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

Abstract

Fluorine, chlorine, bromine, and iodine have been studied in biological samples and other related matrices owing to the need to understand the biochemical effects in living organisms. In this review, the works published in last 20 years are covered, and the main topics related to sample preparation methods and analytical techniques commonly used for fluorine, chlorine, bromine, and iodine determination in biological samples, food, drugs, and plants used as food or with medical applications are discussed. The commonest sample preparation methods, as extraction and decomposition using combustion and pyrohydrolysis, are reviewed, as well as spectrometric and electroanalytical techniques, spectrophotometry, total reflection X-ray fluorescence, neutron activation analysis, and separation systems using chromatography and electrophoresis. On this aspect, the main analytical challenges and drawbacks are highlighted. A discussion related to the availability of certified reference materials for evaluation of accuracy is also included, as well as a discussion of the official methods used as references for the determination of halogens in the samples covered in this review.

Study on pathway and characteristics of ion secretion of salt glands of Limonium bicolor

“…were analyzed by the Dionex ICS-1100 ion chromatography system (Dionex Corp., Sunnyvale, CA, USA). The Cl -anion was determined according to the spectrophotometric method (gelatin-alcohol water solution as protective colloid) (Mello et al 2013).…”

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

“…The determination of halogens has been performed by inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP OES), and ion chromatography (IC) [15,16]. In particular, ICP-MS presents high selectivity and suitable LODs for Br and I determination in low concentrations [16].…”

Evaluation of bromine and iodine content of milk whey proteins combining digestion by microwave-induced combustion and ICP-MS determination

“…Moreover, the high acidity of digests could cause interferences on the determination by ICP-MS and a dilution or neutralization of digests is often required (Todoli & Mermet, 1999). In this way, alkaline media (e.g., KOH, TMAH, CFA-C) could be used to minimize losses, but in general these procedures provide only a dissolution of the sample and so interferences of the organic matrix that remains in digests are expected in ICP-MS determination (Mello et al, 2013;Sullivan & Zywicki, 2012).…”

“…The lack of information about the content of Br and I in whey proteins could be explained at least partially by the analytical challenges related to their determination at low concentration (Mello et al, 2013). In this way, several techniques such as ion chromatography, potentiometry with ion-selective electrodes, inductively coupled plasma optical emission spectrometry, and graphite furnace molecular absorption spectrometry present limitations due to the unsuitable limit of detection (LOD) for the determination of Br and I in whey proteins.…”