Acetyl Chloride

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Jinmao You - One of the best experts on this subject based on the ideXlab platform.

  • fluorescence properties of carbazole n 2 methyl Acetyl Chloride and determination of amino compounds via high performance liquid chromatography with pre column fluorescence derivatization
    Journal of Chromatography A, 1999
    Co-Authors: Jinmao You, Wenjian Lao, Xuejun Sun
    Abstract:

    A sensitive LC method for the determination of amino compounds with fluorescence detection has been developed. The reaction of fluorescent tagging reagent, namely carbazole-N-(2-methyl)Acetyl Chloride (CMA-Cl), with amino acids is reported. Emission maximum for the CMA derivatives of amino acids is 360 nm (λex=335 nm). In all cases, the derivatives exhibit strong fluorescence, whereas the reagent itself also exhibits fluorescence. It is found that the labelled derivatives using CMA-Cl are very stable; <4% decomposition occurs after heating at 40°C for 24 h in neutral solution. Fluorescence intensity of amino acid derivatives is higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a gradient elution, offers baseline resolution of 18 amino acids including Orn from a linear acetonitrile gradient (here, Asn, Gln and Trp are not tested, the principal reasons: Gln and Asn, in a real sample hydrolysed, have been changed into Glu and Asp; Trp gives as much as 60% loss of its monosubstituted derivative under proposed derivatization conditions.). Separation of derivatives is carried out on a reversed-phase C18 column with good reproducibility. Derivatization and chromatographic conditions are optimized. The relative standard deviations (n=6) for 50 pmol of each amino acid derivative are <4.5%. The detection limits, calculated by the corresponding peak heights (in cm) by injecting successively lower concentrations until a signal-to-noise of 3:1, are 10–65 fmol for the labelled amino acids.

  • fluorescence properties of carbazole 9 yl Acetyl Chloride and its application for the simultaneous determination of amino acids and biogenic amines via liquid chromatography with fluorescence detection
    Analytica Chimica Acta, 1999
    Co-Authors: Jinmao You, Haitao Sun, Wenjian Lao
    Abstract:

    Abstract A rapid and sensitive derivatization method, using carbazole-9-yl-Acetyl Chloride (CRA-Cl) as derivatization reagent, for the simultaneous determination of amino acids and biogenic amines with pre-column fluorescence derivatization via liquid chromatography is investigated. The wavelength of maximum emission for the CRA derivatives is 365 nm (λex 335 nm). Fluorescence spectra of non-acyl Chloride CRA in the presence of various salts, organic halides and different surfactants are also studied. The quenching constants of NaF, NaCl, NaBr, NaI, and CH3I to CRA are 9.4, 12.6, 40.4, 56.2, and 102 M−1, respectively. Heavy atoms (above 1.0 μM) will seriously interfere with CRA emission spectra tested in the presence of halogen-salts and iodomethane. On the basis of Stern–Volmer equation for static quenching and a solute–micelle interaction linear relationship, the monomer quenching constant K of hexadecyltrimethylammonium bromide (CTMAB) to CRA is 3.0×103 M−1. The binding constants K of micelle of CTMAB and TX-100 to CRA are 5.4×103 M−1 and 2.0×103 M−1, respectively. In addition, in a kinetic analysis of CRA emission intensity (ln Iem) a linear correlation between ln Iem and 1/T was found. The slope of the working curve yields an emission stabilization energy of 17.8 kJ/mol. Derivatization and chromatographic conditions for simultaneous separation of derivatized amino acids and biogenic amines have also been optimized on a reversed-phase C18 column using a binary gradient. Studies on derivatization conditions indicate that primary and secondary amines react very fast with CRA-Cl in alkaline solution to give the corresponding fluorescent derivatives, which exhibit excellent sensitivity and stability. This method, in conjunction with a multi-gradient program, offers a complete resolution for amino acids and biogenic amines. For rapid separation of biogenic amines in plant tissue, an isocratic elution is used. Excellent response linearity is demonstrated over the injected amounts range 50–250 pmol for biogenic amines. The relative standard deviations (n=6) at an analytical concentration of pmol level are

  • high performance liquid chromatographic determination of n nitrosoamines by pre column fluorescence derivatization with acridone n Acetyl Chloride
    Talanta, 1999
    Co-Authors: Jinmao You, Xinjun Fan, Wenjian Lao, Qingcun Zhu
    Abstract:

    A sensitive high performance liquid chromatographic method for the determination of N-nitrosoamines with pre-column fluorescence derivatization has been developed. N-nitrosoamines are first changed into secondary amines using denitrosation reagent, then react with acridone-N-Acetyl Chloride (ARC-Cl) to produce corresponding secondary amine derivatives, which exhibit a strong fluorescence. Maximum emission for ARC derivatives is 430 nm (lambda(ex) 404 nm). The labelled derivatives are very stable, less than 4% decomposition occurs after heating at 40 degrees C for 24 h. Fluorescence intensities of derivatives are higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a multi-gradient program, offers a baseline resolution of the ARC derivatives from a linear acetonitrile gradient. Separation is carried out on a reverse phase C(18) column. Derivatization and chromatographic conditions are optimized. The relative standard deviation (n=6) at an analytical concentration of 10 pmol of each N-nitroamine is less than 4.5%. The detection limits at the fmol level. The method described is also suitable for analysis of other amino compounds in different biological samples.

Arijit Chakraborty - One of the best experts on this subject based on the ideXlab platform.

Abu T Khan - One of the best experts on this subject based on the ideXlab platform.

Wenjian Lao - One of the best experts on this subject based on the ideXlab platform.

  • fluorescence properties of carbazole n 2 methyl Acetyl Chloride and determination of amino compounds via high performance liquid chromatography with pre column fluorescence derivatization
    Journal of Chromatography A, 1999
    Co-Authors: Jinmao You, Wenjian Lao, Xuejun Sun
    Abstract:

    A sensitive LC method for the determination of amino compounds with fluorescence detection has been developed. The reaction of fluorescent tagging reagent, namely carbazole-N-(2-methyl)Acetyl Chloride (CMA-Cl), with amino acids is reported. Emission maximum for the CMA derivatives of amino acids is 360 nm (λex=335 nm). In all cases, the derivatives exhibit strong fluorescence, whereas the reagent itself also exhibits fluorescence. It is found that the labelled derivatives using CMA-Cl are very stable; <4% decomposition occurs after heating at 40°C for 24 h in neutral solution. Fluorescence intensity of amino acid derivatives is higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a gradient elution, offers baseline resolution of 18 amino acids including Orn from a linear acetonitrile gradient (here, Asn, Gln and Trp are not tested, the principal reasons: Gln and Asn, in a real sample hydrolysed, have been changed into Glu and Asp; Trp gives as much as 60% loss of its monosubstituted derivative under proposed derivatization conditions.). Separation of derivatives is carried out on a reversed-phase C18 column with good reproducibility. Derivatization and chromatographic conditions are optimized. The relative standard deviations (n=6) for 50 pmol of each amino acid derivative are <4.5%. The detection limits, calculated by the corresponding peak heights (in cm) by injecting successively lower concentrations until a signal-to-noise of 3:1, are 10–65 fmol for the labelled amino acids.

  • fluorescence properties of carbazole 9 yl Acetyl Chloride and its application for the simultaneous determination of amino acids and biogenic amines via liquid chromatography with fluorescence detection
    Analytica Chimica Acta, 1999
    Co-Authors: Jinmao You, Haitao Sun, Wenjian Lao
    Abstract:

    Abstract A rapid and sensitive derivatization method, using carbazole-9-yl-Acetyl Chloride (CRA-Cl) as derivatization reagent, for the simultaneous determination of amino acids and biogenic amines with pre-column fluorescence derivatization via liquid chromatography is investigated. The wavelength of maximum emission for the CRA derivatives is 365 nm (λex 335 nm). Fluorescence spectra of non-acyl Chloride CRA in the presence of various salts, organic halides and different surfactants are also studied. The quenching constants of NaF, NaCl, NaBr, NaI, and CH3I to CRA are 9.4, 12.6, 40.4, 56.2, and 102 M−1, respectively. Heavy atoms (above 1.0 μM) will seriously interfere with CRA emission spectra tested in the presence of halogen-salts and iodomethane. On the basis of Stern–Volmer equation for static quenching and a solute–micelle interaction linear relationship, the monomer quenching constant K of hexadecyltrimethylammonium bromide (CTMAB) to CRA is 3.0×103 M−1. The binding constants K of micelle of CTMAB and TX-100 to CRA are 5.4×103 M−1 and 2.0×103 M−1, respectively. In addition, in a kinetic analysis of CRA emission intensity (ln Iem) a linear correlation between ln Iem and 1/T was found. The slope of the working curve yields an emission stabilization energy of 17.8 kJ/mol. Derivatization and chromatographic conditions for simultaneous separation of derivatized amino acids and biogenic amines have also been optimized on a reversed-phase C18 column using a binary gradient. Studies on derivatization conditions indicate that primary and secondary amines react very fast with CRA-Cl in alkaline solution to give the corresponding fluorescent derivatives, which exhibit excellent sensitivity and stability. This method, in conjunction with a multi-gradient program, offers a complete resolution for amino acids and biogenic amines. For rapid separation of biogenic amines in plant tissue, an isocratic elution is used. Excellent response linearity is demonstrated over the injected amounts range 50–250 pmol for biogenic amines. The relative standard deviations (n=6) at an analytical concentration of pmol level are

  • high performance liquid chromatographic determination of n nitrosoamines by pre column fluorescence derivatization with acridone n Acetyl Chloride
    Talanta, 1999
    Co-Authors: Jinmao You, Xinjun Fan, Wenjian Lao, Qingcun Zhu
    Abstract:

    A sensitive high performance liquid chromatographic method for the determination of N-nitrosoamines with pre-column fluorescence derivatization has been developed. N-nitrosoamines are first changed into secondary amines using denitrosation reagent, then react with acridone-N-Acetyl Chloride (ARC-Cl) to produce corresponding secondary amine derivatives, which exhibit a strong fluorescence. Maximum emission for ARC derivatives is 430 nm (lambda(ex) 404 nm). The labelled derivatives are very stable, less than 4% decomposition occurs after heating at 40 degrees C for 24 h. Fluorescence intensities of derivatives are higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a multi-gradient program, offers a baseline resolution of the ARC derivatives from a linear acetonitrile gradient. Separation is carried out on a reverse phase C(18) column. Derivatization and chromatographic conditions are optimized. The relative standard deviation (n=6) at an analytical concentration of 10 pmol of each N-nitroamine is less than 4.5%. The detection limits at the fmol level. The method described is also suitable for analysis of other amino compounds in different biological samples.

Hamid Reza Shaterian - One of the best experts on this subject based on the ideXlab platform.