Determination Of Amino Compounds Research Articles

A Novel Method for the Assay of Metoprolol by Visible Spectrophotometry using Cobalt Thiocyanate

Metoprolol tartrate (MPT) is a selective β1 receptor blocker drug mostly administered in cardiovascular diseases. Due to the highly probable over dosage, a rapid and easy to perform method for the quantitative determination of MPT in biological matrices would be useful in its therapeutic monitoring as well as in intoxication cases. The study presents a validated method for the U.V.-VIS quantitative assay of MPT in bulk and tablet formulations at λmax of 625 n.m. with molar absorptivity of 1.705 × 103 L. mole-1 cm-1 . The parameters targeted for the validation were: linearity, sensitivity, accuracy and precision. The presence of secondary amine group in MPT molecule is the basis for the proposed visible spectrophotometric method. Cobalt Thiocyanate (CTC) has been proved to be a valuable chromogenic reagent for the detection and determination of amino compounds. The coloured species formed is the coordination complex of the drug and the central metal atom of CTC, which is extractable into nitrobenzene from aqueous solution. Formation of blue coloured complex when MPT is treated with CTC due to the presence of secondary amine group in it is the basis in the present investigation. The developed method is more selective, sensitive, reproducible, rapid, cheap and simple than in most of the analogous methods. For these reasons, it can be used in routine analysis and can be applied for the determination of MPT in pharmaceutical formulations and biological samples

Qualitative and quantitative analysis of the amino acids in Rhizoma Arisaematis by ultra high performance liquid chromatography-tandem mass spectrometry and high performance liquid chromatography

A method for the identification and determination of the polar amino components without ultraviolet activity in traditional Chinese medicines was developed. With Rhizoma Arisaematis as the object of this study, using pre-column derivatization with phenyl isothiocyanate (PITC) as the derivatization reagent, compounds were separated and identified on a C18 column (100 mm x 2.1 mm, 3.5 µm) by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A total of 20 components, including 18 amino acids and 2 amine compounds were identified. Furthermore, after the optimization of the derivatization conditions, 15 amino acids were determined by high performance liquid chromatography (HPLC) on Diamonsil C18 column (250 mm x 4.6 mm, 5 µm), detected at 254 nm and gradiently eluted by acetonitrile and 0. 05 mol/L ammonium acetate-acetic acid (pH 6. 5) as the mobile phases. The results of methodological study demonstrated that the method can meet the requirements of the determination. All calibration curves expressed good linearity: Glu, Try in the range of 2-100 mg/L, Arg in the range of 6-300 mg/L, others in the range of 0. 8-40 µg/L, with the correlation coefficients ≥ 0. 999 5. The average recovery of this method was among 95%-105% and the RSD was less than 3%. The developed method was successfully applied to quantitative determination of amino compounds in 12 batches of Rhizoma Arisaematis samples. The method is simple, sensitive, accurate, and can be used for rapid identification and determination of amino components in traditional Chinese medicines.

The Determination of Amino-Compounds Occurring as Impurities in Pharmaceutical Chemicals: Part II.: 3-Amino-4-Hydroxyphenylarsonic Acid in Acetarsol

Summary A method has been evolved for the determination of small amounts of 3-amino-4-hydroxyphenylarsonic acid in acetarsol. The official limit test has been examined by photoelectric methods and the actual limit determined. A more satisfactory test is proposed.

6,7-Difluoro-1,4-dihydro-1-methyl-4-oxo-3-quinolinecarboxylic Acid, a Newly Designed Fluorescence Enhancement-Type Derivatizing Reagent for Amino Compounds

A novel fluorescence enhancement-type derivatizing reagent for amino compounds, 6,7-difluoro-1,4-dihydro-1-methyl-4-oxo-3-quinolinecarboxylic acid (FMQC), was developed. FMQC reacts with aliphatic primary amino compounds to afford strong fluorescent derivatives having high photo-and thermo-stabilities. The FMQC derivatives of amino compounds showed 12-159 times higher fluorescence quantum efficiencies than those of FMQC in aqueous and polar organic media. Additionally, the absorption and fluorescence emission wavelength of the derivatives are red-shifted from those of FMQC. These differences in the fluorescence properties between FMQC and the fluorescent derivative enabled the simple and highly sensitive determination of amino compounds without removing any excess unreacted FMQC by using a simple spectrofluorometer as well as HPLC.

Graphite Composite Electrode in Voltammetry

Graphite composite electrode (CCE30), composed from 30% of graphite powder and 70% of epoxy resin, was tested. Determination of aminocompounds, oxidation of adenine and guanine, and determination of manganese by differential pulse voltammetry (DPV) and direct current voltammetry (DCV) was tested in positive potential area.

Analytical potential of 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein for the determination of amino compounds by capillary electrophoresis with laser-induced fluorescence detection

The analytical potential of a fluorescein analogue, 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein (SAMF), for the first time synthesized in our laboratory, as a labeling reagent for the labeling and determination of amino compounds by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was investigated. Biogenic monoamines and amino acids were chosen as model analytes to evaluate the analytical possibilities of this approach. The derivatization conditions and separation parameters for the biogenic amines were optimized in detail. The derivatization was performed at 30 degrees C for 6 min in boric acid buffer (pH 8.0). The derivatives were baseline-separated in 15 min with 25 mM boric acid running buffer (pH 9.0), containing 24 mM SDS and 12.5% v/v acetonitrile. The concentration detection limit for biogenic amines reaches 8 x 10(-11) mol.L(-1) (signal-to-noise ratio = 3). The application of CE in the analysis of the SAMF-derivatized amino acids was also exploited. The optimal running buffer for amino acids suggested that weak acidic background electrolyte offered better separation than the basic one. The proposed method was applied to the determination of biogenic amines in three different beer samples with satisfying recoveries varying from 92.8% to 104.8%. Finally, comparison of several fluorescein-based probes for amino compounds was discussed. With good labeling reaction, excellent photostability, pH-independent fluorescence (pH 4-9), and the resultant widely suited running buffer pH, SAMF has a great prospect in the determination of amino compounds in CE.

CARBAZOLE-9-N-ACETYL-N-HYDROXYSUCCINIMIDE (CAHS) AS PRE-COLUMN DERIVATIZATION AGENT FOR FLUORIMETRIC DETECTION OF AMINO COMPOUNDS WITH LIQUID CHROMATOGRAPHY

A simple and sensitive LC method for the determination of amino compounds, using carbazole-N-acetyl-N-hydroxy-succinimide (CAHS) as condensation agent, has been developed.A mixture of amines is treated with CAHS, in the presence of triethylamine catalyst in non-aqueous acetonitrile or in the presence of 0.2 M borate buffer at pH 8.0–9.0 in 40% (v/v) of acetonitrile solution, to give quantitative yields of amides. Emission maximum for the derivatized amines is 365 nm (λex 335 nm). Studies on derivatization conditions indicate that amines react very fast with CAHS under proposed conditions. The method, in conjunction with a multi-step gradient, offers baseline resolution of common amine derivatives on a reversed-phase C18 column. Derivatization reaction is more convenient and more efficient than previous methods which require prior conversion of carboxylic acids to acyl chlorides. The LC separation of amine derivatives has good reproducibility. The established method is also suitable for the determination of other amines in various biological fluids.