• Journal of Pharmaceutical Investigation
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• v.15 no.3
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• pp.151-159
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• 1985

For the determination of aliphatic carbamates, the quantitative analysis of carisoprodol was investigated by gab chromatography (GC) and spectrophotometry. All the methods studied were found to be very quantitative. The minimum experimental amounts of GC method, spectrophotometric method I and II were approximately $10^{-9},\;10^{-5}$ and $10^{-8}$ mole, respectively. The obtained results showed that GC method I was much more sensitive and rapid than spectrophotometric method II.

• Journal of the Korean Chemical Society
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• v.12 no.2
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• pp.51-54
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• 1968

Rapid flame spectrophotometric method is developed to determine a small amount of sodium in zircon frit and high purity zirconium compounds. The instrumental characteristics and the optimum conditions are studied and a comparison between calibration curve method and standard addition method is made.

• Journal of the Korean Chemical Society
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• v.68 no.1
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• pp.20-24
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• 2024

This article presents the advantages of utilizing gossypol and its derivatives as reagents for iron (III) (Fe (III)) ions. A novel spectrophotometric method has been developed for the determination of Fe (III) using gossypol derivatives in the presence of a universal buffer solution. Optimal conditions have been identified, and the composition and stability constants of the Fe (III) complex with gossypolacetic acid have been determined.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.268-273
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• 1999

To measure the precision of Soiltek$^{(R)}$ KA-1 spectrophotometric measurement of soil available phosphate, standard deviation, C;V, and relative sensitivity were investigated, comparing to Lancaster method. Available phosphate concentration measured by Soiltek$^{(R)}$ KA-1 spectrophotometric method was highly correlated with Lancaster method($r=0.998^{***}$) and the slop of regression equation was close to 1.0. There were no differences in standard deviation. CV, and relative sensitivity for soil available phosphate concentrations measured by two methods. Regarding to convenience of experimental procedure and instrumental operation, and time saving analysis, Soiltek$^{(R)}$ KA-1 spectrophotometric measurement for soil available phosphate is highly recommended.

• Restorative Dentistry and Endodontics
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• v.47 no.1
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• pp.8.1-8.9
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• 2022

Objectives: The aim of this study was to compare the color change of the Giomer resin composite (Beautifil-Bulk) by using photographs obtained with a smartphone (iPhone 6S) associated with Adobe Photoshop software (digital method), with the spectrophotometric method (Vita Easyshade) after immersion in different pigment solutions. Materials and Methods: Twenty resin composite samples with a diameter of 15.0 mm and thickness of 1.0 mm were confectioned in A2 color (n = 5). Photographs and initial color readings were performed with a smartphone and spectrophotometer, respectively. Then, samples were randomly divided and subjected to cycles of immersion in distilled water (control), açai, Coke, and tomato sauce, 3 times a day, 20 minutes for 7 days. Later, new photographs and color readings were taken. Results: The analysis (2-way analysis of variance, Holm-Sidak, p < 0.05) demonstrated no statistical difference (p < 0.005) between the methods in all groups. Similar color changes were observed for all pigment solutions when using the spectrophotometric method. For the digital method, all color changes were clinically unacceptable, with distilled water and tomato sauce similar to each other and with statistical differences (p < 0.005) for Coke and açai. Conclusions: Only the tomato sauce produced a color change above the acceptability threshold using both methods of color assessment. The spectrophotometric and digital methods produce different patterns of color change. According to our results, the spectrophotometric method is more recommended in color change assessment.

• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.182-186
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• 2002

The Coptidis rhizoma is known for containing protoberberine alkaloids. Berberine, coptisine and palmatine are the major constituents of protoberberine alkaloids. The alkaloids were isolated and determined by forming complex compounds from Coptidis rhizoma in preparation I(Sam-Hwang-Sa-Sim-Tang) and II(Hwang-Ryen-Tang). For the determination of these alkaloids, a new spectrophotometric method was developed with a simple and selective sample clean-up using thiocyanatocobaltate[II] complex compound ion. The absorbance of alkaloidal complex compounds in l.2-dichloroethane solution was measured at 625 nm. Calibration curve for the alkaloids isolated from Coptidis rhizoma was linear over the concentration range of 0.2-0.3 mg/ml. The method was proved to be rapid, simple and reliable for the isolation and the determination of the alkaloids in Coptidis rhizoma preparation I and II.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.1
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• pp.84-101
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• 1996

To minimize the use of animals in toxicity testing, and to reduce the cost in vivo test, more rational test method was described which determines, in the same animal, photoxic and photoallergic potential of a substance, and is daptable to routine testing. The other purpose of this study was to investigate the usefulness of in vivo alternatives ; photostability and spectrophotometric carbonyl assay. In this modified photosensitization model, animal numbers and resting periods, the number and method of topical application were simplified. Two positive photoreactive agents, Benzocaine and 6-methyl coumarine, showed a similar photoallergic potential to that of Ichikawa's method. Two sunscreens, Octyl methoxy cinnamate, Butyl methoxyl dibenzoyl methane, hardly showed photoallergic potentials. The photostability test could be used in the step of prescreening of photosensitization potential because most of the photoreactive agents represented the reduction of more than 20% in the absorbance. And photoreactive agents have a high potential of photosensitization in the sddessment of spectrophotometric carbonyl level although two sunscreens have a low possibility of photosensitization. Therefore this method was assumed as a valuable in vivo alternatives in the respect even in the very low concentrations which phototoxicity test using almonella showed no phototoxic potential.

• Journal of Periodontal and Implant Science
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• v.53 no.4
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• pp.295-305
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• 2023

Purpose: Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°). Methods: Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes. Results: Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement. Conclusions: T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.421-425
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• 2001

Among the many parameters describing water quality, total nitrogen content(TN) is regarded as important one in relation to water quality management of the waterbodies for its role in eutrophication process. This study evaluated for accuracy, convenience and promptness of nitrogen analysis methods : (1)UV spectrophotometric method, (2)summation method, (3)cadmium reduction method. And, the detection limit of each method was calculated using EPA method. The UV spectrophotometric method after oxidation appears to be more convenient and accurate in determination of the TN contents than the summation method and cadmium reduction method. The summation method is necessary to separate determinations of the organic nitrogen, ammonia, nitrite, and nitrate. And, because summation method has many other methods for each contents, it can be detected for wide range of concentration.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.81-96
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• 2020

Berthlot's reaction spectrophotometric method is generally used for the analysis of dissolved ammonium in seawater, but in recent years, a fluorescence method using an orthophthaldialdehyde-sulfite (OPA) fluorescent reagent is actively used internationally. In this study, we investigated the effects of the detection limit between the analysis methods, the reagent refractive index inherent in the spectrophotometric method, and the use of different calibration curves to understand the cause of the difference in dissolved ammonium concentration (about 0.31 𝜇M) observed in the seawater samples and a nutrient reference material between two institutions (KIOST (spectrophotometric method, one-order linear regression gradient only), Australia CSIRO (fluorescence method, quadratic formula)) conducted onboard the Australian R/V Investigator in 2017. The method detection limit (0.063 𝜇M) and the reagent refractive index background value (0.054 𝜇M) of the spectrophotometric method measured in this study could explain the difference in dissolved ammonium concentration values of the two institutes about 20% and 17%, respectively. However, when the concentration of the calibration curve of the spectrophotometric method was calculated using the same quadratic as the fluorescence method or the slope and intercept of linear regression, the difference in the dissolved ammonium concentration between the two institutions was reduced to less than the detection limit of the spectrophotometric method. Therefore, the difference in the concentration of dissolved ammonium between the two institutions, found in the nutrient reference materials and the seawater field sample during the international onboard nutrient inter-comparison experiment, may be attributed to be the effect of the different calibration curves used in the two methods rather than the effect of the difference in two analytical methods. When comparing the dissolved ammonium data from seawater samples in the future, it is recommended to pay attention to the information on the baseline, number of standard solutions, and calibration curve used in the analysis.