Simultaneous Determination Of Bromine Research Articles

Simultaneous determination of bromine and iodine in milk powder for adult and infant nutrition by plasma based techniques after digestion using microwave-induced combustion

In this work, bromine and iodine determination in milk powder for adult and infant nutrition was performed by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) after digestion by microwave-induced combustion (MIC). Contrarily to previous works using MIC, a higher sample mass was digested (700 mg). Water and ammonium hydroxide (10 to 100mmolL−1) were investigated as absorbing solutions and accurate results were achieved using a 25mmolL−1 NH4OH solution. Moreover, the high stability of analytes after digestion (up to 30 days) using this solution was observed. The accuracy of the proposed MIC method was evaluated using certified and reference materials of milk powder (NIST 1549 and NIST 8435). No statistical difference was observed between results obtained by MIC-ICP-MS and reference values. Results for samples were also compared with those obtained by ICP-OES and no statistical difference was observed. Microwave-assisted alkaline extraction (MW-AE) was also evaluated for milk powder using NH4OH and tetramethylammonium hydroxide solutions. Solutions obtained after digestion by MIC (whole milk powder) presented low carbon content in digests (<25mgL−1) while solutions obtained after alkaline extraction presented up to 10,000mgL−1 of C. MIC method was preferable in view of the possibility of obtaining solutions with low carbon content even using a relatively high sample mass (up to 700mg) avoiding additional dilution prior to ICP-MS analysis, thus allowing better detection limits. Limits of detection obtained by MIC-ICP-MS were 0.007 and 0.003μgg−1 for Br and I, respectively, while for MW-AE were 0.1 and 0.05μgg−1 respectively for Br and I. Among the main advantages of the proposed method are the use of diluted alkaline solutions that is in agreement with green analytical chemistry recommendations, the high stability of analytes in solution and the suitability of digests for analysis by ICP-MS and also ICP-OES, minimizing memory effects and being advantageous for routine analysis.

Simultaneous determination of bromine and chlorine in coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis

A new method for the direct analysis of coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis was developed, aiming at the determination of Br and Cl. The procedure does not require any significant sample pretreatment and allows simultaneous determination of both elements to be carried out, requiring small mass aliquots of sample (about 0.5mg). All operating parameters, including carrier gas flow-rate and RF power, were optimized for maximum sensitivity. The use of modifiers/aerosol carriers (Pd, Pd+Al and Pd+Ca) was evaluated, and the mixture of Pd and Ca was chosen, allowing pyrolysis and vaporization temperatures of 700°C and 1900°C, respectively. Chlorine was accurately determined using calibration against solid standards, whereas Br could also be determined using calibration against aqueous standard solutions. The limits of quantification were 0.03μgg−1 for Br and 7μgg−1 for Cl, and no spectral interferences were observed.

Halogen speciation in the rat thyroid: Simultaneous determination of bromine and iodine by short-term INAA

The study describes a mode of non-destructive simultaneous determination of bromine and iodine concentrations, by reactor instrumental neutron activation analysis (INAA) in the regime of short-term activation. Under the conditions of 1-minute activation in the neutron flux of 8.0·1013 n·cm−2·s−1, it was possible to determine reliably as little as 5·10−8 g bromine and about 10−7 g iodine in matrices of a given type and of the mass of about 5 mg dry weight. We applied this method for the determination of Br and I concentrations in the whole rat thyroid gland as well as for the halogen speciation in fractions separated from this organ.

Simultaneous determination of bromine and chlorine in cow's milk by radioactivation analysis.

Bromine and chlorine have been determined in cow's milk by radioactivation analysis. These elements are adsorbed from irradiated samples on to silver hexacyanoferrate(II) Amberlite IRA 904 resin. The recovery from this resin is about 96% for both elements. The limit of detection is about 5 µg for bromine and about 1 mg for chlorine using a Van der Graaf accelerator and about 50 µg for bromine and 2 mg for chlorine using the Kinki University research reactor (thermal neutron flux of 1.5 × 107 n cm–2 s–1).The precision of the method is about ±10% for bromine and about ±20% for chlorine for concentrations exceeding 5 p.p.m.