Selective aqueous ammonia sensors using electrochemical stripping and capacitive detection

We are currently developing pH sensitive dye doped clad modified evanescent optical fiber (CMEOF) sensor array for the detection of aqueous-ammonia. The quasi-distribution of CMEOF ammonia sensors allows efficient measurement of aqueous-ammonia at several locations using a single fiber optic line. CMEOF sensors are fabricated by immobilized pH sensitive dyes in sol-gel and applying the dye doped sol-gel as a thin film around a bare core optical fiber. The CMEOF sensors are then sealed from water using a gas permeable membrane, PDMS-vinyl. The dyes in each CMEOF sensor are tailored to operate at slightly different wavelengths by appropriate choice of dyes. Wavelength-division-multiplexing (WDM) and linear system of equations (LSE) are used to interrogate each CMEOF sensor and determine the concentration of aqueous-ammonia at each sensor location.

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CONJUGATED OESTROGENS. I

Acta Endocrinologica ◽

10.1530/acta.0.0430345 ◽

1963 ◽

Vol 43 (3) ◽

pp. 345-360 ◽

Cited By ~ 9

Author(s):

Stanley Kushinsky ◽

Jane (Wu) Tang

Keyword(s):

Molecular Weight ◽

Formic Acid ◽

Ethyl Acetate ◽

High Molecular Weight ◽

Secondary Amine ◽

Aqueous Ammonia ◽

Organic Solution ◽

Extraneous Material

ABSTRACT A convenient and mild procedure is described in this paper whereby free and conjugated oestrogens may be extracted from urine. The extracts containing approximately 90 per cent of the oestrogens are devoid of most of the extraneous material and may be reduced in volume to less than 1/15 of that of the urine. The procedure consists of the following steps: (1) a 10 per cent (v/v) solution of a high molecular weight secondary amine (Amberlite LA-2, Rohm and Haas) in ethyl acetate is washed with formic acid and water, (2) the oestrogens in urine (acidified to pH 2 or 3 with H2SO4) are extracted with the LA-2 solution, (3) the oestrogen fraction is back-extracted from the organic solution with dilute aqueous ammonia.

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ADIABATIC SPRAY ABSORPTION PROCESS IN AN AQUEOUS AMMONIA SOLUTION

Heat Transfer Research ◽

10.1615/heattransres.2013005214 ◽

2013 ◽

Vol 44 (8) ◽

pp. 733-743

Author(s):

Fengmin Su ◽

Yangbo Deng ◽

Hongbin Ma

Keyword(s):

Aqueous Ammonia ◽

Ammonia Solution ◽

Absorption Process ◽

Aqueous Ammonia Solution ◽

Spray Absorption

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Mild Temperature Copper-Catalyzed Amination of Aryl Halides with Aqueous Ammonia in the Presence of Pyridyldiketone Ligands

10.26434/chemrxiv.7756886.v1 ◽

2019 ◽

Author(s):

Racha Abed Ali Abdine ◽

Anna Walczak ◽

Sultan Abu A Aeash ◽

Gracjan Kurpik ◽

Artur R. Stefankiewicz ◽

...

Keyword(s):

Catalytic System ◽

Aqueous Ammonia ◽

Aryl Halides ◽

Efficient Coupling ◽

Ambidentate Ligand ◽

Mild Temperature

Ambidentate ligand pyridyldiketones were used in combination with copper to catalyze maintain of aryl halides under very mild temperatures. This novel catalytic system allow efficient coupling in one of the smoothest conditions ever reported in literature.

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