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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.

The simple and easy performed automated method for the IR determination of petroleum products (PP) in water using extraction-chromatographic cartridges has been developed. The method assumes two stages: on-site extraction of PP during a sampling by using extraction-chromatographic cartridges and subsequent determination of the extracted PP using sequential injection analysis (SIA) with IR detection. The appropriate experimental conditions for extraction of the dissolved in water PP and for automated SIA procedure were investigated. The calibration plot constructed using the developed procedure was linear in the range of 3–200 μg L −1 . The limit of detection (LOD), calculated from a blank test based on 3σ was 1 µg L −1 . The sample volume was 1 L. The system throughput was found to be 12 h −1 .

Simple, rapid and fully automated methods for the manual and automated spectrophotometric determination of epinephrine have been developed by using schemes of stepwise injection (SWIA) and sequential injection analysis (SIA) implemented in the same manifold. The determination is based on the formation of reduced form of 18-molybdodiphosphate heteropoly anion by its reaction with epinephrine. Using of the reaction vessel in the general SWIA configuration instead of a holding and reaction coil in the SIA manifold provides several essential advantages, including higher sensitivity and lower reagent consumption. The linear dependence of the analytical signal on the epinephrine concentration was preserved over the range of 1.5–30, 3.0–30, and 1.5–25 μmol L −1 by using of SWIA, SIA and spectrophotometric analysis, respectively. The relative standard deviation for the SWIA determination of 10 μmol L −1 epinephrine was 1.8% ( n =10).