• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1625-1625
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• 2001

The calibration equations for Brix value determination of intact mango were developed using the NIR spectra in a short wavelength region from 700 to 1100 nm. Multiple linear regression (MLR) and partial least square regression (PLS) was used for the calibration. It was found that the best wavelength region for PLS calibration from 900 to 1000 nm was similar to the wavelength region selected by MLR from 906 nm to 996 nm. Both MLR and selected region PLS provided sufficiently accurate prediction equations for Brix determination of intact mango. For MLR, the prediction results were SEP = 0.45 Brix and Bias = -0.04 Brix while PLS prediction results were SEP : 0.46 Brix and Bias = -0.2 Brix. It was concluded that MLR and PLS would have similar abilities in making calibration equation for Brix determination of intact mango if the appropriate wavelengths or wavelength region were selected. The appropriate wavelength region for PLS regression could be assumed by using the wavelength region selected by MLR in place of random selection, The relationship between calibration results of MLR and PLS regression is discussed.

• Analytical Science and Technology
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• v.28 no.2
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• pp.125-131
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• 2015

A method was developed and fully validated for the determination of terbutaline, a β₂-receptor agonist, in human plasma. Plasma samples were prepared by solid-phase extraction with Sep-Pak silica, followed by high-performance liquid chromatography (HPLC). The terbutaline was pre-separated from the interfering components in plasma on a Luna C18 (2) column, and terbutaline and salbutamol as an internal standard were resolved and determined on a Luna Silica column. The two columns were connected by a switching valve equipped with silica pre-column. The pre-column was used to concentrate the terbutaline in the eluent from the C18 column before back-flushing onto the silica column with fluorescence detection at an excitation/emission wavelength of 276/306 nm. The method was shown to be specific by testing six different human plasma sources. Linearity was established for a concentration range of 0.4-20.0 ng/mL with a correlation coefficient of 0.9999. The lower limit of quantitation was 0.4 ng/mL with a precision of 10.1% as C.V.%.

• Analytical Science and Technology
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• v.13 no.1
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• pp.34-40
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• 2000

The optimum conditions for the half-life time and residual analysis of the iminoactadine triacetate fungicide on soils were investigated by using the gas chromatography. Iminoctadine triacetate(IOTA) was extracted from soils with 2.0 M-NaOH/methanol and chloroform. The extracted IOTA was derivatized to pyrimidine hexafluroacetylacetone by the acetylation and analyzed with GC/ECD after elimination of moisture and impurities on the Sep-Pak column. From the standard addition experiments with 0.1 and 1.0 ppm, the average recoveries were ranged from 83.8 to 93.2 % and the detection limit was 0.005 ppm. The half-life time of iminoctadine triacetate in the silty clay was 30 days in the laboratory and 19.5 days in the field test whereas it was 27 days and 17.5 days for each in case of silty loam.

• Journal of Korean Academy of Nursing
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• v.33 no.5
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• pp.609-617
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• 2003

Purpose: The purpose of this study is to understand the depression of patients for Fibromyalgia Syndrome(FMS) and to identify the factors influencing depression. Method: The instruments used here are Beck Depression Inventory in depression, the Korean Rheumatology Health Association' instruments in Self-Efficacy. Also, Pain and Fatigue was measured by Visual Graphic Rating Scale. The subject of study is 76 outpatients diagnosing FMS from rheumatism specialists at C hospital in D city. The data has been collected from Sep. 1st to Sep. 30th in 2001. For the analysis of collected data, frequency analysis, independent t-test, analysis of variance, Pearson's correlation and multiple regression analysis were used for statistical analysis with SAS statistical program. Result: General characteristics showing statistically significant difference in depression were age, education, occupation, gender, exercise and sleep in the patients with FMS. Depression for the patients with FMS has negative correlation coefficients with Self-efficacy and ADL, and positive correlation coefficients with Pain and Fatigue. The suitable regression form resulting from the multiple regression analysis to investigate the influencing factors of depression for the partients with FMS was expressed by y =50.067 - 0.278x$_1$ + 1.320x$_2$ (x$_1$: Self-Efficacy x$_2$: Fatigue) and $R^2$ =0.427. Conclusion: The factors influencing on depression of patients for FMS was Self-Efficacy, ADL, Pain, and Fatigue. Further study needs to be done identify methods of overcoming and presentation of depression in FMS.

• Analytical Science and Technology
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• v.8 no.2
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• pp.161-166
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• 1995

Determination of acteoside in Pedicularis resupinata var. oppositifolia has been studied using ion pair liquid chromatography. Sample was extracted with 40mL methanol for 4 hrs. The extract was cleaned up by using Sep-Pak $C_{18}$ catridge and 8mL aqueous methanol eluent(methanol 50%, water 50%, phosphate buffer pH=8.0). Its determination was performed by means of IP-HPLC with a Hamilton PRP-1 polystyrene-divinylbenzene reversed phase column($15cm{\times}4.6mm$ i. d., $5{\mu}m$) and an aqueous methanol eluent(methanol 60%, water 40% phosphate buffer pH=8.2) containing of $5.0{\times}10^{-3}M$ tetrabutylammonium bromide. The established method was applied to the sample that was collected in area of Pyung Chang gun. As a result, its content ranges showed to be 0.062~0.076%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.29-35
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• 2009

The aim of the present study was to update the calibration that is used for the measurement of the total nitrogen content in the rice plant samples by using the visible and near infrared spectrum. Before the equation merge, correlation coefficient of calibration equation for nitrogen content on each rice parts was 0.945 (Leaf), 0.928 (Stem), and 0.864 (Whole plant), respectively. In the calibration models created by each part in the rice plant under the various regression method, the calibration model for the leaf was recorded with relatively high accuracy. Among of those, the calibration equation developed by Partial least squares (PLS) method was more accurate than the Multiple linear regression (MLR) method. The calibration equation was sensitive based on variety and location variations. However, we have merged and enlarged various of the samples that made not only to measure the nitrogen content more accurately, but also later sampling populations became more diversified. After merging, $R^2$ value becomes more accurate and significantly to 0.950 (L.), 0.974 (S.), 0.940 (W.). Also, after removal of outlier, R2 values increased into 0.998, 0.995, and 0.997. In view of the results so far achieved, Standard error of prediction (SEP) and SEP (C) were reduced in the stem and whole plant. Biases were reduced in the leaf, stem as well as whole plant. Slopes were high in the stem. Standard deviation reduced in the stem but $R^2$ was high in the stem and whole plant. Result was indicated that calibration equation make update, and updating robust calibration equation from merge function and multi-variate calibration.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.1
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• pp.46-56
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• 2009

The main purpose of this study was to investigate air quality trends of ambient aerosol with obtaining size-fractionated information. The suspended particulate matters were continuously collected on membrane filters and glass fiber filters by an 8-stage cascade impactor for 2 years (Sep. 2005 $\sim$ Sep. 2007) in Kyung Hee University-Global Campus. 8 ionic species ($Na^+$, ${NH_4}^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$) were analyzed by an IC after performing proper pretreatments of each sample filter. The average concentration levels of each ion were $9.24{\mu}g/m^3$ of ${SO_4}^{2-}$, $7.35{\mu}g/m^3$ of ${NO_3}^-$, $2.81{\mu}g/m^3$ of ${NH_4}^+$, $2.11{\mu}g/m^3$ of $Ca^{2+}$, $1.65{\mu}g/m^3$ of $Cl^-$, $1.87{\mu}g/m^3$ of $Na^+$, $0.80{\mu}g/m^3$ of $Mg^{2+}$, and $0.54{\mu}g/m^3$ of $K^+$, respectively. The distribution pattern of $Na^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${NO_3}^-$ was bi-modal and two peaks appeared in the range of $0.4{\sim}0.7{\mu}m$ and $3.3{\sim}4.7{\mu}m$, respectively. On the other hand, ${SO_4}^{2-}$, ${NH_4}^+$, and $K^+$ showed patterns of uni-modal distribution, mostly abounded in the fine mode group.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.153-159
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• 1998

A possibility of evaluation of the major internal quality factors-Brix, moisture contents, firmness and acid content in the Korean domestic 'Fuji'apple fruits by near-infrared reflectance spectroscopic (NIRS) methods were investigated. A multiple linear regression(MLR) analysis between the data obtained by physico- chemical analysis method using refractometer, freeze drier, texture analyzer and titrater and NIR spectral data was carried out to make a calibration. The standard error of prediction(SEP) of Brix, moisture, firmness and acid content were $0.50^{\circ}Brix,\;0.64%,\;0.14kg/cm^2$ and 0.07%. It is concluded that NIRS methods can be used to evaluate Brix and moisture contents of in a apple non-destructive and rapid way but the accuracy for determination of firmness and acid content was slightly low.

• Food Engineering Progress
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• v.15 no.1
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• pp.48-55
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• 2011

In this research, the near-infrared absorption from 1,100-2,300 nm was used to measure the content of capsaicinoids in the red-pepper powder by using the Acousto-optic tunable filters (AOTF) spectrometer with sample plate and sample rotating unit. Non-spicy red-pepper samples from one location (Younggwang-gun. Korea) were mixed with spicy one (var. Chungyang) to make samples separated by particle size (below 0.425 mm, 0.425-0.71 mm, and 0.71- 1.4 mm). The Partial Least Squares Regression (PLSR) model to predict the capsaicinoid content on particle sizes was developed with measured spectra by AOTF spectrometer and used to analyze the amount of capsaicinoids by HPLC. The PLSR Model of red-pepper powder of below 0.425 mm, 0.425-0.71 mm, and 0.71-1.4 mm with cross validation had ${R_V}^2$ = 0.948-0.979 and Standard Error of Prediction (SEP) = 6.56-7.94 mg%. The prediction error of smaller particle size of red-pepper powder was low. The best PLSR model was found in pretreatment of Range Normalization, Standard Normal Variate, and 1st Derivatives of red-pepper powder of below 1.4 mm with cross validation, having ${R_V}^2$ = 0.959 and SEP = 8.82 mg%.

• Journal of the Korean Society of Tobacco Science
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• v.35 no.1
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• pp.1-6
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• 2013

Near InfraRed Spectroscopy(NIRS) is a quick and accurate analytical method to measure multiple components in tobacco manufacturing process. This study was carried out to develop calibration equation of near infrared spectroscopy for the prediction of the amount of chemical components and hot water solubles(HWS) of reconstituted tobacco leaf. Calibration samples of reconstituted tobacco leaf were collected from every lot produced during one year. The calibration equation was formulated as modified partial least square regression method (MPLS) by analyzing laboratory actual values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with the standard error of prediction(SEP) of chemical components in reconstituted tobacco leaf samples, indicated as coefficient of determination($R^2$) and prediction error of sample unacquainted, followed by the verification of model equation of laboratory actual values and these predicted results. As a result of monitoring, the standard error of prediction(SEP) were 0.25 % for total sugar, 0.03 % for nicotine, 0.03 % for chlorine, 0.16 % for nitrate, and 0.38 % for hot water solubles. The coefficient of determination($R^2$) were 0.98 for total sugar, 0.97 for nicotine, 0.96 for chlorine, 0.98 for nitrate and 0.92 for hot water solubles. Therefore, the NIRS calibration equation can be applicable and reliable for determination of chemical components of reconstituted tobacco leaf, and NIRS analytical method could be used as a rapid and accurate quality control method.