131-91-9Relevant articles and documents
Effect of GO nanosheets on spectrophotometric determination of tyrosine in urine and serum using nitrosonaphthol
Nassef, Hossam M.,Hagar, Mohamed,Othman, Abdelhameed M.
, p. 12 - 18 (2018)
Here, we aimed to use graphene oxide to improve the selectivity and sensitivity of Tyr determination via the reaction with 1-nitroso-2-naphthol as a selective reagent of Tyr. The reaction between Tyr and 1-nitroso-2-naphthol in absence and presence of GO was studied spectrophotometrically. Different parameters such as concentrations, temperature, incubation time were optimized. The obtained data showed that the maximum absorbance was achieved by using 2 mL of 0.03% 1-nitroso-2-naphthol at temperature 60 °C for 10 min. On the basis of calibration curve of various concentrations of Tyr in the presence of 20 μg mL?1 GO, the limit of detection was 6.4 × 10?6 M (1.15 μg mL?1), where in absence of GO was 1.1 × 10?5 M (19.9 μg mL?1). The selectivity of Tyr in presence of other amino acids and phenols was studied with and without GO. The data obtained revealed that the selectivity of Tyr in presence of GO with respect to some amino acids and phenols was improved. The proposed method has been applied for the determination of Tyr in urine and serum samples. Therefore, GO is a powerful catalytic surface for the sensitive and selective determination of Try in biological fluids.
Formation of mutagens by photochemical reaction of 2-naphthol in aqueous nitrite solution.
Suzuki,Watanabe,Suzuki
, p. 2204 - 2211 (1988)
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Photochromism in spiroindolinonaphthoxazine dyes: Effects of alkyl and ester substituents on photochromic properties
Partington, Steven M.,Towns, Andrew D.
, p. 123 - 130 (2014/02/14)
The impact of substituents on the photochromism of some spirooxazines has been explored. A series of photochromic spiroindolino[2,1-b][1,4]naphthoxazine dyes was prepared with varying alkyl substitution patterns in the 3- to 6-positions of the indoline system. It was found that placing methyl functions onto the phenyl ring produced bathochromic shifts in λmax of the photomerocyanine as expected, but contrary to literature indications lowered photocoloration half-life. However, replacing the 3,3-dimethyl pattern with 3-ethyl-3-methyl substitution led to more intense photochromism: half-life increased without affecting λmax. In contrast, introduction of a cyclohexyl ring to give a 3,3-pentamethylene fragment and substitution at the 5′-position of the naphthoxazine moiety with either ester or hydroxymethyl groups significantly increased the speed of fade in general contrast to literature reports for analogous dye series. Similar effects were also observed concerning alkyl substitution in a smaller synthesised set of photochromic [1,2-b][1,4]oxazines.
New nitrite ionic liquid (IL-ONO) and nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica as nitrosonium sources for electrophilic aromatic nitrosation
Valizadeh, Hassan,Amiri, Mohammad,Shomali, Ashkan
experimental part, p. 1103 - 1108 (2012/03/10)
An improved method for the synthesis of nitrosoarenes has been developed using a new nitrite ionic liquid (IL-ONO) and immobilized nitrite ionic liquid. These ionic liquids play as nitrosonium sources for electrophilic aromatic nitrosation of active aromatics at 0-5 °C. Their action was accomplished in water and the satisfactory results were obtained under the mild conditions in short reaction time.
