Radiofrequency driven and low cost fabricated microhollow cathode discharge for gaseous atomic emission spectrometry

Abstract

The current research presents a microhollow cathode discharge (MHCD) used as an analytical microplasma gas detector combining the advantages of a hollow cathode geometry in a miniaturized system offering atmospheric pressure operation. The plasma is driven by a homemade resonant radiofrequency generator (f = 1–10 MHz) reducing the electrode sputtering by a factor of 6.5 compared to common direct current operation leading to an extension of the lifetime of the microplasma chip of the same range. This paper aims further for the development of a novel low priced and therefore replaceable MHCD chip exchanging formerly used Pt electrodes by thin Cu electrodes. The analytical performance of the low cost Cu-MHCD with lifetime enhancing radiofrequency operation is demonstrated by atomic emission spectrometry with halogenated hydrocarbons with the Cl emission line at 912.114 nm. This leads to an excellent detection limit of 15 ppb v/v gaseous Cl in He making this microplasma chip suitable for lab on a chip application.