Computer-controlled fluid-flow chemical analysis (CC-FCA) and its application to environmental analytical chemistry

2012 ◽  
Vol 84 (10) ◽  
pp. 1999-2013 ◽  
Author(s):  
Shoji Motomizu
Keyword(s):  
Fluid Flow ◽  
Chemical Analysis ◽  
Water Samples ◽  
Type System ◽  
Environmental Water ◽  
Sequential Injection ◽  
System A ◽  
Injection Type ◽  
Computer Controlled

Computer-controlled fluid-flow chemical analysis (CC-FCA) was investigated for the determination of trace amounts of toxic pollutants in the environment. For CC-FCA, automated chemical analysis systems were developed by using computer-controllable pumping and valve modules, and polytetrafluorethylene (PTFE) tubing and connectors. The systems demonstrated in this work were a flow injection-type system, a sequential injection-type system, a mini-column pretreatment system (Auto-Pret system), and an Auto-Pret hyphenated with flow injection analysis (FIA) system. Such systems were fully controlled by a computer program; the lab-made programs were written in Visual Basic. The systems can be hyphenated with some detectors, such as a spectrophotometric detector, an electrochemical detector, electrothermal-atomic absorption spectrometry (ET-AAS), a liquid electrode plasma-atomic emission spectrometry (LEP-AES) and inductively coupled plasma (ICP)-AES. Such systems were successfully applied to the determination of trace amounts of toxic pollutants in environmental water samples: they were heavy metal ions (Pb, Cd, Cr, etc.). In this paper, the author aims mainly at investigating the CC-FCA method for the determination of trace amounts of Cr(VI) in environmental water samples by spectrophotometry. The techniques used in this work were FIA, sequential injection analysis (SIA), and Auto-Pret/FIA, which were all computer-controllable. Limits of detection of Cr(VI) by FIA, SIA, and Auto-Pret/FIA were 8 × 10–9 mol/L (0.4 μg/L), 1.1 × 10–8 mol/L (0.6 μg/L), and 1.4 × 10–9 (0.07 μg/L), respectively. The methods were applied to the determination of Cr(VI) in river and drinking waters.

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

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1569
Author(s):  
Athina Dimitriadou ◽  
Aristidis Anthemidis
Keyword(s):  
Water Samples ◽  
Environmental Water ◽  
Sequential Injection Analysis ◽  
Gaseous Ammonia ◽  
Sequential Injection ◽  
Fluorimetric Determination ◽  
Purge And Trap ◽  
Separation And Preconcentration ◽  
On Line ◽  
T System

An innovative automatic purge-and-trap (P&T) system coupled with fluorimetric sequential injection (SI), for the on-line separation and preconcentration of volatile compounds, is presented. The truth of concept is demonstrated for the ammonium fluorimetric determination in environmental water samples with complex matrices without any pretreatment. The P&T flow system comprises a thermostated purge-vessel where ammonium is converted into gaseous ammonia and a trap-vessel for ammonia collection. This configuration results in matrix removal as well as analyte preconcentration, avoiding membrane-associated problems. All the main parameters affecting the efficiency of a P&T system were studied and optimized. The proposed method is characterized by a working range of 2.7–150.0 μg L−1 of NH4+, with a detection and quantification limit of 0.80 and 2.66 μg L−1, respectively, for a 10-mL sample consumption. The accuracy of the method was assessed by recovery assays in seawater, estuarine, and lake water samples as well as by the analysis of standard reference material.

scholarly journals Fast UHPLC-MS/MS for the Simultaneous Determination of Azithromycin, Erythromycin, Fluoxetine and Sotalol in Surface Water Samples

2021 ◽  
Vol 11 (18) ◽  
pp. 8316
Author(s):  
Mira Azzi ◽  
Sylvain Ravier ◽  
Assem Elkak ◽  
Bruno Coulomb ◽  
Jean-Luc Boudenne
Keyword(s):  
Surface Water ◽  
Simultaneous Determination ◽  
Surface Waters ◽  
Water Samples ◽  
High Performance ◽  
Chemical Properties ◽  
Environmental Water ◽  
Butyl Ether ◽  
Flight Mass Spectrometry

Chromatographic development for the determination of pharmaceuticals in environmental water samples is particularly challenging when the analytes have significantly different physico-chemical properties (solubility, polarity, pKa) often requiring multiple chromatographic methods for each active component. This paper presents a method for the simultaneous determination of azithromycin, erythromycin (antibiotics), fluoxetine (anti-depressant) and sotalol (b-blocker) in surface waters by ultra-high-performance liquid chromatography coupled with ultra-high-resolution time-of-flight mass spectrometry. These pharmaceuticals—presenting a broad spectrum of polarity (0.24 ≤ log Kow ≤ 4.05)—were separated on a C-18 analytical column, after a simple filtration step for freshwater samples or after a liquid–liquid extraction with Methyl-tertio-butyl ether (MTBE) for seawater samples. The optimized separation method (in terms of nature of column and eluent, elution gradient, and of mass spectrometric parameters), enable one to reach limits of detection ranging between 2 and 7 ng L−1 and limits of quantification between 7 and 23 ng L−1 for the four targeted molecules, within a three minute run. This method was validated using samples collected from three different surface waters in Lebanon (freshwater and seawater) and analytical results were compared with those obtained in surface waters sampled in a French river, equivalent in terms of human activities. Using this method, we report the highest concentration of pharmaceuticals found in surface water (up to 377 ng L−1 and 268 ng L−1, respectively, for azithromycin and erythromycin, in the Litani river, Lebanon).

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