Analyte volatilization procedure for continuous-flow determination of bromine by atmospheric pressure helium microwave-induced plasma atomic emission spectrometry

Abstract

A simple method to generate a continuous flow of volatile bromine by oxidation of aqueous bromide is described for the determination of low concentrations of bromine by atmospheric pressure helium microwave-induced plasma atomic emission spectrometry. The bromine atom emission lines at 447.78 and 734.86 nm and the bromine ion emission line at 470.49 nm were selected as the analytical lines of interest. Of various oxidation reactions investigated, an oxidizing solution of 100 mmol dm-3 of potassium persulfate in 5.0 mol dm-3 sulfuric acid is the most appropriate for the generation of elemental bromine. The gaseous bromine is separated from the solution in a simple gas-liquid separator, dried with a desiccant of anhydrous calcium chloride and swept into the helium stream of a microwave-induced plasma for analysis. The best attainable detection limits (30 criterion) for bromine at 447.78, 470.49 and 734.86 nm were found to be 29.5, 7.46 and 18.4 ng ml-l, respectively, with corresponding background equivalent concentrations for bromine of 5.05, 1.72 and 2.42 pg ml-l. Typical analytical calibration graphs obtained under the optimized experimental conditions are rectilinear over approximately three orders of magnitude of concentration.

Dielectric barrier discharge-optical emission spectrometry for the simultaneous determination of halogens

“…39 Meanwhile, the higher ionization potential (24.6 eV) and metastable energy (19.73 or 20.53 eV) of helium provide a higher energy for halogen excitation. 40,41 In OES analysis, it is vital to select an appropriate characteristic emission line with high detection sensitivity and low spectral interference for quantication. The most sensitive resonance emission lines of halogens located in the vacuum ultra-violet spectral region were selected in conventional ICP-OES analysis, e.g., Cl 134.724 and 135.165 nm, Br 148.845, 153.174 and 154.065 nm, and I 142.549, 178.276 and 183.038 nm.…”

Development of Gas-Phase Sample-Introduction Techniques for Analytical Atomic Spectrometry

“…Such a newly-fabricated instrumentation of MIP-AES coupled with the analyte volatilization reaction has been successfully applied to the determination of iodine in seawater and brine samples with a DL of 2.3 ng/ml at 183.0 nm, 70,71,[73][74][75] bromine in seawater with a DL of 7.46 ng/ml at 470.4 nm [75][76][77] and chlorine in water samples with a DL of 6.8 ng/ml at 479.5 nm. 78 Moreover, the selective determination of iodide and iodate in brine water samples as an inorganic speciation of iodine has been carried out.…”

Total organochloride and organobromide determinations in aqueous samples by microwave induced plasma-optical emission spectrometry

“…However, the limited thermal energy available in the commonly used low-power MIPs restricts the use of these plasmas to gas phase sample introduction. Previous experiments have shown that the determination of inorganic chloride and bromide in water samples by on-line chemical oxidation to the corresponding volatile halogen with KMnO4 in acid media and final detection by MIP-OES can be successfully accomplished using a Beenakker cavity for plasma generation [7][8][9].In our search for improved analytical approaches of the conventional AOX method, alternatives to the incineration and microcoulometric detection steps have been investigated in this work. The outline of the basic approach followed here is shown in Fig.…”