Flowing Liquid Anode Atmospheric Pressure Glow Discharge as an Excitation Source for Optical Emission Spectrometry with the Improved Detectability of Ag, Cd, Hg, Pb, Tl, and Zn

Abstract

A novel atmospheric pressure glow discharge generated in contact with a flowing liquid anode (FLA-APGD) was developed as the efficient excitation source for the optical emission spectrometry (OES) detection. Differences in the appearance and the electrical characteristic of the FLA-APGD and a conventional system operated with a flowing liquid cathode (FLC-APGD) were studied in detail and discussed. Under the optimal operating conditions for the FLA-APGD, the emission from the analytes (Ag, Cd, Hg, Pb, Tl, and Zn) was from 20 to 120 times higher as compared to the FLC-APGD. Limits of detections (LODs) established with a novel FLA-APGD system were on average 20 times better than those obtained for the FLC-APGD. A further improvement of the LODs was achieved by reducing the background shift interferences and, as a result, the LODs for Ag, Cd, Hg, Pb, Tl, and Zn were 0.004, 0.040, 0.70, 1.7, 0.035, and 0.45 μg L(-1), respectively. The precision of the FLA-APGD-OES method was evaluated to be within 2-5% (as the relative standard deviation of the repeated measurements). The method found its application in the determination of the content of Ag, Cd, Hg, Pb, Tl, and Zn in a certified reference material (CRM) of Lobster hepatopancreas (TORT-2), four brass samples as well as mineral water and tea leaves samples spiked with the analytes. In the case of brass samples, a reference method, i.e., inductively coupled plasma optical emission spectrometry (ICP-OES) was used. A good agreement between the results obtained with FLA-APGD-OES and the certified values for the CRM TORT-2 as well as the reference values obtained with ICP-OES for the brass samples was revealed, indicating the good accuracy of the proposed method. The recoveries obtained for the spiked samples of mineral water and tea leaves were within the range of 97.5-102%.

Rapid eradication of bacterial phytopathogens by atmospheric pressure glow discharge generated in contact with a flowing liquid cathode

“…It was established that temperature of bacterial suspensions increased following dc‐APGD treatment to 40.2 °C (10 min post dc‐APGD treatment) as compared to 24.2 °C before such treatment. The noted temperature change was in agreement with observations of Greda et al () on a similar flow‐through system. Therefore, the effect of 1‐min and 20‐min exposure of tested bacteria to 40 °C and 60 °C was determined.…”

“…Plasma‐chemical parameters of dc‐APGD such as T rot (N 2 ), T rot (OH), T vib (N 2 ), T exc (H) as well as n e were assessed to define plasma properties and its elementary processes. T rot (N 2 ) is related to kinetic plasma gas temperature (Greda et al, ). Based on fitting of the N 2 emission spectrum to the simulated vibration‐rotational emission spectrum of this molecule, T rot (N 2 ) value at the plasma‐liquid interfacial zone was estimated to be 2,300 ± 100 K, which is significantly higher than what has been reported for DBD‐based plasma devices previously used for biological applications (Shen et al, ; Tiede et al, ).…”

High-Sensitivity Determination of K, Ca, Na, and Mg in Salt Mines Samples by Atomic Emission Spectrometry with a Miniaturized Liquid Cathode Glow Discharge

“…Unfortunately, it is difficult to judge the cause of this type of interference. Certainly, this is related to a complex and unexplained mechanism for the release of the analytes from the surface of the flow solution [ 23 ].…”

“…In recent years, closed-type ELCAD has been applied for the analysis of several real samples including water samples [ 18 , 23 ], human hair and stream sediment [ 24 ], honeys [ 25 ], tuna fish and aquatic plant [ 26 ], titanium dioxide [ 27 ], zircaloys [ 28 , 29 ], colloidal silica [ 5 ], and soils and spruce needles [ 11 ]. Despite these progresses, to the best of our knowledge, ELCAD type is rarely applied for the determination of metal elements in salt mines samples, perhaps because of its complicated matrix.…”

Direct current atmospheric pressure glow discharge generated between a pin‐type solid cathode and a flowing liquid anode as a new tool for silver nanoparticles production

“…Due to low operating costs, high effectiveness, and lack of toxic compounds, PLIs based methods have become an interesting and attractive alternative approach to AgNPs and AuNPs production. Their use in nanomaterials synthesis only depends on generation of different reactive species, for example, hydrated electrons , hydrogen ions (H + ), hydrogen radicals (H), hydroxyl radicals (OH • ) and hydrogen peroxide (H 2 O 2 ), and other phenomena occurring at the plasma‐liquid interface and being responsible for suitable reducing conditions for the metallic nanoparticles precursors . Introduction of the additional reducing agents in such plasma‐reaction systems is completely unnecessary, hence, operational costs are highly decreased, while the whole nanomaterials synthesis is simplified …”