0000000000587592
AUTHOR
J. Verdú Andrés
Development of a polydimethylsiloxane–thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water samples
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…
Determination of ammonia and primary amine compounds and Kjeldahl nitrogen in water samples with a modified Roth's fluorimetric method.
Abstract A method for the simultaneous determination of primary amino groups and ammonium ion has been proposed. The method is based in solution derivatization with o-Phthaldialdehyde/N-acetyl-cisteine (OPA/NAC) and fluorescence measurement of the formed isoindols. Analytical characteristics and description of the developed procedure have been provided. The calibration graphs for ammonium (up to 1.44 mg L−1 of N) and methylamine as primary amino model compound (up to 0.282 mg L−1 of N), were obtained. Bivariate and multivariate calibration models have been tested. The limits of detection were 0.07 mg L−1 of N and 0.004 mg L−1 of N for ammonium and amine, respectively. The procedure was firs…
Sensitive determination of aliphatic amines in water by high-performance liquid chromatography with chemiluminescence detection.
A sensitive method has been developed for liquid chromatographic determination of short aliphatic amines in water samples. Analytes are preconcentrated and dansylated on solid sorbents (C18 solid-phase extraction cartridges). The dansyl derivatives are chromatographed and post-column mixed with peroxyoxalate (TCPO) and H2O2 in order to perform chemiluminescence detection. Optimal results have been obtained using a sample volume of 5 ml. The method has been applied to the quantification or screening of several aliphatic amines: methylamine, ethylamine, butylamine, diethylamine, pentylamine and hexylamine. The screening procedure has been developed including also polyamines (putrescine, cadav…
Evaluation of C18 adsorbent cartridges for sampling and derivatization of primary amines in air
Abstract The sampling efficiency of C18 solid-phase extraction cartridges was investigated for methylamine, ethylamine, propylamine, butylamine and pentylamine, in air. Determination of these analytes was based on derivatization with o-phthaldialdehyde–N-acetylcysteine (OPA–NAC) on the solid support and fluorescence detection at λexcitation=330 nm and λemission=440 nm of the eluted derivatives. The calibration model derived from aqueous standards was statistically comparable with the calibration model for air standards. Aqueous amines can be used as standards. The method was useful for calculating short-term exposure limits (STEL). A sampling time of 15 min at 30 ml min−1 was employed. Good…