Fatty Alcohols: Anthropogenic and Natural Occurrence in the Environment

174 Pages·2008·27.45 MB·English

by  Stephen Mudge

Fatty Alcohols
Anthropogenic and Natural Occurrence in the Environment

Fatty Alcohols
Anthropogenic and Natural Occurrence
in the Environment
Stephen M Mudge
School of Ocean Sciences, Bangor University, UK
Scott E Belanger
Central Product Safety, Procter & Gamble, USA
Allen M Nielsen
SASOL-North America, USA
ISBN: 978-0-85404-152-7
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AISEandCESIO)andSDA
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Preface
Fatty alcohols are widespread in the environment coming from a range of nat-
ural sources including bacteria, plants and animals. These compounds are also
manufactured by industry from natural fatty acid sources or from petroleum-
derived carbon. This book presents their environmental occurrence, fate and
behaviour. The principal focus of past research has been on their natural pro-
duction,which occurs inall living organismsfrom bacteria tohumans, andthe
profiles and concentrations of these compounds in water, soils and sediments.
Theirrelativelynon-polarnaturemeanstheyareprincipallyassociatedwithsolid
phases in aquatic systems (e.g. sediments) rather than dissolved in water. The
majorbiologicalsyntheticpathwayisfromthereductionoffattyacids,through
aldehyde intermediates, to fatty alcohols and in many organisms to esters with
fatty acids to form waxes. These waxes are used by organisms for a variety of
purposes, from the prevention of desiccation in the terrestrial environment to
energy reserves in the marine environment. They are ubiquitous and occur in
mostenvironmentsaroundtheworld,includingthedeepoceanandinsediment
cores.
Due to the nature of the synthetic pathway using acetyl-CoA, most fatty
alcoholsareofanevenchainlength.Terrestrialplantsutilisefattyalcoholsasa
waxycoating,dominatedbylongchainmoietieswithchainlengthsfromC to
22
C . In contrast, marine organisms synthesise smaller compounds with peak
32
chain lengths ofC to C . Bacteria also produce fatty alcoholsbut these can
14 16
alsobeoddchainlengthsandcontainbranches.Thisaspectoftheiroccurrence
enables them to be used as biomarkers for organic matter sources. As well as
their natural production and occurrence, fatty alcohols are also utilised in
detergent formulations, principally as sulfates or polyethoxylates.
The analytical method preferred by contemporary environmental scientists
used to measure the concentration of the ethoxylates involves direct derivati-
sation with a pyridinium complex and quantification via LC-MS (liquid
chromatography–mass spectrometry). This technique will detect free fatty
FattyAlcohols:AnthropogenicandNaturalOccurrenceintheEnvironment
ByStephenMMudge,ScottEBelanger,andAllenMNielsen
rCopyright2008ERASM(thejointsurfactantenvironmentalresearchplatformofAISEandCESIO)andSDA
PublishedbytheRoyalSocietyofChemistry,www.rsc.org
v
vi Preface
alcoholsaswellastheethoxylates,butwillnotdetectanyoftheboundalcohols
suchasthewaxes.Todetectthislattergroup,asaponificationstepisrequired.
This second method, frequently using GC-MS (gas chromatography–mass
spectrometry), in combination with the LC method will detect all of the
ethoxylates and may be considered as givinga good measure ofthe total fatty
alcohols present in a system.
The concentration of individual fatty alcohols in the environment ranges
from low values in old deep cores and the open ocean floor (undetectable to
12ngg(cid:1)1 dry weight (DW) for C ) to high values near natural sources and
16
especiallyinsuspendedparticulatematter(2.7(cid:2)106ngg(cid:1)1DWforC );thisis
16
almost a factor of 106 difference in their concentrations. The short chain
compoundsaremorereadilydegradablethanthelongerchaincompoundsand,
in many cases, are removed first as a preferred food source for bacteria. The
longerchaincompoundsmayalsodegradetoshortchaincompoundswithtime
but, in general, the 4C class of alcohols degrades more slowly in sediments
20
and soils than the oC class.
20
The different compound profiles for each source has made them suitable as
biomarkers and the use of multivariate statistical methods can clearly distin-
guish compounds from each potential source as well as sites. Principal com-
ponent analysis (PCA) is particularly useful in this regard. Signature analysis
using partial least squares (PLS) analysis has been used successfully to dis-
criminate between samples that are impacted by marine versus terrestrial
sources. However, due to the commonality of fatty alcohol detergent for-
mulations and the natural environmental alcohols, source partitioning on the
basis of compounds alone is not as successful. When ascribing proportions to
such sources, a different approach such as stable isotopes may be more
appropriate.
Based on the toxicity and ecotoxicity testing of fatty alcohols, they are
relativelybenignintheenvironmentduetolowenvironmentalexposures.Free
fatty alcohols have been shown to undergo very rapid and complete biode-
gradation. Fatty alcohols lack effects on genotoxicity and reproductive and
developmental toxicity, and carcinogenicity. Health studies for oral, ingestion
and inhalation exposure have all shown good margins of safety for human
health and are, therefore, unlikely to lead to effects on the aquatic ecosystem.
Contents
Acknowledgements xii
About the Authors xiii
Chapter 1 Definitions
1.1 Names and Structures 1
1.2 Physicochemical Properties 3
1.2.1 Solubility Versus Chain Length 3
1.2.2 Partitioning (K ) and Sediment Associations 6
ow
Summary 9
Chapter 2 Biological Synthesis
2.1 Type I Fatty Acid Synthesis 10
2.1.1 Unsaturated Chains 12
2.2 Type II Fatty Acid Synthesis 14
2.2.1 Unsaturated Compounds 14
2.2.2 Branched Chains 15
2.3 Fatty Acid Degradation 15
2.4 Fatty Acyl-CoA Reductase (FAR) 15
2.5 Synthesis From Carbohydrates (Copepods) 18
Summary 19
Chapter 3 Occurrence in Biota
3.1 Bacteria 21
3.2 Chlorophyll Side Chain (Phytol) 21
3.3 Marine Plants 23
3.4 Terrestrial Plant Waxes 24
FattyAlcohols:AnthropogenicandNaturalOccurrenceintheEnvironment
ByStephenMMudge,ScottEBelanger,andAllenMNielsen
rCopyright2008ERASM(thejointsurfactantenvironmentalresearchplatformofAISEandCESIO)andSDA
PublishedbytheRoyalSocietyofChemistry,www.rsc.org
vii
viii Contents
3.5 Mosses and Other Peat-Forming Plants 25
3.6 Marine Animals 25
3.7 Insects 28
3.8 Birds 30
Summary 31
Chapter 4 Consumer and Cosmetic Product Uses and Production
4.1 Detergent Alcohols Manufacture 33
4.1.1 Oleochemical-based Alcohols 33
4.1.2 Oleochemical Fatty Alcohols 35
4.2 Petrochemical-based Alcohols 36
4.2.1 Internal Olefins 36
4.2.2 Conventional OXO Alcohols Based
on Internal Olefins 37
4.3 Alcohols Based on Ethylene 38
4.3.1 Ziegler Ethylene Growth Process 38
4.3.2 Ziegler Alcohols 38
4.4 Modified OXO Alcohols 39
4.4.1 SHOP (Shell Higher Olefin Process)
a-Olefins 39
4.4.2 SHOP Internal Olefins and Modified
OXO Alcohols 39
4.5 Summary of Products 41
4.6 Detergent Formulations 41
4.6.1 Japan 47
4.6.2 Western Europe 48
4.6.3 North America 49
4.7 Future Fatty Alcohol Production 49
Summary 51
Chapter 5 Environmental Transformations
5.1 Metabolism of Fatty Alcohols 52
5.2 Natural Degradation 55
5.2.1 Short Chain Moieties 55
5.2.2 Long Chain Moieties 59
5.3 Degradation Rate Constants 60
5.3.1 Phytol Degradation 62
5.4 Effect of Chemical Associations
on Transformation Rates 63
5.4.1 ‘‘Natural’’ Fatty Alcohols in STPs 63
5.4.2 Anthropogenic Fatty Alcohols in STPs 64
5.4.3 Sources of Fatty Alcohols in the Environment 65
Summary 66
Contents ix
Chapter 6 Analytical Methods
6.1 Overview of Methods 67
6.2 Methods for Analysis of Free Fatty Alcohols
(and Ethoxylates) 67
6.3 Environmental Samples 69
6.4 Inter-laboratory Comparisons 71
Summary 74
Chapter 7 Environmental Concentrations
7.1 The Marine Environment 76
7.1.1 Victoria Harbour, BC, Canada: Estuarine
Surface Sediments (A) 76
7.1.2 Concepcio´nBay,Chile(B1);SanVicenteBay,
Chile (B2) 79
7.1.3 Rio de Janeiro: Surface Sediments
in a Contaminated Bay (C) 82
7.1.4 RiaFormosaLagoon:SurfaceSediments(D1) 83
7.1.5 RiaFormosaLagoon:SuspendedandSettled
Sediments (D2) 86
7.1.6 Ria Formosa Lagoon: Shallow Core from
Intertidal Sediments (D3) 87
7.1.7 Eastern North Atlantic (E) 88
7.1.8 San Miguel Gap, California: Long Marine
Core (F) 89
7.1.9 Rio Grande Rise (516F of Leg 72 ODP),
Brazil (G) 89
7.1.10 Falkland Plateau (511 of Leg 71 ODP),
South Atlantic (H) 92
7.1.11 Guatemalan Basin (Legs 66 and 67 ODP),
Central America (I) 92
7.1.12 Continental Slope, Southwest of Taiwan (J1) 92
7.1.13 East China Sea, North of Taiwan (J2) 94
7.2 The Terrestrial Environment 95
7.2.1 Pasture Land, Southern Australia (K) 95
7.2.2 Prairie Zone Soils, Alberta, Canada (L) 95
7.3 UK Studies 96
7.3.1 Conwy Estuary: Estuarine Core (50cm) (1) 97
7.3.2 Mawddach Estuary: Surface Sediments (2) 99
7.3.3 Menai Strait: Surface Sediments (3) 99
7.3.4 Loch Riddon, Scotland: Mid-length Marine
Core (4) 101
7.3.5 Clyde Sea, Scotland: Surface Sediments (5) 102
7.3.6 Looe Pool, Cornwall: Coastal Lake (6) 105
7.3.7 Bolton Fell Moss, Cumbria: Mire (7) 105