Application of the novel 5-chloro-2,2,3,3,4,4,5,5-octafluoro-1-pentyl chloroformate derivatizing agent for the direct determination of highly polar water disinfection byproducts |
| |
Authors: | Marco Vincenti Francesca Fasano Maria Carmen Valsania Pierantonio Guarda Susan D Richardson |
| |
Institution: | 1. Dipartimento di Chimica Analitica, Università degli Studi di Torino, Via Pietro Giuria 5, 10125, Torino, Italy 2. Dipartimento di Traumatologia, Ortopedia e Medicina del Lavoro, Università degli Studi di Torino, Via Zuretti 29, 10126, Torino, Italy 3. Solvay Solexis S.p.A., Viale Lombardia, 20, Bollate, 20021, Milan, Italy 4. National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens, GA, 30605, USA
|
| |
Abstract: | A novel derivatizing agent, 5-chloro-2,2,3,3,4,4,5,5-octafluoropentyl chloroformate (ClOFPCF), was synthesized and tested
as a reagent for direct water derivatization of highly polar and hydrophilic analytes. Its analytical performance satisfactorily
compared to a perfluorinated chloroformate previously described, namely 2,2,3,3,4,4,5,5-octafluoropentyl chloroformate (OFPCF).
The chemical properties (reactivity, selectivity, derivatization products, and their chromatographic and spectral features)
for ClOFPCF were investigated using a set of 39 highly polar standard analytes, including, among others, hydroxylamine, malic
and succinic acids, resorcinol, hydroxybenzaldehyde, and dihydroxybenzoic acid. Upon derivatization, the analytes were extracted
from the aqueous solvent and analyzed by gas chromatography (GC)-mass spectrometry (MS) in the electron-capture negative ionization
(ECNI) mode. Positive chemical ionization (PCI)-MS was used for confirming the molecular ions, which were virtually absent
in the ECNI mass spectra. ClOFPCF showed good reaction efficiency, good chromatographic and spectroscopic properties (better
than with OFPCF), good linearity in calibration curves, and low detection limits (0.3–1 μg/L). A unique feature of the derivatizations
with ClOFPCF, and, in general, highly fluorinated chloroformates, is their effectiveness in reacting with carboxylic, hydroxylic,
and aminic groups at once, forming multiply-substituted non-polar derivatives that can be easily extracted from the aqueous
phase and determined by GC-ECNI-MS. The entire procedure from raw aqueous sample to ready-to-inject hexane solution of the
derivatives requires less than 10 min. Another benefit of this procedure is that it produced stable derivatives, with optimal
volatility for GC separation, and high electron affinity, which allows their detection as negative ions at trace level. In
addition, their mass spectra exhibits chlorine isotopic patterns that clearly indicate how many polar hydrogens of the analyte
undergo derivatization. Finally, derivatization with ClOFPCF was used successfully to identify 13 unknown highly polar disinfection
byproducts (DBPs) in ozonated fulvic and humic acid aqueous solutions and in real ozonated drinking water. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|