Feasibility of microwave‐induced combustion combined with inductively coupled plasma mass spectrometry for bromine and iodine determination in human nail

Abstract

Rationale Bromine and iodine have important physiological functions; however, in inadequate concentration, they can also cause several physiological problems. Their mobility assessment in human organisms through biological sampling may help clarify some doubts related to metabolic routes, which are still not well elucidated. In this context, a suitable analytical method for this purpose should be developed. Methods An analytical method for determining ultratrace levels of bromine and iodine in human nail samples was developed. Inductively coupled plasma mass spectrometry (ICP‐MS) using a conventional nebulization system was immediately chosen as the determination tool because of its powerful sensitivity and selectivity. Sample preparation methods including microwave‐induced combustion (MIC), microwave‐assisted extraction, and microwave‐assisted digestion were evaluated. The compatibility of the final solutions with ICP‐MS analysis was considered while the method was developed. Results MIC was chosen as the most suitable method for the sample preparation for determining the levels of bromine and iodine in human nail samples using ICP‐MS. Unlike other sample preparation methods, this one fully eliminated interferences related to the carbon content and memory effects. Sample masses up to 100 mg were efficiently digested, and the analytes were quantitatively absorbed using only 50 mmol L−1 NH4OH solution. Recoveries ranged from 93% to 102%, and the relative standard deviation was < 8%. Conclusions The proposed analytical method presents important characteristics for routine analysis. It allows ultratrace determination even when low sample masses are used because of the low blank values, reduced volume of reagents, and powerful detectability using ICP‐MS.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…L-cysteine (pH ¼ 4.0), followed by ICP-MS analysis in no gas mode at mass 202 Hg. Total Hg was measured using a direct mercury analyser.…”

Laser ablation-ICP-mass spectrometry for determination of the concentrations and spatial distributions of bromine and iodine in human hair

“…However, these challenges can be effectively overcome using microwave-induced combustion (MIC) as a state-of-art approach for digestion of organic materials, in which the obtained solution is compatible with several analytical techniques. [18][19][20][21][22][23][24] Although originally intended for the determination of metals and metalloids, the high sensitivity, selectivity and multi-element capabilities of inductively coupled plasma-mass spectrometry (ICP-MS) also allow the quantication of non-metals. However, the high ionization energy of Br (11.81 eV) and of I (10.45 eV) is impeding their determination by ICP-MS. [18][19][20] Moreover, halogen determination using solutionbased pneumatic nebulization (PN-)ICP-MS is also impaired by the instability of some analyte species in solution, and by the potential occurrence of contamination and interference caused by the plasma gas, concomitant matrix components and reagents used during the sample preparation.…”