• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.616-621
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• 1990

The spectrophotometric methods for the determination of Nd, Pr, Sm, Eu, Ho, Er were developed, using the multicomponent method of absorption spectra cointerference. The absorption spectra of individual Nd, Pr, Sm, Eu, Ho, Er, mixture of Sm, Eu, Ho, Er in hydrochloric acid solutions were investigated, and also a band register which includes the molar absorptions for all trivalent Nd, Pr, Sm, Eu, Ho and Er absorption band maxima were measured. The spectrophotometric determination of Nd, Pr, Sm, Eu, Ho and Er were investigated using the analytically significant absorption bands at 444.2, 575.1, 401.7, 394.2, 416.6, and 379.7 nm, respectively.

• Analytical Science and Technology
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• v.34 no.5
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• pp.212-224
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• 2021

The intent of the present work was to develop a simple, sensitive, accurate, precise, rapid and economical UV- spectrophotometric and reverse phase high pressure liquid chromatographic method for the simultaneous estimation of Spironolactone and Furosemide in bulk and combined tablet dosage forms. UV-Spectrophotometry was carried out by simultaneous equation method using 0.02 M potassium dihydrogen phosphate buffer pH 3.5: Acetonitrile (50:50) v/v as a solvent. The linearity range was 2-14 ㎍ mL^-1 for Spironolactone and Furosemide with a correlation coefficient > 0.99. The chromatographic separation was achieved on 250 mm × 4.6 mm, hypersil BDS C18 column with particle size 5 ㎛, by using an isocratic mixture of 0.02 M potassium dihydrogen phosphate buffer pH 3.5: Acetonitrile: tert butyl methyl ether (49:50:1) v/v/v as a solvent at a flow rate of 1 mL min^-1 and UV detection was carried out at 254 nm. The retention time were observed to be 3.666 and 6.661 minutes for Furosemide and Spironolactone respectively. The two developed methods were validated according to the ICH guidelines for accuracy, precision, linearity, LOD, LOQ and were found to be within the limits. It can be concluded that these two methods could be successfully used for the simultaneous estimation of Spironolactone and Furosemide in bulk and combined tablet dosage forms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.95-100
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• 2006

Sesamin and sesamolin, antioxidant lipidsoluble lignan compounds, are abundant in sesame (Sesamum indicum L.) seed oil and provide oxidative stability of oil related to sesame quality. The sesamin and sesamolin contents of 403 sesame land races of Korea were determined by HPLC analysis of methanol extract (HPLC value), and their total lignan content was compared with those by using UV-Vis spectrophotometric analysis (UV method) of methanol (UV-MeOH value) and hexane (UV-Hexane value) extracts. HPLC values of total lignan content were strongly associated with UV-Hexane (r=0.705**) and UV-MeOH (r=0.811**) values. The UV values from both the extracts were 3.8-4.7 times higher than those of HPLC values. Lignan content was overestimated by UV method because total compounds in the mixture solution were quantified by absorbing at the same ultraviolet wavelength as in HPLC method. UV method could more rapidly analyze small amount of sample with higher sensitivity of detection than HPLC method. Average contents of lignans in sesame germplasm evaluated in this study were $2.09{\pm}1.02mg/g$ of sesamin, and $1.65{\pm}0.61mg/g$ of sesamolin, respectively, showing significant variation for lignan components. The results showed that UV method for the determination of sesamin and sesamolin could be practically used as a faster and easier method than HPLC by using the regression equations developed in this study.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.1-5
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• 1998

A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.160-165
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• 1989

Binding of sulfaethidole to bovine serum albumin was studied by equilibrium dialysis, fluorescence probe technique, uv difference spectrophotometry and circular dichroism. Equilibrium dialysis method enabled us to estimate the total number of drug binding sites of albumin molecule. For sulfaethidole, albumin had 6 primary and 40 secondary binding sites. The primary and secondary binding constants were 0.9 * 10/sup 5/ M/sup -1/ and 0.2 * 10/sup 6/ M/sup -1/, respectivitely. 1-Anilino-8-naphthalenesulfonate (ANS) and 2-(4-hydroxylbenzeneazo)- benzoic acid (HBAB) were used as the fluorescence probe and the uv spectrophotometric probe, respectively. In fluorescence probe technique, results indicated that the number of higher affinity drug binding site of albumin was 1 and the number of lower affinity drug binding sites of albumin was 3, and the primary and secondary drug binding constants for bovine serum albumin were 2.15 * 10/sup 5/M/sup -1/ and 1.04 * 10/sup 5/ M/sup -1/, respectively. In uv difference spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above results suggest that several different methods should be used in ompensation for insufficient information about drug binding to albumin molecule given by only one method.

• YAKHAK HOEJI
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• v.34 no.1
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• pp.22-33
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• 1990

Aqueous solution of bis(2,4-diaminophenyl)phosphonate(APP) was very stable, especially below pH 2.0 and the red-color compound formed by the reaction of APP and $IO_3-$ was stable at room temperature. A simple and rapid spectrophotometric method for the determination of ascorbic acid, potassium antimonyl tartrate (PAT), and isonicotinic acid hydrazide (INAH) was established by the reaction of $IO_3-$ and these reducing drugs, and the absorbance measurements were made at 500 nm. In the reaction of $IO_3-$ and each of the reducing drugs, the conditions of pH were suitable below 2.5 for ascorbic acid, below 2.0 for PAT, and below 1.5 for INAH. Beer's law did hold in the range of $17.6{\sim}1549.9\;ug$ for ascorbic acid, $33.4{\sim}2871.8{\mu}g$ for PAT,and $6.9{\sim}548.6\;{\mu}g$ for INAH. Many common ingredients present in pharmaceutical dosage forms did not interfere. The average recoveries for ascorbic acid and INAH in pharmaceutical formulations were 99.8 $-100.3\;{\pm}\;0.2{\sim}0.4%$, $99.8\;{\pm}\;0.3%$, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.81-88
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• 1998

The aim of this study is to evaluate several plant extracts with a view to developing UV sunscreen agents. In this study, 150 plant extracts were screened to elucidate their UV spectra using spectrophotometric method. Several plant extracts such as Phellodendron amurense, Morus alba, Rhododendron mucronulatum, Brassica alba have strong absorbency at UVA region (350nm), the suntanning wavelength. And Sophora flavescens, Caesalpinia sapper, Morus alba, Phellodendron amurense, showed absorption plateau value at UVB region (308nm), the erythema action wavelength. These extracts have a good absorbency property as synthetic filter and could be served as substitutes for synthetic UV sunscreen agents.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.137-140
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• 2006

This paper describes a technique combining chemometrics with UV spectroscopy for the determination of the concentra tions of two tissue additives (i.e., wet strength and softening agents) in a cellulose fiber containing solution. In single as ent solutions, the concentration of the additive can be measured by UV spectroscopy at the wavelength where the species having absorption. For a binary (i.e., containing two additives) solution system, the spectral characterization is very complicated. However, if aided by a chemometrical calibration technique, each additive in the binary solution can be quantified simultaneously. The present method is very rapid and simple, it can easily perform a continuous measurement in the changes in the additives' concentration after fiber addition, and therefore this becomes a valuable tool for the adsorption kinetics study of chemical additives onto the cellulose fibers. The time-dependent adsorption behaviors of the wet-strength, softening agent, and their both on fiber were also presented.

• Analytical Science and Technology
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• v.20 no.1
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• pp.25-32
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• 2007

The measurement methods for total nitrogen in wastewater containing a high concentration of nitrogen were evaluated. (1) The UV spectrophotometry, (2) reduction-distillation Kjeldahl, (3) total Kjeldahl nitrogen, and (4) ion chromatography methods were applied. The experimental procedure of the UV spectrophotometric method was simple, but it produced large errors deriving from the dilution of samples and calibration standards. While, the reduction-distillation Kjeldahl method didn't need dilution, but the amount of Devarda's alloy and NaOH lead to large errors up to 50 mg/L. The levels of total nitrogen measured by each method were as follows: reduction-distillation Kjeldahl ($568.6{\pm}38.7mg/L$) > UV spectrophotometry ($527.3{\pm}9.6mg/L$) > total Kjeldahl nitrogen method ($494.7{\pm}21.4mg/L$) > ion chromatography method ($417.9{\pm}7.3mg/L$). Therefore, the reduction-distillation Kjeldahl method is preferred for wastewater with the high concentration of nitrogen. Optimal conditions for each experimental procedure, however, are needed to be confirmed, and the Standard Operation Procedure (SOP) for total nitrogen is required for reliable measurements.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.99-105
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• 1997

In the paper, aging of insulating oil in pole transformer has been studied by performing accelerated thermal aging test. Dissolved gases were extracted by air bubbling method. Concentration of dissolved gases were modified by extraction ratio of each gases in insulating oil. Aging of insulating materials were proceeded by thermal degradation and oxidation reaction. Both of the reactions followed zeroch order kinetics. Formation rate equations for hydrocarbons, carbon oxides, and hydrogen were derived. It was conformed by gas analysis and UV-Visible spectrophotometric method that iron core and copper coil in pole transformer act as catalyst during the aging process.