• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.71-76
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• 2018

Norovirus is a leading cause of sporadic pathogenic non-bacterial gastroenteritis worldwide. For the detection of norovirus, reverse transcription real-time PCR (RT qPCR) has quickly become a major tool due to its sensitivity and specificity. However, accurate viral RNA extraction methods are essential for RT qPCR analysis. TRIzol reagents are used to extract RNA from biological materials and are therefore widely used for norovirus RNA extraction. In this study, the yield of viral RNA extraction using TRIzol from genogroup II (GII) among the human norovirus genogroup I (GI) and GII, and murine norovirus (GV) depended on the pH of the virus sample solution. The yield of RNA extraction was higher at the alkaline pH than in the acidic region compared with the Ct (threshold cycle) value of the real-time PCR. From the results of this study, it was found that the pH condition is very important for the quantitative analysis of norovirus by extracting GII RNA using TRIzol.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.376-379
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• 2004

pH has been regarded as a master variable governing the heavy metal sorption on fly ash. However, the chemical constituents in the fly ash could also suggest a potential sorption site for heavy metals. So, in this study sequential extraction method is employed to evaluate the sorption behavior of fly ash for cadmium. Two different fly ashes (S-fly ash, T-fly ash) were obtained from different power plants in Korea. First, cadmium is adsorbed under four different initial pHs. And, Cd sorbed in fly ash was sequentially desorbed following the sequential extraction method suggested by Tessier. In test results, the effect of pH increase was differently exerted in two fly ash. In S-fly ash, exchangeable fraction was dominated in low initial pH, however, as increasing initial pH, the fraction bound to carbonate increased. In the T-fly ash, regardless of initial pH the fraction bound to carbonate was major part of sorption estimated. The fraction bound to Fe/Mn oxide was about 10% in T-fly ash, and 5% in S-fly ash at high pH.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.65-70
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• 1985

To recover proteins from antarctic krill(Euphausia superba) for the use of food material, some factors affecting the extraction of protein were investigated. The protein solubility profile showed a minimum solubility level(33.2-38.8%) within the range of pH4.0-4.5 and very high solubility levels as 56.8% at pH2.0 and 80.7% at pH11.0. The extraction yield increased as the solvent-to-krill ratios increase in which a ratio of 5:1(volume of solvent/weight of krill) was found to be preferable from the point of handling convenience and extraction yield. The extraction temperatures did not seem to be important variables on extraction of protein. The extraction of krill protein occurred fairly rapidly with little further extraction of protein after 30 minutes. The extraction of protein was slightly decreased at both acidic(pH2.0) and alkaline(pH11.0) conditions with the increasing concentration of sodium chloride. The extractibility of krill protein at strong alkaline condition(pH11.0) was higher than at strong acidic condition(pH2.0) under the same concentration range as 1-6% of sodium chloride. In phosphate treatments, the extraction of protein was slightly influenced by presence of sodium chloride as the concentration range of 3-4% in the aqueous solvent by which maximize the extraction yield as over 80%.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.241-245
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• 1997

In order to make natural food color from Gardenia, we investigated optimal conditions of color extraction, and thermal stability and light stability of color extracted compared with Yellow-4. In case of ethanol extraction, optimal conditions for color extraction were substrate 10%, 4$0^{\circ}C$, pH 7.0 and 42rs, respectively. In case of water extraction, optimal conditions for color extraction were substrate 10%, 7$0^{\circ}C$, pH 7.0 and 48hrs, respectively. Extraction yield in the optimal conditions was 75% in ethanol and 63% in water. The thermal stability and light stability of Yellow-4 were both upper 98%, but those of Gardenia yellow color were 62 and 90%, respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.100-109
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• 1999

This study evaluates the pretreatment for analysis of benzidine metabolites in urine by measuring the recovery rates according to the temperature and periods of storage of the urine. By the solid phas e extraction, the recovery rates of basic hydrolysis are benzidine 67.4 %, monoacetylbenzidine 105.1 %, and diacetylbenzidine 115.8 %, respectively. By the liquid extraction, the recovery rates of back-extraction into 0.1 M perchloric acid are benzidine 105.7%, monoacetylbenzidine 94.2 %, diacetylbenzidine 72.8 %, respectively. The difference of the recovery rates between the back-extraction into 0.1 M HCl and 0.1 M perchloic acid after basic hydrolysis are 101 % and 98.8 %, respectively. When the recovery rates of the urinary s amples of pH 3, pH 7, pH 12 at $25^{\circ}C$ and $-76^{\circ}C$ are compared for four weeks, there are no differences according to the temperature and the periods of storage. The above results show that the solid phase extraction and back-extraction by 0.1 M perchloric acid after basic hydrolys is are suitable for the analysis of benzidine metabolites. There are no difference of the recovery rates of the urinary samples stored at $25^{\circ}C$ and $-76^{\circ}C$ at pH 3, pH 7, pH 12, respectively for 28 days.

• Resources Recycling
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• v.13 no.4
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• pp.39-45
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• 2004

Solvent extraction experiments of Nd from chloride solution were studied with PC88A. Solvent extraction reaction of Nd with PC88A and the equilibrium constant were evaluated from the extraction experimental data and extraction conditions. Nd$aq^{3+}$ + 1.5 $H_2$$A_2$,org = $NdA_3$,org + 3H/sun $aq^{+}$ , K=0.25 The predicted distribution coefficients of Nd agreed well with the experimental results. The effect of saponification of PC88A on the extraction of Nd and on the change of equilibrium pH was investigated. Saponified PC88A present as a monomer in the organic reaction and enhanced the distribution coefficient of Nd. The initial extraction conditions had a great effect on the equilibrium pH.

• Korean Journal of Metals and Materials
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• v.56 no.12
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• pp.870-877
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• 2018

Cyanex 272 shows the highest separation factor for the rare earth elements from hydrochloric acid solution among the organophosporus acidic extractants, D2EHPA and PC 88A. Solvent extraction of Tb(III) from weak hydrochloric acid solution with an initial pH 3 to 6 was compared with Cyanex 272, its mixture with Alamine 336, and ionic liquid with Aliquat 336. The solvent extraction reaction of Tb(III) using Cyanex 272 was the same as that of light rare earth elements. Synergism was observed for the extraction of Tb(III) by the mixture with Alamine 336 when the initial concentration ratio of Cyanex 272 to Alamine 336 was higher than 5. Use of the ionic liquid led to a great increase in the extraction percentage of Tb(III) from the same initial extraction conditions. While the equilibrium pH of the mixture was always lower than the initial pH, under some conditions extraction with the ionic liquid resulted in a higher equilibrium pH than the initial pH. The loading capacity of the mixture and the ionic liquid was the same and 2.6 times larger than that using Cyanex 272 alone. Ionic liquid was recommended as a suitable extractant for the extraction of Tb(III) from hydrochloric acid solution based on the ease of handling and higher extraction percentage.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.205-217
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• 2017

Mineral carbonation by indirect method has been studied by serpentinite as cation source. Through the carbonation of $CO_2$ and alkaline earth ions (calcium and magnesium) from serpentinite, the pure carbonates including $MgCO_3$ and $CaCO_3$ were synthesized. The extraction solvent used to extract magnesium (Mg) was ammonium sulfate ($(NH_4)_2SO_4$), and the investigated experimental factors were the concentration of $(NH_4)_2SO_4$, reaction temperature, and ratio of serpentinite to the extraction solvent. From this study, the Mg extraction efficiency of approximately 80 wt% was obtained under the conditions of 2 M $(NH_4)_2SO_4$, $300^{\circ}C$, and a ratio of 5 g of serpentinite/75 mL of extraction solvent. The Mg extraction efficiency was proportional to the concentration and reaction temperature. $NH_3$ produced from the Mg extraction of serpentinite was used as a pH swing agent for carbonation to increase the pH value. About 1.78 M of $NH_3$ as the form of $NH_4{^+}$ was recovered after Mg extraction from serpentinite. And, the main step in Mg extraction process of serpentinite was estimated by geochemical modeling.

• Journal of Fashion Business
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• v.11 no.2
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• pp.102-112
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• 2007

Effect of the pH condition was examined on extraction and dyeing of the yellow and red dyes of safflower. Absorption of dye solution extracted from safflower was changed by pH of solvent. In the case of yellow dyes, cotton and ramie weren't dyed regardless of pH of dye bath, but silks were significantly dyed at pH4. Raw silk showed better dyeability than refined silk. In the case of red dyes, cotton and ramie absorbed red dyes selectively, but silks absorbed yellow dyes more significantly than red dyes. Efficiency of extraction and dyeing of yellow dyes in acidic range were find out higher than that in neutral range. Red dyes was effectively extracted at pH11 and dyed at pH6.

• KSBB Journal
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• v.14 no.6
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• pp.661-664
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• 1999

Proteins were extracted from an aqueous phase with reversed micelles. The effect of pH, and salt concentration on the solubilization of lysozyme in AOT/isooctane solution was studied to explore the potential for employing this solvent system in the large-scale recovery and concentration of proteins using liquid extraction. For pH values below the isoelectric point, pl of the protein, solubilization was high, probably owing to strong electrostatic interactions between the positively charged proteins and the anionic surfactant heads forming the inner micelle wall. At low ionic strength complete solubilization of the protein was observed. A pH higher than the pl of lysozyme and a salt concentration lower than that of the water pool were required for the recovery aqueous phase to ensure the back extraction of lysozyme from the AOT reversed micelles.