Studies of aliphatic amines and other volatile organic compounds in the marine environment.

Kamil. Abdul-Rachid, Mohamed (1990) Studies of aliphatic amines and other volatile organic compounds in the marine environment. PhD thesis, University of Liverpool.

Text 316561.pdf - Unspecified Download (86MB) | Preview

Abstract

PART ONE. A highly sensitive and reproducible method for the determination of aliphatic amines namely monomethylamine (MMA), dimethylamine (DMA) , and trimethylamine (TMA) in marine environmental samples (water and sediments) has been developed. This involves an initial stage in which the amines are preconcentrated by microdiffusion and subsequently determined using a gas chromatograph equipped with a packed column and Nitrogen Phosphorus Selective Detector (NPSD) . The detection limit is at sub ppb level (ng/l), and the method recoveries are in the ranges of 58-68% for MMA, 55-84.3% for DMA, and 83-105.5% for TMA for the range of concentrations between 2-40 ppb. The percentage standard deviations of the chromatographic measurements are <15.1% for MMA, <11.1% for DMA, and <10% for TMA. The untreated Chromosorb 103 column packing was found to be very stable for more than a year with little deterioration in performance. Using this method, the production of methylamines by a marine phytoplankton has been studied, and has been shown to be greatly influenced by the growth conditions i.e bacteriostatic and nonbacteriostatic culture media, different levels and types of N sources, and zooplankton grazing on the phytoplankton. Maximum concentrations of methylamines were observed in the N03- enriched bacteriostatic medium. Zooplankton grazing also increases their levels. Methylamines were found to be distributed in a range of marine environments, with highest concentrations detected in marine sediments. Their levels were also higher in polluted Mersey waters than in the water off the Isle of Man (10M). MMA was found to be the dominant species in all of these samples (phytoplankton, sediment, and water) and also in the marine atmosphere. Using the same approach, l-Arninopropan-2-one, which has long been known to be a compound of urine, has been shown to be a stable indicator of raw sewage pollution. Its identity has been confirmed by GC-MS of its trifluoro acyl-derivative. Its distribution in estuarine water (Mersey Estuary) and coastal water (Port Erin, 10M) is presented. PART TWO. Volatile organic compounds (VOCs) in phytoplankton cultures, marine sediments, and Mersey Estuary water samples have been determined by a modified Grob closed-loop stripping method and GC-MS analysis. VOCs in the Mersey estuary water samples were dominated by methylated benzenes and methylated naphthalenes. In contrast, chlorinated compounds were the dominant compounds in the sediments, and methylated alkanes in the non-bacteriostatic phytoplankton culture. Some methylated benzenes were also found in the plankton sample, which might explain their observation in some of the remote unpolluted marine environment. This thesis is dedicated to my parents, my wife and children.

Item Type:	Thesis (PhD)
Depositing User:	Symplectic Admin
Date Deposited:	23 Oct 2023 09:57
Last Modified:	23 Oct 2023 10:00
DOI:	10.17638/03175918
Copyright Statement:	Copyright © and Moral Rights for this thesis and any accompanying data (where applicable) are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge.
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3175918