Automated procedure for determination of ammonia in concrete with headspace single-drop micro-extraction by stepwise injection spectrophotometric analysis

Abstract

A novel automatic stepwise injection headspace single-drop micro-extraction system is proposed as a versatile approach for automated determination of volatile compounds. The system application is demonstrated for ammonia determination in concrete samples. An ammonia gas was produced from ammonium ions and extracted on-line into 5 μL 0.1M H3PO4 to eliminate the interference effect of concrete species on the ammonia stepwise injection spectrophotometric determination. The linear range was 0.1-1 mg kg(-1) with LOD 30 µg kg(-1). The sample throughput was 4 h(-1). This system has been successfully applied for the determination of ammonia in concretes.

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

“…As previously reported [23], efficient leaching of ammonium from concrete samples required sonication of the alkaline concrete suspension in an ultrasonic bath. The effect of the duration of the stopflow time with sonication of the sample suspension on ammonium recovery was studied in the range between 1 and 15 min using spiked with ammonium concrete samples (2.5 mg NH 4 + kg À 1 ).…”

“…Comparison of the analytical performance of the proposed method with the SWIA-HSDME method for ammonium determination in concrete samples, developed earlier by us [23].…”

“…salicylate) [20][21][22]. This approach has been applied earlier by us in the development of an automatic flow analysis method for the determination of ammonium in concrete samples [23]. This method is based on headspace single-drop micro-extraction of ammonia followed by stepwise injection spectrophotometric analysis (SWIA-HSDME) based on the Berthelot reaction.…”

“…In GD separation the donor stream is also in direct contact with the membrane while in pervaporation separation there is an air gap between the membrane and the donor stream which prevents potential deterioration in the membrane permeability by surfactants, corrosive compounds or micrometer size particulates in the sample matrix. This paper reports on the development and validation of a GD-FI method for the determination of ammonium in building materials such as concrete, cement and sand which is faster and simpler than the SWIA-HSDME [23] mentioned above.…”

A fully automated effervescence assisted dispersive liquid–liquid microextraction based on a stepwise injection system. Determination of antipyrine in saliva samples

“…The stepwise injection analysis [25][26][27][28][29] was chosen for this purpose. The extraction procedure has been optimized and applied for the determination of antipyrine in saliva samples.…”