A gas-diffusion flow injection method coupled with online solid–liquid extraction for the determination of ammonium in solid samples

Abstract

A simple, rapid and reliable gas-diffusion flow injection (GD-FI) method for ammonium determination in building materials has been developed. It is based on leaching ammonium from a ground solid sample into an alkaline solution with subsequent ammonia gas generation. Ammonia is then transported in a nitrogen stream to the GD cell of the FI system where it is absorbed into its acceptor solution containing a mixture of the acid-base indicators cresol red and thymol blue. The maximum increase in the absorbance of the acceptor solution at 580 nm is related to the ammonium concentration in the solid sample. The proposed method is characterized by a linear concentration range of 0.1-5.0 mg NH4(+) kg(-1), a limit of detection of 8 μg NH4(+) kg(-1) and a sample throughput of 10h(-1). A successful application of this method for the determination of ammonium in building materials such as concrete, cement and sand is reported.

Automatic On-Line Purge-and-Trap Sequential Injection Analysis for Trace Ammonium Determination in Untreated Estuarine and Seawater Samples

“…In the following steps (11)(12)(13), the trapping solution is delivered and "parked" in the holding coil HC-2, by the operation of SP1. Then, a small segment of 40 µL is aspirated through port 4 of the COV, into miniSIA analyzer for fluorimetric quantification.…”

Colorimetric Determination of Sulfide in Turbid Water with a Cost-effective Flow-batch Porous Membrane-based Diffusion Scrubber System

“…19 Timofeeva et al reported an adapted gas-diffusion chamber with a membrane to connect with a flow injection analysis (GD-FIA) system for ammonium determination in building materials. 20 The method is based on the generation of ammonia gas from a solid sample by adding a basic solution. The NH3 gas was carried by N2 gas and dissolved into cresol red and thymol blue as an acceptor solution, and finally, the absorbance of the acceptor solution was detected at 580 nm to quantify the NH4 + .…”

Ultrafast capillary electrophoresis method for the simultaneous determination of ammonium and diphenhydramine in pharmaceutical samples

“…Methods for determination of NH 4 + are mainly based on spectrophotometry , fluorometry , chemiluminescence , conductometry , potentiometry , and amperometry . DIP is predominantly determined by LC , the most commonly employed technique for pharmaceuticals analysis, and some CE methods .…”

“…Medications containing DIP and NH 4 + are popular and widely consumed, and, therefore, a method for the determination of both compounds in a single run is highly desirable. Methods for determination of NH 4 + are mainly based on spectrophotometry [6][7][8], fluorometry [9], chemiluminescence [10,11], conductometry [12,13], potentiometry [14,15], and amperometry [16][17][18][19]. DIP is predominantly determined by LC [20][21][22][23][24], the most commonly employed technique for pharmaceuticals analysis, and some CE methods [25][26][27][28].…”