Search results for "Ninhydrin"
showing 8 items of 8 documents
Detector supports: application to aliphatic amines in wastewater
2005
Abstract Solid support assisted derivatization coupled to diffuse reflectance spectroscopy (DRS) was proposed and proved useful for the detection and quantification of aliphatic amines in water as an example. Dabsyl chloride (DBS), ninhydrin and sodium 1,2-naphtoquinone 4-sulphonate (NQS) were assayed as derivatization reagents. C 18 and SDB-XC disks and C 18 cartridges were tested for amine retention and after that derivatization. The decrease of the orange colour of dabsyl chloride on SBD-XC disks produced by the formation of its derivative with methylamine in the support (10 min at 100 °C) allowed the selective determination of the amine at concentration level equal or higher than 0.5 mg…
A comparison of various calibration techniques applied to the ninhydrin-cefoxitin determination
1996
Abstract This report deals with spectrophotometric determination of cefoxitin from intact antibiotics or from its acid induced degradation product by means of their reaction with ninhydrin in a strong sulphuric acid medium. To obtain the calibration graphs four methods were used: absorbance of reacted cefoxitin against a reagent blank as an analytical signal, first-derivative signal of absorbance against a water blank as an analytical signal, first-derivative signal of absorbance against a reagent blank as an analytical signal and the H-Point Standard Additions Method (HPSAM) by using absorbance increment values as analytical signals. The HPSAM is applied to the determination of cefoxitin i…
Comparison of several methods used for the determination of cephalosporins. Analysis of cephalexin in pharmaceutical samples
2002
The precision of UV absorbance of intact and acid degraded cephalosporins, ninhydrin, high performance liquid chromatography and iodometric methods used for analysis of cefoxitin, cefotaxime, cephazolin and cephalexin were compared. To obtain the calibration graphs the analytical signal used were: absorbance, first derivative absorbance, second derivative absorbance and H-point Standard Additions Method by using absorbance values at two selected wavelengths as analytical signal. These methods and calibration graphs were also used for the determination of cephalexin in pharmaceutical samples.
Optical recognition and removal of Hg(II) using a new self-chemosensor based on a modified amino-functionalized Al-MOF
2017
Abstract We developed a simple self-chemical optical sensor for the monitoring and removal of ultra-trace levels of Hg(II) from aqueous media. The development of this sensor was based on the covalent attachment of amino-functionalized aluminum-based MOF particles with ninhydrin. The new sensor is densely coated with a chelating ligand to permit an ultra-fast, selective, pH-dependent visualization for removal of Hg(II) with detection limit (LOD∼0.494 μg L−1). Monitoring was accomplished via both a colorimetric signal visible to the naked eye as well as UV–vis absorption spectroscopy. Digital image-based colorimetric analysis has also used as a semi-quantitative analysis for determination the…
Die Beziehung zwischen der Guanethidin-Konzentration im Rattenherzen und dem Noradrenalingehalt
1962
Guanethidine was intravenously injected into rats and was subsequently determined in the hearts by extracting the tissue with trichloroacetic acid, purifying the extracts on cation exchange columns and by paper chromatography, and coupling the guanethidine with ninhydrin in alkaline solution before fluorimetric estimation. The concentration in the heart reached a maximum of 9 μg/g within 15 min of injecting 15 mg/kg, and was still 6.2 and 5.7 μg/g after 1 and 3 hours, respectively. Guanethidine caused a decrease of the heart noradrenaline concentration, measured fluorimetrically, by 56% in 3 hours and by 93% in 14 hours. The adrenaline concentration was likewise decreased. A metabolite with…
Characterization of antimicrobial properties on the growth of S. aureus of novel renewable blends of gliadins and chitosan of interest in food packag…
2007
The biocide properties of chitosan-based materials have been known for many years. However, typical antimicrobial formulations of chitosan, mostly chitosonium salts, are known to be very water sensitive materials which may impair their use in many application fields such as food packaging or food coating applications. This first work reports on the development and characterization of the antimicrobial properties of novel fully renewable blends of chitosan with more water-resistant gliadin proteins isolated from wheat gluten. Chitosan release to the nutrient broth from a wide range of blends was studied making use of the ninhydrin method. The results indicated that both pure chitosan and its…
Conservation of amino-acid chromatograms.
1951
IN filter-paper partition chromatography, the ninhydrin reaction has been used almost exclusively for the identification and quantitative assay of amino-acids. One of the chief disadvantages of the blue pigment formed in this reaction is its rapid fading on filter-paper chromatograms. This makes it difficult to construct permanent or semi-permanent reference maps from which not only the type of amino-acid, but also the approximate quantity of the unknown mixture, can be deduced.
Synthesis of a Novel Hydrazone of Thieno[2,3-d]pyrimidine Clubbed with Ninhydrin: X-ray Crystal Structure and Computational Investigations
2023
The novel hydrazone-containing thieno[2,3-d]pyrimidine, namely, N′-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-2-(4-oxo-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-3(4H)-yl)acetohydrazide 4 was synthesized in a very good yield from the reaction of the triketoester 1 or ninhydrin 2 with the exocyclic acetohydrazide 3 in methanol. Good-quality crystals of 4 were obtained by recrystallization of the compound from the DMF/MeOH solvent mixture. The target product 4 crystallized in the triclinic crystal system and P-1 space group. The topology analysis of molecular packing indicated that the H…H (30.4%), O…H (22.0%) and H…C (17.0%) contacts are the most dominant i…