Alternating current driven atmospheric-pressure liquid discharge for the determination of elements with optical emission spectrometry

An atmospheric pressure plasma sustained by an alternating-current power supply was generated using the electrolyte solution as one electrode. The emission spectra of the plasma are related to the metal ions present in the solution and thus can be used for metal ion detection. The main advantage of this source is that it operates at low flow rates in the range of 0.1 to 0.8 mL/min. The effects of the discharge electrolyte anion, the pH and solution flow rate on emission signal were studied. The analytical response curves for Na and Cd demonstrated good linearity at least in the range of 0.5-100 mg L(-1). The limit of detection of Na and Cd were determined to be 0.04 and 0.09 mg L(-1), respectively. The method was applied for the determination of elements in simulated natural water samples (GBW(E)080408 and GBW(E)080402). The obtained results were in good agreement with the reference values. It provides an alternative analytical method for the determination of elements in water samples.