• 대한본초학회지
• /
• 제23권1호
• /
• pp.109-116
• /
• 2008

Objectives : This study was performed to investigate the discriminative criteria of 6 kinds of Achyranthis Radix by HPLC/DAD. Methods : 20-hydroxyecdysone is isolated by silica gel column chromatography ($CHCl_3$:MeOH, 7:1-1:1 v/v) and identified by nuclear magnetic resonance, A high-performance liquid chromatographic method with diode array detection was used to identify 20-hydroxyecdysone in A. japonica. The analysis was performed using $C_{18}$ column with isocratic elution consisted of 18% acetonitrile and 82% water and the detection was carried out by DAD at 254 nm. 6 kinds of Achyranthis Radix from different locations were extracted in MeOH. Each extracts was analyzed by HPLC in same condition as used in analysis of 20-hydroxyecdysone. The identities of each extracts were determined by comparing the retention time and UV spectrum with that of reference compound. Results : 1. A. japonica and A. bidentata showed the similar patterns of HPLC chromatogram and 20-hydroxycedysone was present in both of them because the peaks having the same retention time and UV spectrum as 20-hydroxyecdysone were shown in the HPLC chromatograms of A. japonica and A. bidentata 2. Cyathula officinalis and C. capitata showed the similar patterns of HPLC chromatogram. The peak having the same retention time and UV spectrum as 20-hydroxyecdysone was shown in the HPLC chromatogram of C. capitata but not shown in the HPLC chromatogram of C. officinalis. 3. Two species of medicinal drugs from Sacheon province showed similar patterns of HPLC chromatogram. Achyranthis Radix from Sacheon(wild) did not have 20-hydroxycedysone but Achyranthis Radix from Sacheon(cultivated) showed the peak having the same retention time as 20-hydroxyecdysone but UV spectrum of the peak was different from that of 20-hydroxyecdysone. Conclusions : These results suggested that 20-hydroxyecdysone could be the discriminative criteria for Achyranthis Radix contain 20-hydroxyecdysone though they belong to different genus and species. And the patterns of HPLC chromatogram also could be the discriminative criteria as the different species of Achyranthis Radix belonging to the same genus showed similar patterns of HPLC chromatogram.

• 한국수산과학회지
• /
• 제30권3호
• /
• pp.377-387
• /
• 1997

해수로 유출되고 있는 유기인제 살충, 살균제의 형광 분석법에 의한 finger print식 분석 방법을 개발하기 위해, 벼 농사에 가장 많이 사용되어지는 Hinosan과 Kitazin을 포함하는 10가지의 표준 용액을 조제하여, 형광 특성을 측정하였다. $220nm\~520nm$ 구간의 흡수 파장을 이용하여, 여기 (excitation)시켜 얻은 형광스펙트럼들을 이차원 평면 위의 형광세기 표시를 등고선 모양으로 표시하였다. 이 contour들은 각 조사된 유기인제에 대해 특징적인 형태로 관찰되었다. 조사된 10가지의 유기인제 농약의 형광 contour들은, 봉우리가 한 개로 된 DDVP를 포함한 8가지의 유기인제와 두 개의 봉우리로 나타난 Ateric을 포함한 두 가지의 유기인제 농약으로 나뉘어진다. 또한 최대 흡수파장의 영역별로 보면, 단일한 봉우리를 보이는 많은 유기인제는 약 280nm에, Ateric을 포함한 두 종류의 유기인제는 260nm에서, 그리고 장파장에서 최대 형광파장을 보여준 Monopho, Thaconyl의 최대 흡수파장은 비교적 장파장쪽으로 치우친 300nm와 340nm인, 다른 유기인제의 최대 형광파장과 서로 겹치지 않는 영역에서 나타났다. 그러나, 280nm에서 최대 흡수파장을 나타내는 유기인제 중에 Kitazin, Locsion, Meta는 약 2nm이하의 근소한 차이를 두고 최대 형광세기를 308nm주변에서 나타내었다. 이러한 그룹의 분별을 위해, HPLC-형광 자료를 이용하면 용리시간 차이에 의한 분리와 identification이 가능했다. 형광 contour가 매우 유사한 Kitazin, Locsion과 Meta를 비교하면, Kitazin은 $16\~20$분 대에 나타나는 peak들이 매우 미약할 뿐 아니라, 용리시간 9.6분에 나타난 현저한 단일 peak가 다른 형광 특성이 비슷한 유기인제인 Locsion이나 Meta와의 구분이 용이하게 해 준다. 그러나, Locsion과 Meta는 chromatogram의 용리시간이나, 세부적인 작은 peak 특징은 다르나, 그 pattern이 유사하여, 분석상 불확실성이 내재될 가능성이 있다.

• Journal of Mechanical Science and Technology
• /
• 제16권12호
• /
• pp.1604-1612
• /
• 2002

Rollers in the continuous process systems are ones of key components that determine the quality of web products. The condition of rollers (e.g. eccentricity, runout) should be consistently monitored in order to maintain the process conditions (e.g. tension, edge position) within a required specification. In this paper, a new diagnosis algorithm is suggested to detect the defective rollers based on the frequency analysis of web tension signals. The kernel of this technique is to use the characteristic features (RMS, Peak value, Power spectral density) of tension signals which allow the identification of the faulty rollers and the diagnosis of the degree of fault in the rollers. The characteristic features could be used to train an artificial neural network which could classify roller conditions into three groups (normal, warning, and faulty conditions) The simulation and experimental results showed that the suggested diagnosis algorithm can be successfully used to identify the defective rollers as well as to diagnose the degree of the defect of those rollers.

• Mass Spectrometry Letters
• /
• 제6권4호
• /
• pp.105-111
• /
• 2015

Sixteen compounds of Neobalanocarpus heimii were successfully identified directly from their plant extract using a triple quadrupole LC-MS/MS system. In order to fulfil the objectives of this work, a series of stilbene oligomers of various degrees of condensation were isolated and their structure are characterized. Out of these, four are resveratrol dimers, three trimers, and nine tetramers. The isolation process was done on a fully automated semi-preparative HPLC system. Their structures were elucidated on the basis of 1D- and 2D-NMR as well as MS data. The mass fragmentation patterns of the compounds were recorded and a retrievable in-house library was built to keep the data. In order to demonstrate the potential of this approach, the polyphenolic crude extract was analysed with the LC-MS/MS system and the MS/MS spectra extracted for each chromatographic peak of interest. The fragmentation patterns were compared with those of anticipated pure compounds that were previously recorded. All compounds were successfully identified. It is therefore believed that the LC-MS/MS potential for dereplication of structurally similar compounds in a crude mixture was thus firmly established.

• Fibers and Polymers
• /
• 제5권3호
• /
• pp.198-203
• /
• 2004

Composite films were prepared by casting the solution of polyacrylonitrile (PAN) and single wall nanotube (SWNT) in DMF subsequent to sonication. The SWNTs in the films are well dispersed as ropes with 20-30 nm thickness. Moreover, AFM surface image of the composite film displays an interwoven fibrous structure of nanotubes which may give rise to conductive passways and lead to high conductivity. The polarized Raman spectroscopy is an ideal characterization technique for identification and the orientation study of SWNT. The well-defined G-peak intensity at 1580 $cm^{-1}$shows a dependency on the draw ratio under cross-Nicol. The degree of nanotube orientation in the drawn film was measurable from the sine curve obtained by rotating the drawn film on the plane of cross-Nicol of polarized Raman microscope. The threshold loading of SWNT for electrical conductivity in PAN is found to be lower than 1 wt% in the composite film. The electrical conductivity of the SWNT/PAN composite film decreased with increasing of draw ratio due to the collapse of the interwoven fibrous network of the nanotubes with uniaxial orientation.

• Archives of Pharmacal Research
• /
• 제24권5호
• /
• pp.407-411
• /
• 2001

Reversed-phase high performance liquid chromatographic method was applied for the determination of eleutheroside B and E in the various Acanthopanax species collected In Korea. The stationary phase used was Zorbax 300 SB $C_{18}$ and a mobile phase program was used, which started at 6% acetonitrile for 2 min, and then a linear gradient was operated for the next 18 min to 17% acetonitrile at a flow rate of 1.0 ml/min. The column effluent was monitored at UV 210 nm. Identification was carried out by comparing the retention time and the LC/MS spectrum of each peak corresponding to eleutheroside B and E from sample with those of standards. In general, the contents of eleutheroside B and 1 in stems were higher than those In roots. Acanthopanax species could be classified into two groups based upon the contents of eleutheroside B and E: one group contains no or very little eleutheroside B and another contains both eleutheroside B and E.

• 생약학회지
• /
• 제43권3호
• /
• pp.250-256
• /
• 2012

In order to extract the curcuminoid such as curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) in turmeric (Curcuma longa), solvent extraction methods (dipping and ultrasonic extraction method) and solid-phase extraction (SPE) were used. RP-HPLC (reverse-phase high-performance liquid chromatography) and TLC (thin-layer chromatography) were used for identification and analysis the three curcuminoid. From the experimental results, it is evident that the percentage of curcuminoid extracted from turmeric by ultrasonic extraction method was higher than dipping method. The percentage of curcumin extracted from turmeric by pure methanol was higher than any aqueous methanolic composition. Moreover, the total peak area of three curcuminoid was above 92% in RP-HPLC using solid-phase extraction. These results will form a database for investigating the constituents of natural products and the resources of pharmaceutical, nutrition, and cosmetic products.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 춘계학술대회논문집
• /
• pp.633-638
• /
• 2002

The vacuum cleaner that has no dust bag generates very high level annoying noise. The dominant noise source is the 2$\^$nd/ BPF tone of the rotating impeller. In order to reduce the noise, we identify the acoustic characteristics and reduce the noise of the vacuum cleaner and centrifugal fan. The resonance phenomenon is observed in blade passages and we found out that the resonance frequency is very close to the 2$\^$nd/ BPF. In order to reduce this high-level peak noise, new impeller is designed in this paper. The trailing edge of new impeller is inclined and this makes the flow interactions between the rotating impeller and the stationary diffuser vane occurs with some phase shift. The performance of new impeller is similar to the old one but the overall SPL is reduced about 3.6dBA. The SPL of BPF is reduced about 6dBA and 2$\^$nd/ BPF is reduced about 20dBA. The vacuum cleaner, which uses newly developed centrifugal fan, generate more comfortable noise than the old model and the strong tonal sound was dramatically reduced.

• Natural Product Sciences
• /
• 제23권4호
• /
• pp.247-252
• /
• 2017

The methylglyoxal (MGO) trapping constituents from onion (Allium cepa L.) peels were investigated using pre-column incubation of MGO and crude extract followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Among major constituents in outer scale of onion, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2) was more effective MGO scavenger than quercetin (6) and its 4'-glucoside, spiraeoside (3). After 1 h incubation, compound 2 trapped over 90% MGO at a concentration of 0.5 mM under physiological conditions, but compounds 3 and 6 scavenged 45%, 16% MGO, respectively. HPLC-ESI/MS showed that compound 2 trapped two molecules of MGO to form a di-MGO adduct and compounds 3 and 6 captured one molecule of MGO to form mono-MGO adducts, and the positions 6 and 8 of the A ring of flavonoids were major active sites for trapping MGO.

• 한국식생활문화학회지
• /
• 제16권4호
• /
• pp.354-360
• /
• 2001

A Lactic acid bacterium for barley bread was isolated from barley powder and was identified as Enterococcus sp. It was used as a starter for barley bread and quality of bread was compared with the bread prepared by conventional starter 1. The pH of bread making process using Lactobacillus sanfrancisco starter was the lowest among tested starters. while the titratable acidity(TTA) of the strain was the highest, followed by Enterococcus sp.. 2. In valorimeter value(v/v), control was 70, but dough using all starter was 60. The peak time and stability of dough using Lactobacillus sanfrancisco were the highest among tested starters. 3. Extensibility of dough using Enterococcus sp. was the highest among tested starters, followed by Lactobacillus sanfrancisco. Proper extensibility and maximum resistance were observed in Lactobacillus sanfrancisco.