• Analytical Science and Technology
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• 제13권5호
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• pp.608-615
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• 2000

A determination method of trace nickel and cobalt in water samples was studied and developed by adsorbing their complexes on ion exchange resin suspension. The analytical ions were formed as complexes with a ligand of APDC (ammonium pyrrolidinedithiocarbamate) and adsorbed on anion exchange resin of Dowex 2-X8. After the suspension was filtered out with membrane filter, the complexes were dissolved in HCl solution by an ultrasonic vibrator for ET-AAS determination. Several conditions were optimized as followings. pH of sample solution: 5.0, amount of ligand APDC: more than 430 times in mole ratio, the type and concentration of acid: 0.1 M HCl, and vibration time: 7 minutes. The addition of palladium in the HCl solution could improve the reproducibility and sensitivity by a matrix modification in the absorbance measurement. This procedure was applied for the analysis of three kinds of real water samples. The detection limits equivalent to 3 times standard deviation of blank were Co 0.36 ng/mL and Ni 0.27 ng/mL and recoveries in spiked samples were 99-102% for cobalt and 100-105% for nickel.

• Korean Journal of Plant Resources
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• 제24권1호
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• pp.1-9
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• 2011

In the present study, the anti-oxidative properties of 80% ethanol extracts from 140 kinds of natural plants were investigated. Persicaria perfoliata had the highest anti-oxidative relative potency(VitaminE, $ORAC_{PE}$=1.0), followed by Sorbaria sorbifolia var. stellipila, Rosa multiflora, Lysimachia vulgaris var. davurica, Quercus aliena, Quercus mongolica and Lespedeza bicolor ($ORAC_{PE}$ ${\geq}$ 1.50). Among them, the anti-oxidative activity values of the n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH, and water fractions of the 80% EtOH extracts of P. perfoliata and S. sorbifolia in the ORAC assay system were $1.13{\pm}0.002$, $1.10{\pm}0.004$, $3.67{\pm}0.232$, $1.62{\pm}0.049$ and $1.05{\pm}0.003$; $1.02{\pm}0.007$, $1.00{\pm}0.016$, $2.94{\pm}0.130$, $1.80{\pm}0.019$ and $1.04{\pm}0.012$, respectively, with marked anti-oxidative activity in the ethyl acetate fraction from selected the 2 plant extracts.

• Journal of the Korean Chemical Society
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• 제8권3호
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• pp.113-120
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• 1964

The critical examination of the spectrophotometric method for determining microgram quantities of phosphate by the n-butyl acetate extraction as molybdophosphoric acid and subsequent development of the molybdenum blue has been made. In this procedure from 2 to 8 ${\mu}g$. of phosphate-phosphorus can be determined under optimum conditions. The final concentration of ammonium molybdate and the final acidity of perchloric acid for the formation of heteropoly acid are suitable to be ranges of 0.5 to 1.1% and 0. 5 to 1. 1 N respectively, and subsequently extracted with 10 ml. of n-butyl acetate. The extract is developed to molybdenum blue with 5.0 ml. of 1. 3% stannous chloride in 1N hydrochloric acid. The color is stable for at least one hour in the use of perchloric acid for the condensation. In order to determination of submicrogram amounts of phosphate, the sensitivity of the molybdenum blue method is hardly sufficient, a sensitive and stable molybdenum(V)-thiocyanate complex method has been investigated. By the procedure less than 1.2 ${\mu}g$. of phosphate-phosphorus can be determined with an accuracy of less than 5% the relative error. The molybdenum(Ⅵ) extracted by the above procedure is reduced to molybdenum(V) in the extract directly with a solution of 4 to 10% of stannous chloride, 0.5 to 1.5 mM of copper, and 0.1 to 0.9 N of perchloric acid as final concentration in 4.3 to 6.3 N of hydrochloric acid or 9.0 to 13.0 N of sulfuric acid by heating for one minute in boiling water, after cooling, the molybdenum(V)-thiocyanate complex color is developed by adding 6.0 M ammonium thiocyanate solution making the final concentration to be in a range of 0.4 to 0.9 M. This procedure the very sensitive, reliable, and stable can be applied to determining submicrogram amounts of phosphate in natural waters with a precision of 1.6 ${\times}\;10^{-2}$ the standard deviation as absorbance.

• Journal of the Korean Society of Food Science and Nutrition
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• 제43권12호
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• pp.1808-1816
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• 2014

The aim of this study was to evaluate the antioxidant activities and anti-inflammatory effects of water and ethanolic extracts from Allium hookeri roots and leaves. Antioxidant activities of Allium hookeri extracts were determined based on various radical scavenging activities using an ESR spectrophotometer, ferric reducing antioxidant power, 2,2'-azinobis-(3-ethybenzothiazoline-6-sulfonic acid) radical scavenging activity, and oxygen radical absorbance capacity assays. In addition, we investigated anti-inflammatory effects of Allium hookeri extract on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. We also explored the effects of extract from Allium hookeri root on suppression of pro-inflammatory mediators such as nitric oxide (NO) and pro-inflammatory cytokines such as IL-6 and TNF-${\alpha}$ against LPS-induced activation of RAW264.7 cells. Our results demonstrated superior antioxidant activity for leaf extract of Allium hookeri compared to extract from root of Allium hookeri. On the other hand, root extract of Allium hookeri showed better anti-inflammatory activity compared to leaf extract. Our study suggests that Allium hookeri extract exhibits strong antioxidant activity and anti-inflammatory effects and can be developed as a potential therapeutic candidate for diseases involving oxidative stress and inflammation.

• Food Engineering Progress
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• 제13권2호
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• pp.138-146
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• 2009

The crude polysaccharide fraction from fruit body of Auricularia auricula were obtained by using hot water extraction and ethanol precipitation. As the crude polysaccharide fraction contained the brownish dark colored compounds, the adsorption study of pigments from the crude polysaccharide using activated carbon was carried out. The pigment compounds showed an absorption characteristic with $\lambda_{max}$ of 230 nm and the absorbance at 230 nm was taken as color intensity. Adsorption capacity of pigment depended on increase of the activated carbon to sample loading ratio. The adsorption capacity increased with increase of pH and temperature in the pH range of 3.0-7.0 and temperature range of 25-40$^{\circ}C$, but decreased in the temperature range of 40-70$^{\circ}C$. The optimum capacity was obtained at addition of 16.7 mg activated carbon per mL sample solution (concentration = 3 mg/mL) at pH of 7.0 and temperature of 40$^{\circ}C$. Treatment for 10 min was sufficient to achieve the 80% decolorization and 1.25 fold purification of polysaccharide. Langmuir isotherm and pseudo second-order kinetic model provided the best fitting for adsorption of the brownish dark colored compounds onto powdered active carbon. The activation energies of adsorption from the Langmuir isotherm parameter in the ranges of 25-40$^{\circ}C$ and 40-70$^{\circ}C$ was -2.54 and 4.38 kcal/g, respectively. The results of low activation energy also indicated that the adsorption process was a physical adsorption which was controlled by diffnsion.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.699-720
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• 1995

This study was conducted to evaluate the effect of benzalkonium chloride solution as a wetting agent instead of water on dentin bonding with NTG-GMA/BPDM system (All-bond 2, Bisco.) and DSDM system (Aelitebond, Bisco.). Benzalkonium chloride solution is a chemical disinfectant widely used in medical and dental clinics for preoperative preparation of skin and mucosa due to its strong effect of cationic surface active detergent. Eighty freshly extracted bovine lower incisor were grinded labially to expose flat dentin surface, and then were acid-etched with 10 % phosphoric acid for 15 second, water-rinsed, and dried for 10 second with air syringe. The specimens were randomly divided into 8 groups of 10 teeth. The specimens of control group were remoistured with water and the specimens of experimental groups were remoistured with 0.1 %, 0.5 %, and 1.0 % benzalkonium chloride solution respectively. And then, the Aelitefil composite resin was bonded to the pretreated surface of the specimens by use of All-bond 2 dentin bonding system or Aelitebond dentin bonding system in equal number of the specimens. The bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, then the tensile bond strength was measured, the mode of failure was observed, the fractured dentin surface were examined under scanning electron microscopy, and FT-IR spectroscopy was taken for the purpose of investigating the changes of the dentin surface pretreated with benzal konium chloride solution followed by each primer of the dentin bonding systems. The results were as follows : In the group of bonding with NTG-GMA/BPDM dentin bonding agent(All-bond 2), higher tensile bond strength was only seen in the experimental group remoistured with 0.1 % benzal konium chloride solution than that in water-remoistured control group(p<0.05). In the group of bonding with DSDM dentin bonding agent (Aelitebond), no significant differences were seen between the control and each one of the experimental group(p<0.05). Higher tensile bond strength were seen in NTG-GMAIBPDM dentin bonding agent group than in DSDM dentin bonding agent group regardless of remoistur ization with benzal konium chloride solution. On the examination of failure mode, cohesive and mixed failure were predominantly seen in the group of bonding with NTG-GMAIBPDM dentin bonding agent, while adhesive failure was predominantly seen in the group of bonding with DSDM dentin bonding agent. On SEM examination of fractured surfaces, no differences of findings of primed dentin surface between the groups with and without remoisturization with benzal konium chloride solution. FT-IR spectroscopy taken from the control and the experimental group reve::.led that some higher absorbance derived from the primers binding to dentin surface was seen at the group pretreated with 0.1 % benzal konium chloride solution than at the control group of remoisturizing with water.

• Journal of Sericultural and Entomological Science
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• 제16권1호
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• pp.21-48
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• 1974

The studies were carried out to disclose the physical and chemical properties of sericin fraction obtained from silk cocoon shells and its characteristics of swelling and solubility. The following results were obtained. 1. The physical and chemical properties of sericin fraction. 1) In contrast to the easy water soluble sericin, the hard soluble sericin contains fewer amino acids include of polar side radical while the hard soluble amino acid sach as alanine and leucine were detected. 2) The easy soluble amino acids were found mainly on the outer part of the fibroin, but the hard soluble amino acids were located in the near parts to the fibroin. 3) The swelling and solubility of the sericin could be hardly assayed by the analysis of the amino acid composition, and could be considered to tee closely related to the compound of the sericin crystal and secondary structure. 4) The X-ray patterns of the cocoon filament were ring shape, but they disappeared by the degumming treatment. 5) The sericin of tussah silkworm (A. pernyi), showed stronger circular patterns in the meridian than the regular silkworm (Bombyx mori). 6) There was no pattern difference between Fraction A and B. 7) X-ray diffraction patterns of the Sericin 1, ll and 111 were similar except interference of 8.85A (side chain spacing). 8) The amino acids above 150 in molecular weight such as Cys. Tyr. Phe. His. and Arg. were not found quantitatively by the 60 minutes-hydrolysis (6N-HCI). 9) The X-ray Pattern of 4.6A had a tendency to disappear with hot-water, ether, and alcohol treatment. 10) The partial hydrolysis of sericin showed a cirucular interference (2A) on the meridian. 11) The sericin pellet after hydrolysis was considered to be peptides composed with specific amino acids. 12) The decomposing temperature of Sericin 111 was higher than that of Sericin I and II. 13) Thermogram of the inner portioned sericin of the cocoon shell had double endothermic peaks at 165$^{\circ}C$, and 245$^{\circ}C$, and its decomposing temperature was higher than that of other portioned sericin. 14) The infrared spectroscopic properties among sericin I, II, III and sericin extracted from each layer portion of the cocoon shell were similar. II. The characteristics of seriein swelling and solubility related with silk processing. 1) Fifteen minutes was required to dehydrate the free moisture of cocoon shells with centrifugal force controlled at 13${\times}$10$^4$ dyne/g at 3,000 R.P.M. B) It took 30 minutes for the sericin to show positive reaction with the Folin-Ciocaltue reagent at room temperature. 3) The measurable wave length of the visible radiation was 500-750m${\mu}$, and the highest absorbance was observed at the wave length of 650m${\mu}$. 4) The colorimetric analysis should be conducted at 650mu for low concentration (10$\mu\textrm{g}$/$m\ell$), and at 500m${\mu}$ for the higher concentration to obtain an exact analysis. 5) The absorbing curves of sericin and egg albumin at different wave lengths were similar, but the absorbance of the former was slightly higher than that of the latter. 6) The quantity of the sericin measured by the colorimetric analysis, turned out to be less than by the Kjeldahl method. 7) Both temperature and duration in the cocoon cooking process has much effect on the swelling and solubility of the cocoon shells, but the temperature was more influential than the duration of the treatment. 8) The factorial relation between the temperature and the duration of treatment of the cocoon cooking to check for siricin swelling and solubility showed that the treatment duration should be gradually increased to reach optimum swelling and solubility of sericin with low temperature(70$^{\circ}C$) . High temperature, however, showed more sharp increase. 9) The more increased temperature in the drying of fresh cocoons, the less the sericin swelling and solubility were obtained. 10) In a specific cooking duration, the heavier the cocoon shell is, the less the swelling and solubility were obtained. 11) It was considered that there are differences in swelling or solubility between the filaments of each cocoon layer. 12) Sericin swelling or solubility in the cocoon filament was decreased by the wax extraction.. 13) The ionic surface active agent accelerated the swelling and solubility of the sericin at the range of pH 6-7. 14) In the same conditions as above, the cation agent was absorbed into the sericin. 15) In case of the increase of Ca ang Mg in the reeling water, its pH value drifted toward the acidity. 16) A buffering action was observed between the sericin and the water hardness constituents in the reeling water. 17) The effect of calcium on the swelling and solubility of the sericin was more moderate than that of magnecium. 18) The solute of the water hardness constituents increased the electric conductivity in the reeling water.

• Journal of Life Science
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• 제25권7호
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• pp.740-747
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• 2015

This study was carried out to evaluate changes in the meat quality and antioxidation activity in the loin and ham of Korean Native Black Pigs (KNBP) during frozen storage at −18℃ for 150 days. The pH value of the loin was decreased as storage days progressed, while the pH value of the ham showed no consistent changes with storage days. The lightness (L*) of the loin did not show any significant reduction until day 120, whereas L* of the ham was significantly declined throughout the storage period (p<0.05). The redness (a*) values of the loin and ham were significantly decreased as storage progressed. The water holding capacity of the loin was decreased by day 30 and that value was maintained until the end of storage. The initial total numbers of microorganisms in the loin and ham were 4.88 and 5.16 Log CFU/g, respectively and these numbers were significantly decreased by day 30 (p<0.05). The levels of 2-thiobarbituric acid reactive substances (a measurement of lipid oxidation) in the loin and ham ranged from 0.057-0.069 and 0.052-0.087 mg MDA/kg meat, respectively, until storage day 150. Volatile basic nitrogen values of the loin and ham ranged from 15.13-16.55 and 16.05-16.23 mg%. Oxygen radical absorbance capacities and carnosine contents of the loin and ham were significantly decreased during frozen storage for 3 months (p<0.05). In summary, the meat quality of the loin and ham from KNBP was somewhat decreased during frozen storage. However, the levels of antioxidants and dipeptides with antioxidant activity were significantly decreased in pork loin and ham during frozen storage.

• Journal of Korean Society of Environmental Engineers
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• 제36권8호
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• pp.534-541
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• 2014

This study investigated a method to determine an efficient operating condition for the $UV/H_2O_2$ process. The OH radical scavenging factor is the most important factor to predict the removal efficiency of the target compound and determine the operating condition of the $UV/H_2O_2$ process. To rapidly and simply measure the scavenging factor, Rhodamine B (RhB) was selected as a probe compound. Its reliability was verified by comparing it with a typical probe compound (para-chlorobenzoic acid, pCBA); the difference between RhB and pCBA was only 1.1%. In a prediction test for the removal of Ibuprofen, the RhB method also shows a high reliability with an error rate of about 5% between the experimental result and the model prediction using the measured scavenging factor. In the monitoring result, the scavenging factor in the influent water of the $UV/H_2O_2$ pilot plant was changed up to 200% for about 8 months, suggesting that the required UV dose could be increased about 1.7 times to achieve 90% caffeine removal. These results show the importance of the scavenging factor measurement in the $UV/H_2O_2$ process, and the operating condition could simply be determined from the scavenging factor, absorbance, and information pertaining to the target compound.

• Applied Biological Chemistry
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• 제36권5호
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• pp.364-369
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• 1993

Triton X-100 enhances to a marked extent the analytical sensitivity of the nitrobluetetrazolium (NBT) reduction method for the assay of superoxide$(O^-_{\.{^.2}})$ production. In the present work, it was attempted to elucidate the physicochemical nature of this Triton X-100 effect, focusing on not only the surfactant-caused stabilization of the water-insoluble formazan colloid but also the kinetic competition between the $NBT-O^-_{\.{^.2}}$ reaction and the autodisproportionation of concommitantly occuring in aqueous media. The measurements of formazan and $H_2O_2$ formed in a number of reaction systems, as prepared by vortex-mixing potassium superoxide dissolved in an aprotic solvent with aqueous solutions of NBT, revealed that Triton X-100 exerts its effect both through preventing formazan colloid from aggregation and thereby increasing the formazan absorbance and through suppressing the autodisproportionation reaction of $O^-_{\.{^.2}}$. It also turned out that the relative shares of the colloid stabilization effect and the kinetic effect in the contribution to the sensitivity amplification of the NBT method are dependent upon the reaction conditions, particulary the molar concentration ratio of NBT to $O^-_{\.{^.2}}$ in the reaction systems.