Miniaturized Dielectric Barrier Discharge Carbon Atomic Emission Spectrometry with Online Microwave-Assisted Oxidation for Determination of Total Organic Carbon

A simple, rapid, and portable system consisted of a laboratory-built miniaturized dielectric barrier discharge atomic emission spectrometer and a microwave-assisted persulfate oxidation reactor was developed for sensitive flow injection analysis or continuous monitoring of total organic carbon (TOC) in environmental water samples. The standard/sample solution together with persulfate was pumped to the reactor to convert organic compounds to CO2, which was separated from liquid phase and transported to the spectrometer for detection of the elemental specific carbon atomic emission at 193.0 nm. The experimental parameters were systematically investigated. A limit of detection of 0.01 mg L-1 (as C) was obtained based on a 10 mL sample injection volume, and the precision was better than 6.5% (relative standard deviation, RSD) at 0.1 mg L-1. The system was successfully applied for TOC analysis of real environmental water samples. The obtained TOC value of 30 test samples agreed well with those by the standard high-temperature combustion coupled nondispersive infrared absorption method. Most importantly, the system showed good capability of in situ continuous monitoring of total organic carbon in environmental water.