Liquid Cathode Glow Discharge as an Excitation Source for the Analysis of Complex Water Samples with Atomic Emission Spectrometry

Abstract

A liquid cathode glow discharge (LCGD) was developed as a low-power and miniaturized excitation source of atomic emission spectrometry (AES) for the determination of K, Na, Ca, and Mg in water samples from rivers and lakes. The discharge stability and parameter influencing the analytical performance of LCGD-AES were systematically examined. Moreover, the measurement results of water samples using LCGD-AES were verified by ion chromatography (IC). The results showed that the optimized operating parameters are a 660 V discharge voltage, pH = 1.0 HNO 3 as the supporting electrolyte, and a 4.0 mL min –1 solution flow rate. High concentrations of some metals may interfere with the detection of Ca and Mg. Low-molecular-weight organic substances do not have a remarkable enhancement on signal intensity. With the addition of 0.5% cetyltrimethylammonium chloride (CTAC), the emission intensity of elements can enhance significantly. However, it is not used to further evaluate the analytical performance due to instability of plasma after adding CTAC. The maximum power of LCGD is 52 W. The limits of detection and precision (RSD, in 1 mg L –1 ) of K, Na, Ca, and Mg are 0.20, 0.02, 0.01, and 0.01 mg L –1 and 0.9, 1.5, 0.6, and 1.2%, respectively. The measurement results of K, Na, Ca, and Mg in water samples by LCGD-AES are basically in agreement with the reference values measured by IC. The recovery of samples ranged from 84 to 113% except for Na, suggesting that the measurement results have high accuracy and reliability. All the results indicated that the LCGD-AES can provide an alternative analytical method for in situ, real-time, on-line determination of K, Na, Ca, and Mg in water samples from rivers and lakes.

Fast and simple analysis of the content of Zn, Mg, Ca, Na, and K in selected beverages widely consumed by athletes by flowing liquid cathode atmospheric pressure glow discharge optical emission spectrometry

“…In this case, the inorganic matrix was not expected to be an issue since, firstly, the studied samples did not contain much of it, and secondly the FLC-APGD system was repeatedly proven to be relatively resistant to it. 30,31,50,54,55 However, the samples analyzed in this study contained more of the organic matrix (depending on the sample), which differed between them. Considering all these facts, it was established optimization of the sample dilution is needed to evaluate its impact on both the discharge stability and the linearity of the analyte signal response.…”

Development of milli-second pulsed atmospheric pressure solution cathode glow discharge optical emission spectroscopy for detecting metal elements in aqueous solution

“…For comparison, the LOD from SCGD with a 0.65T magnetic field, 34 liquid cathode glow discharge atomic emission spectrometry (LCGD-AES), 35 liquid sampling-atmospheric pressure glow discharge (LS-APGD), 36 pulsed electrolyte cathode discharge (pulsed-ELCAD), 37 atmospheric pressure glow micro discharge (μAPGD), 38 and hollow anode-solution cathode glow discharge (HA-SCGD) 39 studies are also listed. It is obvious that the proposed pulsed-SCGD method (with the detection limits of 0.080, 0.050, 3.4, 64, 69, 9.1, and 2.0 μg L −1 , respectively for Na, K, Cu, Co, Cd, Mn, and Ag) has performed well compared to previously reported methods.…”

Biological applications of chiral inorganic nanomaterials

“…93 Hence, it is essential to detect metal ions. Various methods, such as inductively coupled plasma mass spectrometry (ICP-MS), 94 atomic emission spectrometry, 95 and chemiluminescence, 96 have been widely used in the detection of metal ions. However, sophisticated equipment, time-consuming treatment, and complex operation route has limited the application of these methods.…”