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Aerobic biodegradation of aliphatic polyethoxylates: An 1 H‐nuclear magnetic resonance spectroscopy investigation
Author(s) -
De Lazzari Alessandra,
Pojana Giulio,
Giacometti Andrea,
Lucchini Vittorio,
Marcomini Antonio
Publication year - 2002
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620210901
Subject(s) - biodegradation , chemistry , alkyl , nuclear magnetic resonance spectroscopy , depolymerization , mass spectrometry , spectroscopy , proton nmr , high performance liquid chromatography , chromatography , organic chemistry , physics , quantum mechanics
Aerobic biodegradation tests of three blends representative of the most commonly marketed aliphatic alcohol polyethoxylates (AE) and a commercial polyethylene glycols (PEG) mixture were run under standard test conditions (Organization for Economic Cooperation and Development, Paris, France [OECD] 301 E protocol). The test liquors were investigated using a 400‐MHz proton‐nuclear magnetic resonance ( 1 H‐NMR) spectrometer in order to elucidate the biodegradation mechanism. Diagnostic signals for both linear and branched AE homologs were identified by bidimensional homocorrelated spectroscopy (COSY) and by double quantum filter correlated spectroscopy (DQFCOSY). The 1 H‐NMR allowed individually monitoring the fate of the alkyl and polyethoxyl fragments of the parent compounds and distinguishing between oxidative and nonoxidative polyethoxyl depoly‐merization, which could not be performed by other reported techniques such as high‐peformance liquid chromatography (HPLC) or mass spectrometry (MS) or FAB spectroscopy. The AE biodegradation time profiles showed that under the test conditions, both alkyl and polyethoxyl chains of the linear and oxo ‐AE were biodegraded quite readily. The removal of the multibranched AE was slower when compared to that of linear and oxo ‐AE, while PEG exhibited a time profile characterized by a biodegradation rate significantly slower than that of PEG released by the microbial attack of linear and oxo ‐AE. In the case of linear AE, the alkyl chain was biodegraded much faster than the polyethoxyl chain, while in the case of oxo ‐ and multibranched AE, both the alkyl and the polyethoxyl chains were biodegraded at similar rates.