 68.4% of invert sugar, 5.7% of sucrose, 1.27 of F/G(fructose/glucose) ratio, 14.4 mg/kg of HMF, and -19.1 of C12/C13 ratio. A spectrophotometer, equipped with a single-beam scanning monochromator (NIR Systems, Model 6500, USA) and a horizontal setup module, was used to collect reflectance data from honey. The reflectance spectra were measured in wavelength ranges of 400∼2,498 nm. with 2 nm of interval. Thirty-two repetitive scans were averaged, transformed to log(1/Reflectance), and then were stored in a microcomputer file, forming one spectrum per measurement. A sample cell and reflectance plate were made to hold honey samples constantly. Spectra of honey samples were divided into a calibration set and a validation set. The calibration set was used during model development, and the validation set was used to predict quality parameters from unknown spectra. The PLS(Partial Least Square) models were developed to predict the quality parameters of honeys. The first and the second derivatives of raw spectra were also used to develop the models with proper smoothing gap. The MSC (multiplicative scatter correction) and the SNV & Dtr.(standard normal variate and detranding) preprocessing were applied to all spectra to minimize sample-to-sample light scatter differences. The PLS models showed good relationships between predicted and measured quality parameters of honeys in the wavelength range of 1100∼2200 nm. However, the PLS analysis was not good enough to predict HMF of honeys.

• Agricultural and Biosystems Engineering
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• v.7 no.1
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• pp.8-12
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• 2006

This study was conducted to develop a real-time internal quality evaluation technique for Korean red ginseng using NIR spectroscopy while they were moving to be graded. Internal qualities of Korean red ginseng were defined by color, amount of white core and cavity in the red ginseng. To evaluate the internal quality, PLS (Partial Least Square) model was developed. Spectrum saturation can be occurred when most red ginseng has a sound internal quality expressed by higher light transmittance ratio, but that could not found in the ginseng of internal white core under the same light situation. And, if spectrum saturation is obtained, it is hard to identify the exact information of internal quality. In order to evaluate of the internal quality regardless of having internal normal core or white core, an integral time controlled method was used to obtain traditional spectrum. This procedure was applied in real-time process when red ginseng was moving to be graded in the line. Among the 450 samples including 223 internal normal ginsengs and 227 internal white core ginsengs, 315 ginsengs (70%) were used to develop a calibration model and 135 ginsengs were spent to validate the model. The result of quality evaluation by the model was very good showing SEP and bias were 0.3573 and 0.0310, respectively, and the accuracy was 95.6%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.253-270
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• 2013

To achieve accurate localization information, complex algorithms that have high computational complexity are usually implemented. In addition, many of these algorithms have been developed to overcome several limitations, e.g., obstruction interference in multi-path and non-line-of-sight (NLOS) environments. However, localization systems those have complex design experience latency when operating multiple mobile nodes occupying various channels and try to compensate for inaccurate distance values. To operate multiple mobile nodes concurrently, we propose a localization system with both low complexity and high accuracy and that is based on a chirp spread spectrum (CSS) radio. The proposed localization system is composed of accurate ranging values that are analyzed by simple linear regression that utilizes a Big-$O(n^2)$ of only a few data points and an algorithm with a self-calibration feature. The performance of the proposed localization system is verified by means of actual experiments. The results show a mean error of about 1 m and multiple mobile node operation in a $100{\times}35m^2$ environment under NLOS condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.353-364
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• 1998

This paper describes the design processes and evaluation results of a small-sized six-axis force/torque sensor. The new six-axis force/torque sensor including S-type structure has been developed using a parallel plate structure as a basic sensing element. In order tominimize coupling errors, the location of strain gages has been determined based on the finite element analysis and the connections of strain gages have been made such that the bridge circuit with 4 strain gages becomes balanced. Several design modifications result in a similar strain sensitivity for six-axis forces and moments, and the reduced coupling errors of 2.6% FS between each forces and moments. Calibration test results show that the six-axis load cell developed which has light weight of 135g and the maximum capacities of 196 N in forces and 19.6 N.m in moments is estimated to be within 7.1% FS in coupling error.

• The Journal of Korean Medicine
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• v.31 no.6
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• pp.8-15
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• 2010

Objectives: We investigated to develop and validate HPLC-PDA methods for simultaneous determination of eight constituents in Galgeun-tang (GGT). Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230 nm, 254 nm, and 280 nm, were used for quantification of the eight marker components of GGT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Results: Calibration curves were acquired with $r^2$ > 0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each component was in the range of 87.33-101.38%, with an RSD less than 7.0%. The contents of the eight components in GGT were 1.98-12.17 mg/g. Conclusions: The established method will be applied for the quantification of marker components in GGT.

• Korean Journal of Pharmacognosy
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• v.49 no.1
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• pp.70-75
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• 2018

Acer tegmentosum Maxim (ATM) has been used to treat hepatic disorders in traditional oriental medicine. However, there is little information about phytochemical constituents for quality control of ATM. In this study, we developed and established a simultaneous analytical method of the 10 marker compounds (three coumarins, 3 flavonoids, 1 lignan, 3 phenolics) in ATM using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Chromatographic separation of ten target analytes was achieved with a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$), using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. Identifications and quantitation of all analytes were performed using a Q-Exactive UPLC-MS/MS system. Correlation coefficients of the calibration curve for all analytes were ${\geq}0.9986$. The values of limits of detection and quantification of all analytes were 0.5-10.0 and 5.0-50.0 ng/mL, respectively. The established UPLC-MS/MS method successfully identified all target analytes in ATM, and the phytochemicals were 0.01-67.98 mg/g in its lyophilized water extract.

• Korean Journal of Food Science and Technology
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• v.4 no.1
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• pp.24-28
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• 1972

Synthetic food preservatives were analysed in foods collected in Seoul area on Aug. 10, 1971. Sorbic acid, benzoic acid, dehydroacetic acid and butyl p-hydroxybenzoate were determined by the simultaneous gas chromatography using FID at $200{\circ}C$ and a column of Chromosorb W coated with 5% $DGS{\sim}1%\;H_3PO_4$. The recovery rates of each preservative were from 76.7% to 96.3%. The calibration curves show linearity within a range from 0.3 to $2.5{\mu}g$ of standard preservatives. The results obtained were as follows: 1) Benzoic acid was used as well as butyl p-hydroxybenzoate in soy. 2) Sorbic acid was not found in soy. 3) From all breads and biscuits benzoic acid was found as trace. 4) Detected preservatives were below the range of permitted limit. 5) From 2 soy among 15 samples dehydroacetic acid was found.