• Mass Spectrometry Letters
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• v.11 no.4
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• pp.71-76
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• 2020

While montelukast (ML), a cysteinyl-leukotriene type 1 receptor (CysLT1) antagonist is widely used to treat symptoms of rhinitis or asthma, its formulations are mainly limited to solid preparation due to its instability. Recently, there have been attempts to develop various ML dosage forms, and this situation increases the demand of sensitive and creditable methods to determine ML in various samples such as plasma. Thus, here, a simple and efficient method to determine ML in rat plasma using liquid-liquid extraction (LLE) and multiple reaction monitoring was presented. The mixture of DCM:EtOAc (25:75, v/v), the optimized extract solvent for LLE was found to be effective to extract ML without hydrophilic salts and proteins from the sample with limited volume. Also, the use of zafirlukast, instead of expensive ML-d6, as the internal standard makes the present method economical. The developed method was successfully validated in terms of selectivity, matrix effects (-14.8--6.9%), linearity (r230.998 within 0.5-500 ng/mL), sensitivity (the limit of detection and the lower limit of quantitation, ≤0.5 ng/mL), accuracy (88.4-100.6%), precision (3.0-13.3%), and recovery (80.8-86.3%) by following the FDA guidelines. Finally, the applicability of the validated method to pharmacokinetics (PK) studies was confirmed by the successful determination of PK parameters through it following oral administration of Singulair® granule in rats. Therefore, the present method can contribute to the development of new ML formulations through its performance to determine ML in rat plasma efficiently and sensitively.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.197-203
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• 2021

Saponarin is a crucial component of barley sprout, and the production and quantitative analysis are issued to date. In this study, the optimal saponarin extraction conditions were presented on the subject of acetonitrile, ethanol, methanol, and water for the quantitative analysis in barley sprout through the extraction efficiency compared with the solvent concentration and extraction time using the reaction surface methodology. The optimal extraction time and solvent condition for saponarin were 3.9 h and 53.7% of aqueous methanol, respectively. In addition, the effect of LED artificial light on the saponarin production in barley sprouts was evaluated by the light cycle, light quantity, and light quality. The optimal cultivation conditions under artificial light for the growth of barley sprout and saponarin production were most effectively achieved on 220-320 μmol m^-2 s^-1 of the light quantity with 8 h day^-1 of a daylight cycle under 6500K LED combined with red light. Furthermore, blue light was evaluated as the main factor in the biosynthesis of saponarin.

• Journal of the Korean Society of Food Culture
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• v.7 no.1
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• pp.19-23
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• 1992

Jindo Hongju is a traditional liquor in Jindo island of Korea. The characteristics of Hongju are its unique flavour by fermetation and red color of gromwell(Lithospermum erythrorhizon) root. However, the evaluation of red pigment is different from one manufactures to other manufactures and from place to place, also the standard method is not established. An attempt has made to compare the quality of gromwell root from different places and to standardize the extracting method. The results obtained from this study are summerized as follow, The chemical properties and composition of gromwell root from Jindo and other areas were compared. There were no difference among the samples in moisture content, content of naphtoquinone derivatives and absoption spectra. These results indicate that the pigments from Jindo and other region products seems to be the same quality. For efficient extraction of gromwell pigment, more than 40% ethanol as solvent and at least 10 hours extraction time was required. According to the visual test for Hongju pigment, the most preferable color was that it shows absorbance of 1.0 (contents of shikonin was 3.90 mg/45% EtOH 20 ml). From this visual test it can be proposed that the may be applied absorbance at 1.0 for the quality control of pigment.

• YAKHAK HOEJI
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• v.28 no.2
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• pp.61-67
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• 1984

A method is described for the spectrophotometric determination of platinum (IV) with 2-oximino-1-indanone based on solvent extraction of Pt:2-oximino-1-indanone complex. The 2-oximino-1-indanone reacted with Pt(IV) to form a dark-orange complex which shows a characterisic maximum absorption at 342nm. The optimum PH for the platinum extraction lies between 5.4~8.0. Beer's law obeys up to 0.98-16.3ppm of platinum (IV) and the molar absorption coefficient is $1.06{\times}10^{-4}L.mol^{-1}.cm^{-1}$. The relative standard deviation of the method was $\times2.1%$. The composition of the complex is estimated to be Pt : In= 1 : 1, by the mole ratio method and ion exchange resin experiment. The optimum condition for the determination of platinum has been studied in detail. The 2-oximin-1-indanone is found to be a selectivereagent for the determination of platinum, since the synthesixed 2-oximino-1-indanone did not react with other metals such as cobalt, cadmium, copper, manganese nickel, iron, lead and zinc, to form the complex. In this studies, we have also clarified Sindhwani and Singh's spectrophotometric determination data of various metals with acenaphthenequinone monooxime (Talanta 20,248, 1973), whose results were not correct.

• Analytical Science and Technology
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• v.24 no.5
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• pp.352-359
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• 2011

An analytical method for solvent-free determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in water using repetitive membrane extractions coupled to cryofocusing and GC-MS was derived. BTEX compounds that permeated through a nonporous silicone membrane from the aqueous phase and evaporated into the acceptor phase were purged into a cryofocusing trap ($-100^{\circ}C$) with helium gas. The BTEX compounds, thus enriched in the trap, were thermally desorbed into a capillary column GC and detected using an MS. The flow rate of the donor phase (30 mL water) was set at 10 mL/min, and membrane extractions, accomplished by returning the water drained from the extraction module to the sample container, were repeated three times at $20{\pm}2^{\circ}C$. Although recoveries (%) were variable, from the highest for benzene (approximately 80%) to the lowest for ethylbenzene and xylenes (3.5-10%), the method showed satisfactory precision (RSD 2.2-10%) with good-linearity calibration curves ($r^2$ 0.9976-0.9997 in 1-100 ${\mu}g$/L range) for all of the compounds. The method detection limits (MDLs) ranged from 0.16 to 1.8 ${\mu}g$/L. The results showed the method's advantages such as short analysis time and overall simplicity without solvent compared to the conventional techniques.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.566-569
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• 2005

A novel purification method was developed for producing homoharringtonine from Cephalotaxus koreana, to guarantee high purity and yield. Our simple, efficient procedure for isolating and purifying homoharringtonine from C. koreanabiomass consisted of solvent extraction, synthetic adsorbent treatment, low-pressure chromatography, followed by high performance liquid chromatography (HPLC). The use of active clay treatment and silica gel low-pressure chromatography in the pre-purification process allowed for the rapid, efficient separation of homoharringtonine from interfering compounds and dramatically increased the yield and purity of crude homoharringtonine for high-performance liquid chromatography (HPLC) purification steps compared with alternative processes. Homoharringtonine could be obtained simply with high yield and purity from biomass using this purification method, while minimizing solvent use and the scale and complexity of HPLC operations for homoharringtonine purification. Purified homoharringtonine was identified and characterized.

• Resources Recycling
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• v.7 no.2
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• pp.9-15
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• 1998

Recovery af molybdenum in spent desulfuriring catalyst of petrochemical industries was studied from MfGnatc solulion which is a resultant of firstly remvercd vanadium by wet processes. In order to separate and recover molybdenum from upper mentioned rafinatz solution containing several mctal ions, such as molybdenum (1,100 ppm), vanadium (150 ppm), aluminium (19 ppm), and nickel (33 ppm), either adsorption technique by chelate resin or solvent extr~ction by tertiary amine as extractant was applied. In case of adsorption method, palyamine type chelate resin showed the highest selectivily far molybdenum ion up lo 60 ddm' of ancentration aftcr eluting with 3.0 rnolld~n' of NH,OH. On the othcr hand. molybdenum ion wa cffectlvely cxtractcd in Ule whole ranges of equilibrilrm pR by solvent extraction method with 10 ~01%-alamine 336 which was pretreated with 2N-HCI

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.151-162
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• 1977

Distribution of marine algae is diverse in Korea and the resource of edible algae is abundant marking 239,037 tons of yearly production in 1976. They have been known as a protein source and used as a supplement in Korean diet. It is necessary to estimate the potentiality and properties of usable algal proteins especially as food resources and studies of extraction and separation of the proteins, therefore, are basically required for this purpose. In this study, the influence of various factors including the sample treatment, extraction time and temperature, sample us extraction solvent ratio and pH upon the extractability of the water soluble protein was determined. And the effect of precipitation treatment for isolation of the algal protein from the extracts was also tested. Nine species of algae, the major ones in consumption as food namely Porphyra suborbiculata, Undaria pinnatifida, Hizikia fusiforme, Sargassum fulvellu, Enteromorpha linza, Codium fragile, Sargassum kjellmanianum and Ulva pertusa were collected as fresh from Kijang, Yangsan Gun, in the vicinity of Busan city. The content of crude protein $(N\times6.25)$ of the algae ranged from $9.46\%\;to\;24.14\% showing the highest value in Porphyra suborbiculata and the minimum in Hizikia fusiforme. In the effort of maceration of blending methods on the extractability, immersion freezing in dry ice-methanol solution appeared most effective yielding 1.5 to 2.5 times extractability than that of the mortar grinding method. The effect of the ratio of sample vs solvent on extractability differed from species. It was enhanced at the ratio of 1:20 (w/v) in Ulva pertusa and Enteromorpha linza while the ratio was 1:30 (w/v) for Cedium fragile, Undaria pinnatifida, Hizikia fusiferme, Sargassum fulvellum and Porphyra suborbiculata and 1:40 for Sargassum kjellmanianum respectively. The effect of extraction time and temperature was revealed differently from species which might be caused by differences in the constitution of algal tissues resulting in that the extraction for 1 hour at $50^{\circ}C$ gave the maximum extractabilily in Ulva pertusa and Enteromorpha linza, 2 hours in Porphyra suborbiculata, Hikikia fusiforme, Undaria pinnatifida, Sargassum kjellmanianum and 3 hours in Codium fragile. And the extractability was higher at $50^{\circ}C$ to $60^{\circ}C$ for the most of the tested samples except Hizikia fusiforme. The optimum pH for the extraction was 9 to 12. The recovery of extractable nitrogen to the total nitrogen was $63\%$ in average with the first extracts and $8.6\%$ with the second extracts respectively. Both extracts were prepared by 2 hour extraction at $50{\pm}1^{\circ}C$ with dry ice-methanol frozen and seasand macerated materials. And these conditions assumed to be an optimum for the extraction of water soluble algal proteins since the nitrogen content after the first extraction covered $90\%$ of the total water extractable nitrogen. In the precipitation of the extracted proteins, Barnstein method and methanol treatment seemed to be more efficient than other precipitation methods.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.140-148
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• 2008

We compared the quality and quantity of volatile components in salt-dried croakers prepared by different methods and obtained from different locations. In total, 110 compounds were found among regular- and delay-type salt-dried croakers purchased from two locations in Hong Kong. The major chemical classes included miscellaneous compounds(17), pyrazines(16), alcohols(15), and sulfur-containing compounds(13). Fish obtained in different locations but prepared by the same method differed only slightly in the number of identified compounds. In general, fish prepared by the delay method had a larger number of compounds compared to fish prepared by the regular method. Further, a greater number and higher levels of compounds were found in the fish obtained from one of the two locations. Overall, the delay preparation method resulted in a greater number of compounds with stronger intensity compared to the regular method.

• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.17-29
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• 2004

A multiresidual analysis was performed to determine 12 sulfonamides(sulfacetamide, sulfadiazine, sulfisomidine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfisoxazole, sulfamethoxazole, sulfaquinoxaline, and sulfadimethoxine) in beef and pork simultaneously. The multiresidual analysis for the sulfonamides currently used was able to analyze 5 kinds of sulfonamides at the same time. The method of this 12 sulfonamides multiresidual analysis in this study was matrix solid-phase dispersion(MSPD) by high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS). The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM: Ethylacetate(3:1), DCM:EA(9:1). Also, samples (84 beef and 205 pork samples) which were positive by EEC-4 plate test from 2001 to 2003 were tested to investigate the kinds of sulfonamides using HPLC. The results from the study were as follows; 1. The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM:Ethylacetate(3:1), DCM:EA(9:1). The method of extraction solvent with DCM:ethyl acetate(9:1) was the most excellent(87.7∼99.3%) in separation and reappearance. 2. In the LC/MS analysis. of sulfonamides, signal to noise ratio was showed relatively high in the positive mode and special ion in the quality analysis was determined via [M+H]$\^$+/ and m/z 156. A spectrum of sulfonamides was showed from all 12 sulfonamides. 3. The samples positive by the EEC-4 plate, a screening test method, were categorized by sulfonamides through Charm II and confirmed the kinds of sulfonamides through HPLC. 1) Among 84 beef samples positive by EEC-4 plate, 20 samples were positive by Charm II and identified as 7 sulfamethazine, 9 sulfadimethoxine, 1 sulfamonomethoxine and 3 unknown status. 2) Among 205 pork samples positive by EEC-4 plate, 42 samples were positive by Charm II and identified as 19 sulfamethazine, 1 sulfadimethoxine, 4 sulfamonomethoxine and 5 unknown status.