Bromine and chlorine determination in cigarette tobacco using microwave-induced combustion and inductively coupled plasma optical emission spectrometry

Abstract

A combustão iniciada com micro-ondas (MIC) foi aplicada para decomposição de amostras de tabaco de cigarro e subsequente determinação de bromo e cloro por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Massas de amostra de até 500 mg foram decompostas em frascos fechados e pressurizados com 20 bar de oxigênio. A combustão foi completada em menos de 30 s e os analitos foram absorvidos em solução diluída de (NH 4 ) 2 CO 3 . A exatidão foi avaliada usando materiais de referência certificados e mediante a determinação utilizando ICP-MS. A concordância foi melhor do que 98% usando 50 mmol L -1 de (NH 4 ) 2 CO 3 como solução absorvedora e 5 min de refluxo. A temperatura durante a combustão foi superior a 1400 °C e o conteúdo de carbono residual nos digeridos após MIC foi menor que 1%. Até oito amostras podem ser decompostas simultaneamente. Limites de quantificação utilizando MIC e determinação por ICP OES foram de 12 e 6 µg g -1 para Br e Cl, respectivamente.The microwave-induced combustion (MIC) was applied for cigarette tobacco samples digestion and further determination of bromine and chlorine by inductively coupled plasma optical emission spectrometry (ICP OES). Samples masses up to 500 mg were combusted in closed vessels using 20 bar of oxygen. Combustion was complete in less than 30 s and analytes were absorbed in diluted (NH 4 ) 2 CO 3 solution. Accuracy was evaluated using certified reference materials with similar matrix composition and comparison with results obtained using ICP-MS. The agreement was better than 98% using 50 mmol L -1 (NH 4 ) 2 CO 3 as absorbing solution and 5 min of reflux. Temperature during combustion was higher than 1400 °C and the residual carbon content in digest obtained after MIC was lower than 1%. Up to eight samples could be processed simultaneously and a single absorbing solution was suitable for both Br and Cl. Limit of quantification by MIC and further ICP OES determination was 12 and 6 µg g -1 for Br and Cl, respectively.Keywords: microwave-induced combustion, cigarette, bromine, chlorine, ICP OES IntroductionTobacco leaves may be used in different forms such as smoking, chewing or sniffing. All of these forms result in a number of negative side effects on human health that are well-documented.1 Chlorine and bromine are essential for growth of the plants and minor constituents of tobacco. The content of bromine and chlorine in tobacco could vary depending on tobacco type, soil and climatic conditions. Typical concentration ranges for Br and Cl reported in tobacco are 100 to 200 and 700 to 30000 µg g -1 , respectively. Over 85% of the all halogenated compounds found in tobacco and smoke are either halogenated agrochemicals, impurities found in the agrochemicals, or decomposition products from the agrochemicals. Up to 2.4% of the bromine and chlorine can be transferred to smoke. There are 242 identified halogenated compounds in tobacco and/or tobacco smoke and chlorine and bromine are present in 192 and 12 different compounds, respectively. 2Bromine...

Feasibility of ultra-trace determination of bromine and iodine in honey by ICP-MS using high sample mass in microwave-induced combustion

“…In this work, a microwave irradiation program was initially employed according to the conditions described in previous works [18,23,24]. In contrast to other studies in which complete combustion of a sample mass of 500 mg was achieved in about 30 to 50 s, in this study the combustion of 1000 mg of honey required up to 110 s. However, after about 70 s the absorbing solution already started to reflux, thereby wetting the sample and extinguishing the flame.…”

“…Microwave-induced combustion (MIC) has been successfully applied for the decomposition of organic samples for further determination of halogens owing to the high efficiency of matrix oxidation and the possibility of using alkaline solutions for analyte absorption [17][18][19][20][21][22][23][24][25][26][27]. In this method, solid samples are generally prepared as pellets and positioned on a quartz holder, and combustion is performed inside a quartz vessel pressurized with oxygen, using microwave radiation and ammonium nitrate solution for the ignition step.…”

Analytical methods for the determination of halogens in bioanalytical sciences: a review

“…A few microliters of ammonium nitrate is added to the filter paper to aid combustion [58,118]. MIC has been applied for many analytes and matrices such as food [58,111,120,121], botanical samples [83,86,122,123], soil [124], and petroleum-related matrices [125][126][127][128][129][130][131]. Dilute alkaline solutions are required to ensure quantitative recoveries for halogens when using MIC and to avoid losses, especially for bromine and iodine [58,91].…”

Determination of Bromide, Chloride, and Fluoride in Cigarette Tobacco by Ion Chromatography after Microwave-Induced Combustion

“…This procedure has been successfully applied for digestion of biological samples (Mesko et al 2010;Mü ller et al 2011;Pereira et al 2011), nanotubes (Pereira et al 2010), coal , and crude oil products (Pereira et al 2009) for further halogen determination.…”