Ion pair-based liquid-phase microextraction combined with cuvetteless UV–vis micro-spectrophotometry as a miniaturized assay for monitoring ammonia in waters

Senra-Ferreiro, Sonia; Pena‐Pereira, Francisco; Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos

doi:10.1016/j.talanta.2011.06.030

Cited by 13 publications

(1 citation statement)

References 26 publications

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“…The ammonia gas entrained in the CO 2 effluent was adsorbed by dilute sulphuric acid (0.025 M) to generate ammonium sulfate. The ammonium ion was then transformed into indophenol blue and analyzed quantitatively by UV/vis spectrophotometry. , Absorbance was measured in the wavelength of 697 nm, and the NH 3 concentration can be obtained according to the Beer–Lambert law. The amounts of organic compounds could be determined by GC analysis.…”

Section: Methodsmentioning

confidence: 99%

CO₂/Water-Regulating Transamidation of Urea and Amines

Zhang

Guo

Chen

et al. 2014

ACS Sustainable Chem. Eng.

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The process of urea transamidation with amine to urea derivative has been developed in the presence of both carbon dioxide and water. Through the present reaction route, not only can the urea derivatives be obtained in high yield, but also inorganic salt ammonium bicarbonate (ABic) can be successfully isolated simultaneously from the reaction mixture. The phase behavior observed in situ by high pressure visual autoclave illustrated that the reaction occurred in biphasic conditions during the reaction. A number of verifying tests were conducted to investigate the role of carbon dioxide and water in the system. It was found that reaction temperature, total pressure, reaction time, and water played a crucial role in producing urea derivatives. The further investigation showed that the transamidation reaction between various amines and urea occurred successfully without the addition of any other catalysts in the presence of CO 2 and water. The acidity resulting from reaction of CO 2 with water facilitated the transamidation reaction.

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Section: Methodsmentioning

confidence: 99%