• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1114-1119
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• 1998

The stabilities of O/W emulsions (lipophilic core material:lipophobic wall material=3:2, w/w) containing various kinds of emulsifiers were compared to determine the optimal conditions of the HLB (hydrophilic lipophilic balance) value, the concentration and composition of emulsifier, the ratio of core material to the wall material, and the concentration and composition of polymers in the wall material. The effect of different chemical types of emulsifiers and the influence of single vs. binary emulsifier systems were compared with 13 kinds of emulsifier HLB values of $0.6{\sim}16.7$ at the concentration of 0.50%(w/w). The emulsion system was stable (more than 99.0 of ESI value) when the HLB value of the emulsifier was more than 11.0 or less than 2.8 of emulsifier HLB value. But it was unstable (less than 40.0 of ESI value) at the HLB value of the emulsifier between 3.4 and 8.6. Especially, we could find out the emulsion containing the emulsifier of polyglycerol polyricinoleate (PGPR, HLB 0.6) became stable creamy state. And, the ESI value of binary emulsifier system containing 0.25%(w/w) of PGPR and 0.25%(w/w) of polyoxyethylene sorbitan monolaurate (PSML, HLB 16.7) was higher than that of any single emulsifier system at the concentration of 0.50%(w/w). The highest emulsion stability was obtained in the liquefied wall material composed of 0.25%(w/v) of waxy corn starch and 0.50%(w/v) of agar.

• Analytical Science and Technology
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• v.13 no.4
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• pp.504-510
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• 2000

The impurity profiles from the raw materials of glycyrrhizin were performed by the high performance liquid chromatography (HPLC)/electrospray ionization (ESI)- mass spectrometry (MS). For the HPLC experiment, a $C_{18}$($3.9{\times}300mm$, $10{\mu}m$) column was used and the mobile phase was acetic acid/$H_2O$ (1:10):acetonitrile=3:2 with a flow rate of 0.8 ml/min. The effluent was splitted into the ratio of 50:1 and went into the ESI-MS. Three to six impurities were found and informed of the identification of the structure of the impurities by ESI-MS. And the structures of impurities were suggested to a hydroxy-glycyrrhizin which is added with hydroxy group (-OH) in the glycyrrhetic acid moiety and a reduced-glycyrrhizin which the position of 12 of the glycyrrhetic acid moiety is reduced. The purities of the standard materials were about 90%.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.46-54
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• 2022

Known for its effectiveness in weight loss and diabetes prevention, Gymnema sylvestre products can be found in the US, Japanese, and Indian markets. However, the recommended dosage or safety of these products has not yet been proven. Therefore, development of an analytical method for detecting the content of Gymnema sylvestre in food products is required. Accordingly, this study proposes an analysis method that can examine Gymnema sylvestre in food using LC-ESI-MS/MS and KASP (Kompetitive Allele-Specific PCR) markers. In LC-ESI-MS/MS, a simultaneous analysis method for gymnemic acid and deacylgymnemic acid was optimized using negative ionization mode, and its validation test was completed for solid and liquid samples. In addition, KASP markers were prepared by finding the specific SNP of G. sylvestre in ITS2 and matK through DNA barcodes. The two KASP markers returned positive FAM fluorescence result when combined with G. sylvestre, and this aspect was confirmed in raw G. sylvestre as well. The applicability of the method was tested on 21 different food and healthy functional products containing G. sylvestre purchased on the internet. As a result, although there was a difference in the ratios of gymnemic acid and deacylgymnemic acid in LC-ESI-MS/MS, the index component was detected in all 21 products samples. In the KASP analysis, 9 products returned positive FAM result, and the rest of the products were found to be containing G. sylvestre extract. This study is the first study to use the dual system of LC-ESI-MS/MS and KASP for the analysis of G. sylvestre. The study has confirmed that these two methods are applicable to the examine G. sylvestre content in food products.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.63-73
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• 2020

Drought is considered as a devastating hazard that causes serious agricultural, ecological and socio-economic impacts worldwide. Fundamentally, the drought can be defined as temporarily different levels of inadequate precipitation, soil moisture, and water supply relative to the long-term average conditions. From no unified definition of droughts, droughts have been divided into different severity level, i.e., moderate drought, severe drought, extreme drought and exceptional drought. The drought severity classification defined the ranges for each indicator for each dryness level. Because the ranges of the various indicators often don't coincide, the final drought category tends to be based on what the majority of the indicators show and on local observations. Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used as a index of the droughts occurring rapidly in a short period of time from studies showing a more sensitive and fast response to drought compared to Standardized Precipitation Index (SPI), and Palmer Drought Severity Index (PDSI). However, ESI is difficult to provide an objective drought assessment because it does not have clear drought severity classification criteria. In this study, U.S. Drought Monitor (USDM), the standard for drought determination used in the United States, was applied to ESI, and the Percentile method was used to classify drought categories by severity. Regarding the actual 2017 drought event in South Korea, we compare the spatial distribution of drought area and understand the USDM-based ESI by comparing the results of Standardized Groundwater level Index (SGI) and drought impact information. These results demonstrated that the USDM-based ESI could be an effective tool to provide objective drought conditions to inform management decisions for drought policy.

• Analytical Science and Technology
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• v.17 no.2
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• pp.117-129
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• 2004

Amitrole in environment, difficult to be analyzed by GC or GC/MS due to high polarity and low volatility, was analyzed by LC/ESI/MS in the study. Maximum peak intensity of amitrole in LC/MS/ESI mass spectrum is m/z 85 of protonated molecular ion $(M+H)^+$ with 30V of cone voltage at SIR mode. It was confirmed that ratios between main ion of amitrole, 85 of protonated molecular ion, and m/z 58 fragmented ion of amitrole, had increased corresponding with the increment of cone voltage from 20V to 70V. The isotope molecular weight of amitrole was $86([M+H])^+$ at LC/MS analysis and the mass spectrum ratio between 85 mass and 86 mass was not different by the change of concentration but similar to theoretical ratio(less than 10% standard deviation).The linearity of standard calibration curve under same condition with sample treatment method had $y=1.09354e^6X+26947.2$ and $r^2=0.99$. Recovery rates in water and soil samples were 77.64~83.44% and 71.11~79.44%, respectively. Reliability of the analysis was performed with 5 repeated measurements at each level of standard concentration and the result showed that relative standard deviation was less than 10%; therefore, the extraction and analysis method in the study suggested that it would be reliable to measure amitrole in water and soil media.

• CELLMED
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• v.11 no.3
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• pp.13.1-13.9
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• 2021

Background and Objective: Nux-vomica based traditional Unani formulation, Habb-e-Azaraqi (HAZ) is an important drug used by Unani physicians since several decades. It possesses Muqawwi-i-A'sab (nervine tonic), Muharrik-i-A'sab (nervine stimulant) properties and is an effective treatment option for diseases like Laqwa (facial palsy), Falij (paralysis), Niqris (gout) and Waja'al-Mafasil (arthritis) etc. The aim of the study is to access and provide information of HAZ for its TLC, HPTLC Fingerprinting defining its clear qualitative perspective and acute oral toxicity evaluation for its safety assessment which was not done earlier, thus contributing in the field of research. Materials and Methods: The chief ingredient, nux-vomica was detoxified as per method mentioned in Unani Pharmacopeia before its use in formulation. TLC and HPTLC was developed under four detection system i.e., UV 366nm, UV 254nm, exposure to iodine vapours and after derivatization with anisaldehyde sulphuric acid. Acute toxicity studies were performed as per OECD Guidelines 425 at a limit dose of 2000 mg/kg. Observations were done for signs of toxicity, body weight, and feed consumption at regular intervals followed by haematological and biochemistry evaluation. Results: The generated data proved the authenticity and established the TLC and HPTLC profile of the formulation. Acute toxicity revealed no significant differences in HAZ-treated animals with respect to body weight gain, feed consumption, haematology, clinical biochemistry evaluation. No significant gross pathological observation was noticed in necropsy. Conclusion: Data of the present study is substantial and scientific proof of HAZ in terms of standardization and toxicity study that can be utilize in future research activities.

• Analytical Science and Technology
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• v.21 no.6
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• pp.535-542
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• 2008

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed for the determination and confirmation of clenbuterol in bovine muscle and milk. Clenbuterol and clenbuterol-D9 using as an internal standard in samples were extracted with ethyl acetate after hydrolysis and evaporated to dryness. The extracts were dissolved in 20% methanol and cleaned using HLB solid-phase extraction cartridge. The analytes were detected by LC-ESI/MS/MS on a $C_{18}$ column. Mass spectral acquisition was done in selected reaction monitoring (SRM) in positive ion mode to provide a high degree of sensitivity. Using MS/MS with SRM mode, the transitions (precursor to product) monitored were m/z 277${\rightarrow}$203 for clenbuterol, and m/z 286${\rightarrow}$204 for internal standard. The limits of quantitation (LOQ) and mean recoveries of clenbuterol in bovine muscle were $0.2{\mu}g/kg$ and 84.3~91.1%, respectively. The LOQ and mean recoveries in milk were $0.05{\mu}g/kg$ and 87.7~98.3%, respectively.

• Natural Product Sciences
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• v.14 no.3
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• pp.152-155
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• 2008

An HPLC-ESI-MS method has been developed to identify and quantify two main tetracyclic triterpenes, alisol B 23-acetate and alisol C 23-acetate in the Alismatis Rhizoma (Taeg-Sa). The relative distribution of the two triterpenes in the methanolic extract of commercially available Alismatis Rhizoma was established by selective ion monitoring (SIM) mode via electrospray ionization (ESI) source. Regression equations revealed good linear relationship, and the correlation coefficients were 0.999 and 0.998 for alisol B 23-acetate and alisol C 23-acetate, respectively, between the peak areas of the components and their concentration in a range of $0.06-2.0{\mu}g/mL$. It was found that there were significant differences in the amount of alisol B 23-acetate and alisol C 23-acetate between Korean and Chinese origins. The results showed that this method could be used to identify the two components in Alismatis Rhizoma with high sensitivity and selectivity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.563-564
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• 2014

Recent developments in the prediction of the contribution of windnoise to the interior SPL have opened a realm of new possibilities in terms of i) how the convective and acoustic sources terms can be identified, ii) how the interaction between the source terms and the side glass can be described and finally iii) how the transfer path from the sources to the interior of the vehicle can be modelled. This work discusses several simulation methods that can be used to represent the physical phenomena involved such as CFD, FEM, BEM, FE/SEA Coupled and SEA. This work focuses on the validation of the wind noise source characterization method and the vibro-acoustic models on which the wind noise sources are applied in the framework of a benchmark proposed by Hyundai Motors Corporation.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.846-849
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• 2008

This study employed high performance liquid chromatography (HPLC) coupled to an on-line $ABTS^+$ radical scavenging detection (RSD) system along with HPLC-electro spin impact/mass spectrometry (ESI/MS), to rapidly determine and identify antioxidant compounds occurring in blueberry extract. The extract was separated by HPLC, and then the radical scavenging activities of the separated compounds were evaluated by the on-line coupled $ABTS^+$-RSD system. The negative peaks of the $ABTS^+$-RSD system, which indicates the presence of antioxidant activity, were monitored by measuring the decrease in absorbance at 734 nm. The active components in the blueberry extract were identified by HPLC-ESI/MS using their MS spectra and retention times. According to the data acquired from the on-line HPLC-$ABTS^+$-based assay and HPLC-ESI/MS systems, the antioxidant compounds detected in the blueberry extract were identified as chlorogenic acid and 11 anthocyanins.