Challenges and trends for halogen determination by inductively coupled plasma mass spectrometry: A review

Abstract

Rationale In this review, works published in the past 25 years for fluorine, chlorine, bromine, and iodine determination in several matrices by inductively coupled plasma mass spectrometry (ICP‐MS) were covered. Usually, the determination of halogens has been performed by ICP‐MS using a previous sample preparation step or, more recently, by direct analysis of solid or liquid samples. Methods Methods based on combustion, extraction, pyrohydrolysis, sample dilution in organic or aqueous medium, and wet digestion, among others, are discussed. Moreover, the recent applications of methods based on laser ablation (LA) and electrothermal vaporization (ETV) coupled to ICP‐MS are discussed. Results The main challenge for methods using sample preparation has been to obtain a final solution compatible with ICP‐MS, as well as to overcome problems related to analyte losses and contamination. Interferences due to the presence of dissolved organic compounds in solution, enhancement or suppression of ionization of analytes, and related matrix effects have been of concern when using ICP‐MS. For the determination of halogens by ICP‐MS using LA and ETV systems, some limitations related to the difficulty of calibration are pointed out, impairing the widespread use of this approach. Conclusions A critical view is presented for further halogen determination by ICP‐MS, mainly for matrices considered difficult to digest using conventional protocols.

Mass Spectrometry‐based Techniques for Direct Quantification of High Ionization Energy Elements in Solid Materials—challenges and Perspectives

“…For the comprehensive review concerning the use of ICP‐MS and other techniques for the quantification of chlorine, bromine, and iodine, the reader is referred to the recent review by Tjabadi and Mketo (2019). Also recently, Flores et al (2020) reviewed the application of ICP‐MS for halogens quantification.…”

Trends towards Effective Analysis of Fluorinated Compounds Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

“…This method was used to determine F in blood serum, where ether was used as an extract followed by perchloric acid [ 62 ]. It is more efficient compared with other methods such as open ashing-fluoride electrode, oxygen-bomb fluorine electrode, and oxygen-bomb gas chromatography in terms of F loss and contamination with extraneous F. The challenge of using this method is the fact that it releases volatile compounds such as HF which causes nonquantitative recoveries [ 63 , 64 ]. Therefore, the wet digestion method for FCs sample preparation requires novel ways to control the production of HF.…”

“…Decomposition methods of combustion and pyrohydrolysis [ 63 , 65 ] use a concentrated solution [ 66 ]. Combustion methods that are used to prepare FCs samples include dry ashing [ 11 , 67 , 68 ], combustion bomb [ 66 , 69 – 71 ], Wick-bold apparatus [ 72 ], Schoniger flask [ 73 ], and microwave-induced combustion [ 74 – 76 ].…”

“…The main interferences encountered during quadrupole-ICP-MS (ICP-QMS) application for analysis of FCs are isobaric, doubly charged, and polyatomic [ 63 ]. Isobaric interferences occur when signals of different ionic species with the same m/z ratio overlap.…”

“…The formation of molecules in the plasma results in polyatomic interference [ 63 ]. This is when Ar reacts with elements such as hydrogen (H), nitrogen (N), and oxygen (O) amongst others originating from acids dissolving the samples.…”