• 제목/요약/키워드: A new reagent

검색결과 148건 처리시간 0.033초

1-isonicotinyl-2-furfurylidene hydrazine-Cd(II) 착화합물에 관한 분석화학적연구 (Spectrophotometric study of the cadmium (II) complex of 1-isonicotinyl-2-furfurylidene hydrazine)

  • 백남호;박만기
    • 약학회지
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    • 제13권1호
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    • pp.33-37
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    • 1969
  • A new organic reagent, 1-isonicotynyl-2-furfurylidene hydrazine synthesized from isonicotinic acid hydrazid and furfural, gives yellow liquid with cadmium (II). Cadmium complex of the reagent is soluble in water with yellow coloration. The complex has a maximum absorption at 363 m${\mu}$ and molar ratio of cadmium to reagent was estimated as 1:1 by continuous variation method and slope method. Molecular extinction coefficient and apparent formation constant of this complex was spectrophotometrically determined. K=4.48 $\times$ 10$^{3}$ (Babko's method) K=1.33 $\times$ 10$^{3}$ (Anderson's method)

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Synthesis, Characterization and Structure of DBU-hydrobromide-perbromide: A Novel Oxidizing Agent for Selective Oxidation of Alcohols to Carbonyl Compounds

  • Bakavoli, Mehdi;Rahimizadeh, Mohammad;Eshghi, Hossein;Shiri, Ali;Ebrahimpour, Zahra;Takjoo, Reza
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.949-952
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    • 2010
  • A new and efficient reagent for the conversion of primary and secondary alcohols into their corresponding aldehydes and ketones is introduced. The reagent was easily prepared from the reaction of DBU with molecular bromine in $CHCl_3$. The structure of the reagent as $DBUH^+{Br_3}^-$ was determined by single crystal X-ray diffraction analysis.

Alternative Immunossays

  • Barnard, G.J.R.;Kim, J.B.;Collins, W.P.
    • 한국가축번식학회지
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    • 제9권2호
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    • pp.133-139
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    • 1985
  • An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

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DETERMINATION OF TRIETHANOLAMINE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH POST COLUMN REACTION

  • Kim, Jin-Woo;Kim, Seung-Jung;Lee, Bo-Seaub
    • 대한화장품학회지
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    • 제14권1호
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    • pp.1-15
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    • 1988
  • A new method for liquid chromatography with post column reaction is suggested for the separation and quantification of tertiary amines. A mixture of triethanolamine and N-ethyl diethanolamine was separated by a strong cation exchange column, followed by spectrophtometric detection of the blue colors generated from the reaction of each amine with the Folin-Ciocalteau reagent. The tertiary amines were properly separated when an eluent of pH 9.5 containing 0.5M sodium nitrate was used. Under this condition, calibration curve of triethanolamine in 2-10mg/100ml concentration range was attained. Good results were obtained when cream and shampoo preparations containing known amount of triethanolamine were analysed according to this method. In case the sample did not contain any other interfering reducing substances, the amine was quantitatively determined by the simple reaction of the samples with Folin-Ciocalteau reagent, and the subsequent spectrophotometric measurement.

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p-Nitropheneyl Diazonium Fluoborate를 이용한 후추 Piperine의 새로운 비색정량법 (A New Method of Colorimetric Determination of Piperine Using p-Nitrophenyl Diazonium Fluoborate in Pepper (Piper Nigrum L.))

  • 리성갑
    • 한국식품과학회지
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    • 제6권2호
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    • pp.56-60
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    • 1974
  • 후추의 매운맛을 주는 자극성분인 piperine 정량에 대한 가능한 방법들에 관하여 조사정리 하였고 또 새로운 정량법으로 후추의 매운 성분을 $140^{\circ}C$에서 알카리 가수분해로서 유리된 piperidine을 p-nitrophenyl diazonium fluoborate reagent와 반응처리 시킴으로서 530nm에서 최고 흡광도를 보여주고 안정된 적색 복합화학물을 생성시켜 이 복합물의 색을 colorimeter로 측정하는 비색정량법을 개발하였다. 이 새로운 방법은 후추의 전 매운맛의 주성분인 piperine의 정량에 특히 유용하였다. 이 분석법의 장점은 일반 적정법보다 적은 양의 시료로서 후추에 함유된 자극성분인 piperine의 측정이 가능한 것이다.

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