Merck
  • Home
  • Search Results
  • Development of a polydimethylsiloxane-thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water samples.

Development of a polydimethylsiloxane-thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water samples.

The Science of the total environment (2014-08-13)
M C Prieto-Blanco, N Jornet-Martínez, Y Moliner-Martínez, C Molins-Legua, R Herráez-Hernández, J Verdú Andrés, P Campins-Falcó
ABSTRACT

This report describes a polydimethylsiloxane (PDMS)-thymol/nitroprusside delivery composite sensor for direct monitoring of ammonium in environmental water samples. The sensor is based on a PDMS support that contains the Berthelot's reaction reagents. To prepare the PDMS-thymol/nitroprusside composite discs, thymol and nitroprusside have been encapsulated in the PDMS matrix, forming a reagent release support which significantly simplifies the analytical measurements, since it avoids the need to prepare derivatizing reagents and sample handling is reduced to the sampling step. When, the PDMS-thymol/nitroprusside composite was introduced in water samples spontaneous release of the chromophore and catalyst was produced, and the derivatization reaction took place to form the indothymol blue. Thus, qualitative analysis of NH4(+) could be carried out by visual inspection, but also, it can be quantified by measuring the absorbance at 690 nm. These portable devices provided good sensitivity (LOD<0.4 mg L(-1)) and reproducibility (RSD <10%) for the rapid detection of ammonium. The PDMS-NH4(+) sensor has been successfully applied to determine ammonium in water samples and in the aqueous extracts of particulate matter PM10 samples. Moreover, the reliability of the method for qualitative analysis has been demonstrated. Finally, the advantages of the PDMS-NH4(+) sensor have been examined by comparing some analytical and complementary characteristics with the properties of well-established ammonium determination methods.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
硅油, for oil baths (from −50°C to +200°C)
Sigma-Aldrich
硝普钠 二水合物, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99%
Sigma-Aldrich
麝香草酚, ≥98.5%
Sigma-Aldrich
硅油, viscosity 5 cSt (25 °C)
Sigma-Aldrich
硅油, viscosity 10 cSt (25 °C)
Sigma-Aldrich
硝普钠 二水合物, ACS reagent, ≥99%
Sigma-Aldrich
硅油, viscosity 20 cSt (25 °C)
Sigma-Aldrich
硅油, viscosity 1,000 cSt (25 °C)
Sigma-Aldrich
硅油, Dow Corning 200® fluid, viscosity 60,000 cSt (25 °C)
Sigma-Aldrich
麝香草酚, meets analytical specification of Ph. Eur., BP, NF, 99-101%
Sigma-Aldrich
硅油, viscosity 100 cSt (25 °C)
硅油, for melting point and boiling point apparatuses
Sigma-Aldrich
硅油, viscosity 350 cSt (25 °C)
Sigma-Aldrich
麝香草酚, FCC, FG
Sigma-Aldrich
硅油, viscosity 10,000 cSt (25 °C)
Supelco
硝普钠, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
麝香草酚, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
硅油, viscosity 50 cSt (25 °C)
Sigma-Aldrich
硅油, viscosity 500 cSt (25 °C)
Supelco
麝香草酚, analytical standard
硅油, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
硅油, viscosity 100,000 cSt (25 °C)
Sigma-Aldrich
硅油, viscosity 30,000 cSt (25 °C)
麝香草酚, European Pharmacopoeia (EP) Reference Standard
麝香草酚, primary reference standard