Development of a passive, in situ, integrative sampler for monitoring biotoxins in aquatic ...

219 Pages·2015·4.96 MB·English

COPYRIGHT AND CITATION CONSIDERATIONS FOR THIS THESIS/ DISSERTATION

Attribution — You must give appropriate credit, provide a link to the license, and indicate if
o
changes were made. You may do so in any reasonable manner, but not in any way that
suggests the licensor endorses you or your use.

NonCommercial — You may not use the material for commercial purposes.
o

ShareAlike — If you remix, transform, or build upon the material, you must distribute your
o
contributions under the same license as the original.

How to cite this thesis
Surname, Initial(s). (2012) Title of the thesis or dissertation. PhD. (Chemistry)/ M.Sc. (Physics)/
M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved
from: https://ujdigispace.uj.ac.za (Accessed: Date).
Development of a Passive, in situ, Integrative Sampler
for Monitoring Biotoxins in Aquatic Environments

Hlengilizwe Nyoni

A thesis submitted to the Faculty of Science, University of Johannesburg, in
fulfilment of the requirements for the Doctoral degree in Science (Chemistry)

Supervisor:
Prof Titus A.M. Msagati

Co-supervisor:
Prof Bhekie B. Mamba

University of Johannesburg, September 2015
ABSTRACT

This thesis focuses on functionalising the silicone membrane by filling it with
synthesised γ-Fe O nanoparticles for the purpose of using it as a passive sampling
2 3
device for monitoring microcystins and cylindrospermopsin in aquatic environments.
The identity and purity of the synthesised nanoparticles was verified by X-ray diffraction
(XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM),
surface zeta potential analyser and Brunauer-Emmet-Teller (BET).

There was no chemical uptake of microcystin compounds into the silicone membrane
without a suspension of maghemite nanoparticles. But, a linear uptake of microcystin
compounds was observed into the functionalised silicone membrane passive sampler
throughout the exposure period. These findings suggest that the silicone membrane

filled with a suspension of synthesised γ-Fe O nanoparticles can be an efficient, green
2 3
and less costly instrument useful in estimating biotoxin concentrations in South African
waters and the world at large.

This novel device was calibrated for the measurement of microcystin and
cylindrospermopsin concentrations in water. The effect of temperature and
hydrodynamics on the sampler performance was studied in a flow-through system

ii
ABSTRACT
under controlled conditions. The chemical uptake of microcystins (MCs) and
cylindrospermopsin (CYN) into the passive sampler remained linear and integrative

ii
ABSTRACT

throughout the 28 days exposure. The rate of accumulation of most of the MC
compounds tested was dependent on temperature and flow velocity. The use of
performance reference compounds (PAHs and 13C labelled polychlorinated biphenyls)
spiked into the newly developed silicone membrane / γ-Fe O nanoparticle passive
2 3
sampler, Chemcatcher and POCIS improved the semi quantitative nature of water
concentration estimates in natural water. The corrected sampling rate values of model
biotoxin compounds were used for calculations of time-weighted average
concentrations in natural water.

Further, a field study to test the newly developed sampler’s performance alongside
commercially available Chemcatcher (polar version), Polar organic chemical integrative
sampler (pharmaceutical configuration) and solid phase extraction technique (grab

sampling) was conducted. The developed novel sampling device was employed for the

measurement of time-weighted average concentrations of cylindrospermopsin (CYN)
and microcystins (MCs) in natural cyanobacterial water blooms of the Hartbeespoort
dam. Data obtained by the three passive sampling devises provided a more relevant
picture of the situation and enabled better assessment of potential risks. The results
suggested that the three sampling devices are suitable for use in monitoring microcystin
and cylindrospermopsin concentrations in aquatic environments.

iii
DEDICATION

This thesis is dedicated to my wife, Nonhlanhla Mediatrix Nyoni and my daughter,
Ilomsa Nicole Nyoni, for their understanding, inspiration, and faithfulness in reminding
me that they are my number one team.

iv
ACKNOWLEDGMENTS

This work was only possible with the co-operation of many individuals and institutions. I
wish to record my sincere thanks to Prof Titus Msagati and Prof Bhekie Mamba for their
supervision and significant academic support throughout my studies. My special
appreciation goes to the University of Johannesburg and the Department of Science
and Technology/Mintek’s Nanotechnology Innovation Centre for funding this project. I
greatly acknowledge Prof Omotayo Arotiba, Prof Sabelo Mhlanga and Dr Edward
Nxumalo for their valuable inputs, seminars and professional expertise. I extend my
gratitude to Ms Nomsa Baloyi of Extraction Metallurgy for SEM/EDS and X-ray
diffraction analysis, Mr Siyasanga Mpelane of Mintek for HRTEM analysis and Dr Petrus
Venter, the DWAF: WRM Quality Manager of the Hartbeespoort Dam Integrated
Biological Remediation Programme, for willingly helping with sampling and technical
aspects of the Hartbeespoort Dam. I also would like to acknowledge my fellow

colleagues from the Department of Applied Chemistry: Dr Thabo Nkambule, for helping
me with special constructions of the exposure tanks and laboratory staff for creating a
warm atmosphere, facilitating interesting discussions and social activities. Mr
Njongenhle Nyoni, thank you for endless hours of reading and criticising my thesis - I
appreciate your straightforward editing. To my wife Nonhlanhla, how could I ever
complete a day’s work without you picking up the slack and organising my schedule?
Thank you. I am ever mindful of the unparalleled love, support and patience of my
family. Finally, above all things, I would like to acknowledge the only wise God, who has
constantly amazed me with His wisdom and divine enablement throughout this work.

v
PRESENTATIONS AND PUBLICATIONS

Conference presentation

1. H. Nyoni, T.A.M. Msagati, B. Mamba. Calibration of a passive, in situ, integrative
sampler for monitoring of biotoxins in aquatic environments. 14th
WaterNet/WARFSA/GWP-SA Symposium 2013, 30th October -1st November, Dar
es salaam, Tanzania, Oral presentation.

Publications

1. H. Nyoni, T.A.M. Msagati, B. Mamba. (2014), Calibration of a Passive, in situ,
Integrative Sampler for Monitoring of Biotoxins in Aquatic Environments, Water
Science & Technology; Water Supply, doi: 10.2166/ws.2015.080
2. Nyoni H, Mamba BB, Msagati TAM (2015) In situ measurement of the time-
weighted average concentrations of cylindrospermopsin and microcystin LR-YR-

RR in natural waters using silicone-membrane/γ-Fe O -nanoparticle-sorbent
2 3
passive sampling device, J Environ Anal Toxicol, 5: 270. doi: 10.4172/2161-
0525.1000270
3. H. Nyoni, T.A.M. Msagati, B. Mamba. Environmental monitoring of
cylindrospermopsin and microcystin LR-YR-RR in the Hartbeespoort dam using a
newly developed silicone-membrane/γ-Fe O -nanoparticle-sorbent based
2 3
passive sampler alongside CHEMCATCHER (polar version), POCIS
pharmaceutical configuration and SPE technique (grab sampling), (Submitted to
Science of the total Environment , February 2015)

vi
TABLE OF CONTENTS

AFFIDAVIT ................................................................................................................................... i
ABSTRACT ................................................................................................................................. ii
DEDICATION ............................................................................................................................. iv
ACKNOWLEDGEMENTS............................................................................................................ v
PRESENTATIONS AND PUBLICATIONS .................................................................................. vi
Conference presentation ......................................................................................................... vi
Publications ............................................................................................................................ vi
LIST OF FIGURES AND SCHEMES ............................................................................................. xii
LIST OF TABLES .................................................................................................................... xviii
LIST OF ABBREVIATIONS ........................................................................................................... xix
CHAPTER 1 - INTRODUCTION ..................................................................................................1
1.1 Background ...................................................................................................................1
1.2 Problem statement ........................................................................................................... 3
1.3 Justification of study ......................................................................................................4
1.4 Objectives of the study ..................................................................................................6

1.5 Outline of the thesis ......................................................................................................7

1.6 References ...................................................................................................................8
CHAPTER 2 - LITERATURE REVIEW ......................................................................................... 11
2.1 Environmental concerns of microcystins and cylindrospermopsin ................................ 11
2.2 Instrumental analysis of microcystins and cylindrospermopsin ..................................... 18
2.2.1 High performance liquid chromatography (HPLC) ...................................................... 18
2.2.2 HPLC detectors ......................................................................................................... 20
2.2.3 Gas chromatography (GC) ........................................................................................... 27
2.2.4 Capillary electrophoresis (CE) ................................................................................... 28
2.2.5 Thin layer chromatography (TLC) .............................................................................. 29
2.2.6 Enzyme-Linked Immunosorbent Assay (ELISA)......................................................... 29
2.3 Overview of passive sampling ..................................................................................... 30
2.4 Theory of analyte exchange between passive samplers and water .............................. 39

vii
TABLE OF CONTENTS
2.4.1 Equilibrium passive samplers .................................................................................... 42
2.4.2 Kinetic passive samplers ........................................................................................... 42
2.4.3 Environmental factors affecting passive sampler performance ................................... 43
2.4.4 Use of performance reference compounds ................................................................ 45
2.4.5 The use of passive samplers with bioassays ............................................................. 46
2.5 Novelty and theory of the developed passive sampler ................................................. 47
2.6 Alternative techniques to passive samplers ................................................................. 49
2.6.1 Active sampling ......................................................................................................... 49
2.6.2 Bio monitoring organisms .......................................................................................... 50
2.7 Quality Control ............................................................................................................ 51
2.8 References ................................................................................................................. 52
CHAPTER 3 - RESEARCH METHODOLOGY........................................................................... 76
3.1 Materials and methods ................................................................................................ 76
3.1.1 Chemicals and materials ........................................................................................... 76
3.1.2 Microcystin and cylindrospermopsin mixture .............................................................. 77
3.2 Synthesis of iron oxide (maghemite) nanoparticles ...................................................... 77
3.3 Experimental design: flow through exposure system ................................................... 79

3.4 Solid phase extraction technique ................................................................................. 81

3.5 Fabrication of different samplers ................................................................................. 84
3.5.1 Silicone-membrane/γ-Fe O -nanoparticle-sorbent based passive sampler ................. 84
2 3
3.5.2 Polar organic chemical integrative sampler (POCIS) .................................................. 85
3.5.3 Chemcatcher passive sampler ................................................................................... 86
3.6 Chromatographic separation of microcystins ............................................................... 88
3.6.1 High performance liquid chromatography (HPLC) ...................................................... 88
3.6.2 Gas Chromatography – mass spectrometer (GC x GC ToFMS) ................................ 88
3.7 Field evaluation of the passive sampling devices......................................................... 89
3.8 References ................................................................................................................. 91
CHAPTER 4 - CALIBRATION OF A PASSIVE, IN SITU, INTEGRATIVE SAMPLER FOR
MONITORING OF BIOTOXINS IN AQUATIC ENVIRONMENTS ................................................ 93
4.1 Introduction ................................................................................................................. 93

viii