Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry

We developed a selective technique to rapidly measure free chlorine, which is the sum of elemental chlorine (Cl<sub>2</sub>), hypochlorous acid (HOCl), and hypochlorite (OCl<sup>−</sup>) in water samples via an electrophilic aromatic substitution reaction hyphenated with liqu...

Full description

Saved in:
Bibliographic Details
Main Authors: Avital Shifrovitch, Moran Madmon, Tamar Shamai Yamin, Avi Weissberg
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Organics
Subjects:
Online Access:https://www.mdpi.com/2673-401X/5/4/32
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850239465266610176
author Avital Shifrovitch
Moran Madmon
Tamar Shamai Yamin
Avi Weissberg
author_facet Avital Shifrovitch
Moran Madmon
Tamar Shamai Yamin
Avi Weissberg
author_sort Avital Shifrovitch
collection DOAJ
description We developed a selective technique to rapidly measure free chlorine, which is the sum of elemental chlorine (Cl<sub>2</sub>), hypochlorous acid (HOCl), and hypochlorite (OCl<sup>−</sup>) in water samples via an electrophilic aromatic substitution reaction hyphenated with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Sample preparation involved derivatization at 25 °C for 15 min with 3,4,5-trimethoxyphenylacetic acid (TMPAA) in an aqueous solution prior to analysis. Several parameters were evaluated to determine the optimized reaction and for the production of informative MS/MS spectrum of the derivatization product, 2-chloro-3,4,5-trimethoxyphenylacetic acid (Cl-TMPAA). The resulting Cl-TMPAA derivative displayed an informative ESI-MS/MS spectrum characterized by product ions at <i>m</i>/<i>z</i> 232.0142, 200.0245, and 185.0009 from the precursor ion at <i>m</i>/<i>z</i> 259.0379. The linear dynamic range of the method (0.1–10 µg/mL) was fitted to concentration levels relevant to forensic toxicology issues. Compared with other analytical techniques, this newly established LC-MS-based method demonstrated specificity, simplicity, and rapidity. This method enables the detection of free chlorine for forensic investigations in criminal cases.
format Article
id doaj-art-e298fb2aac98403dbf7c0a2ca80711d1
institution OA Journals
issn 2673-401X
language English
publishDate 2024-12-01
publisher MDPI AG
record_format Article
series Organics
spelling doaj-art-e298fb2aac98403dbf7c0a2ca80711d12025-08-20T02:01:09ZengMDPI AGOrganics2673-401X2024-12-015461462210.3390/org5040032Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass SpectrometryAvital Shifrovitch0Moran Madmon1Tamar Shamai Yamin2Avi Weissberg3Department of Analytical Chemistry, Israel Institute for Biological Research (IIBR), Ness Ziona 7410001, IsraelDepartment of Analytical Chemistry, Israel Institute for Biological Research (IIBR), Ness Ziona 7410001, IsraelDepartment of Analytical Chemistry, Israel Institute for Biological Research (IIBR), Ness Ziona 7410001, IsraelDepartment of Analytical Chemistry, Israel Institute for Biological Research (IIBR), Ness Ziona 7410001, IsraelWe developed a selective technique to rapidly measure free chlorine, which is the sum of elemental chlorine (Cl<sub>2</sub>), hypochlorous acid (HOCl), and hypochlorite (OCl<sup>−</sup>) in water samples via an electrophilic aromatic substitution reaction hyphenated with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Sample preparation involved derivatization at 25 °C for 15 min with 3,4,5-trimethoxyphenylacetic acid (TMPAA) in an aqueous solution prior to analysis. Several parameters were evaluated to determine the optimized reaction and for the production of informative MS/MS spectrum of the derivatization product, 2-chloro-3,4,5-trimethoxyphenylacetic acid (Cl-TMPAA). The resulting Cl-TMPAA derivative displayed an informative ESI-MS/MS spectrum characterized by product ions at <i>m</i>/<i>z</i> 232.0142, 200.0245, and 185.0009 from the precursor ion at <i>m</i>/<i>z</i> 259.0379. The linear dynamic range of the method (0.1–10 µg/mL) was fitted to concentration levels relevant to forensic toxicology issues. Compared with other analytical techniques, this newly established LC-MS-based method demonstrated specificity, simplicity, and rapidity. This method enables the detection of free chlorine for forensic investigations in criminal cases.https://www.mdpi.com/2673-401X/5/4/32free chlorineaqueous mediaderivatizationelectrophilic aromatic substitutionLC-ESI-MS/MS
spellingShingle Avital Shifrovitch
Moran Madmon
Tamar Shamai Yamin
Avi Weissberg
Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
Organics
free chlorine
aqueous media
derivatization
electrophilic aromatic substitution
LC-ESI-MS/MS
title Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
title_full Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
title_fullStr Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
title_full_unstemmed Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
title_short Simple and Selective Determination of Free Chlorine in Aqueous Solutions by an Electrophilic Aromatic Substitution Reaction Followed by Liquid Chromatography Coupled with Mass Spectrometry
title_sort simple and selective determination of free chlorine in aqueous solutions by an electrophilic aromatic substitution reaction followed by liquid chromatography coupled with mass spectrometry
topic free chlorine
aqueous media
derivatization
electrophilic aromatic substitution
LC-ESI-MS/MS
url https://www.mdpi.com/2673-401X/5/4/32
work_keys_str_mv AT avitalshifrovitch simpleandselectivedeterminationoffreechlorineinaqueoussolutionsbyanelectrophilicaromaticsubstitutionreactionfollowedbyliquidchromatographycoupledwithmassspectrometry
AT moranmadmon simpleandselectivedeterminationoffreechlorineinaqueoussolutionsbyanelectrophilicaromaticsubstitutionreactionfollowedbyliquidchromatographycoupledwithmassspectrometry
AT tamarshamaiyamin simpleandselectivedeterminationoffreechlorineinaqueoussolutionsbyanelectrophilicaromaticsubstitutionreactionfollowedbyliquidchromatographycoupledwithmassspectrometry
AT aviweissberg simpleandselectivedeterminationoffreechlorineinaqueoussolutionsbyanelectrophilicaromaticsubstitutionreactionfollowedbyliquidchromatographycoupledwithmassspectrometry