PhD BSc(Hons) (Otago)
Tel: 03 479 7913
Location: Science II 3n12
Email: rfrew@chemistry.otago.ac.nz
Main research interests
- Trace metals in natural waters
- Stable isotope geochemistry
- Paleo-chemistry
- Geochemical provenancing
Current research projects
Determining the geographical origin of food and other commodities of interest:
The geochemical composition of a natural product provides a inherent signature that can be related to its point of origin. We are currently working on developing robust tools encompassing analyses (light isotopes, trace metals and heavy isotopes), databasing and statistical interpretation. Projects on whole foods (e.g. honey, coffee, edible oils) are on-going and attention is now on deciphering the signal within complex mixtures.
Nitrogen in the oceans, fate and fluxes:
Nitrogen compounds i the ocean play an important role in sustaining primary productivity and some are implicated as potential climate modifiers. However the the controls of the rates and pathways of the cycling of nitrogen from the relatively inert N2(g) through the essential nutrients NO3 and NH4, amino acids and various gaseous oxides is not well understood. The potential of climate change underlines the importance of understanding the marine biogeochemistry of nitrogen. For example, the regions of nitrogen fixation will increase with global warming thereby enhancing the marine fixed nitrogen pool. On the other hand nitrous oxide is a significant greenhouse gas with a global warming potential 300 times that of CO2 on a molecular basis. This project applies isotopic tools to unravel the complexities of the marine nitrogen systematics.
Publications
Wakefield, J., McComb, K., Ehtesham, E., Van Hale, R., Barr, D., Hoogewerff, J., & Frew, R. (2019). Chemical profiling of saffron for authentication of origin. Food Control, 106, 106699. doi: 10.1016/j.foodcont.2019.06.025
Sabadel, A. J. M., Van Oostende, N., Ward, B. B., Woodward, E. M. S., Van Hale, R., & Frew, R. D. (2019). Characterization of particulate organic matter cycling during a summer North Atlantic phytoplankton bloom using amino acid C and N stable isotopes. Marine Chemistry. Advance online publication. doi: 10.1016/j.marchem.2019.103670
Holder, P. W., Van Hale, R. J., Frew, R., George, S., & Armstrong, K. F. (2019). Natal origin of the invasive biosecurity pest, brown marmorated stink bug (Halyomorpha halys: Penatomidae), determined by dual-element stable isotope-ratio mass spectrometry. Pest Management Science. Advance online publication. doi: 10.1002/ps.5659
Zhu, D., Hayman, A., Kebede, B., Stewart, I., Chen, G., & Frew, R. (2019). 31P NMR-based phospholipid fingerprinting of powdered infant formula. Journal of Agricultural & Food Chemistry, 67(36), 10265-10272. doi: 10.1021/acs.jafc.9b03902
Udy, J., Wing, S., O'Connell-Milne, S., Kolodzey, S., McMullin, R., Durante, L., & Frew, R. (2019). Organic matter derived from kelp supports a large proportion of biomass in temperate rocky reef fish communities: Implications for ecosystem-based management. Aquatic Conservation. Advance online publication. doi: 10.1002/aqc.3101
Chapter in Book - Research
McComb, K., & Frew, R. (2013). Using new analytical approaches to verify the origin of honey. In P. Brereton (Ed.), New analytical approaches for verifying the origin of food. (pp. 216-242). Cambridge, UK: Woodhead. doi: 10.1533/9780857097590.3.216
Sander, S. G., Hunter, K., & Frew, R. (2009). Sampling and measurements of trace metals in seawater. In O. Wurl (Ed.), Practical guidelines for the analysis of seawater. (pp. 305-327). Boca Raton, FL: CRC Press.
North, J. C., & Frew, R. D. (2007). Isotopic characterisation of leachate from seven New Zealand landfills. In E. C. Lehmann (Ed.), Landfill research focus. (pp. 199-261). New York: Nova Science.
Heywood, K. J., Locarnini, R. A., Frew, R. D., King, B. A., & Dennis, P. (1998). Transport and water masses of the Antarctic slope front system in the eastern Weddell sea. In S. Jacobs & R. Weiss (Eds.), Ocean, Ice and Atmosphere: Interactions at the Antartic Continential Margin. (pp. 203-214). AGU Antarctic Research Series.
Dennis, P. J., Heywood, K. J., & Frew, R. D. (1997). Oxygen Isotope Studies. In R. T. Pollard & D. Smythe-Wright (Eds.), Understanding Ocean Circulation. (pp. 31-32). UK: WOCE.
Journal - Research Article
Wakefield, J., McComb, K., Ehtesham, E., Van Hale, R., Barr, D., Hoogewerff, J., & Frew, R. (2019). Chemical profiling of saffron for authentication of origin. Food Control, 106, 106699. doi: 10.1016/j.foodcont.2019.06.025
Udy, J., Wing, S., O'Connell-Milne, S., Kolodzey, S., McMullin, R., Durante, L., & Frew, R. (2019). Organic matter derived from kelp supports a large proportion of biomass in temperate rocky reef fish communities: Implications for ecosystem-based management. Aquatic Conservation. Advance online publication. doi: 10.1002/aqc.3101
Zhu, D., Hayman, A., Kebede, B., Stewart, I., Chen, G., & Frew, R. (2019). 31P NMR-based phospholipid fingerprinting of powdered infant formula. Journal of Agricultural & Food Chemistry, 67(36), 10265-10272. doi: 10.1021/acs.jafc.9b03902
Holder, P. W., Van Hale, R. J., Frew, R., George, S., & Armstrong, K. F. (2019). Natal origin of the invasive biosecurity pest, brown marmorated stink bug (Halyomorpha halys: Penatomidae), determined by dual-element stable isotope-ratio mass spectrometry. Pest Management Science. Advance online publication. doi: 10.1002/ps.5659
Sabadel, A. J. M., Van Oostende, N., Ward, B. B., Woodward, E. M. S., Van Hale, R., & Frew, R. D. (2019). Characterization of particulate organic matter cycling during a summer North Atlantic phytoplankton bloom using amino acid C and N stable isotopes. Marine Chemistry. Advance online publication. doi: 10.1016/j.marchem.2019.103670
Udy, J. A., Wing, S. R., O'Connell-Milne, S. A., Durante, L. M., McMullin, R. M., Kolodzey, S., & Frew, R. D. (2019). Regional differences in supply of organic matter from kelp forests drive trophodynamics of temperate reef fish. Marine Ecology Progress Series, 621, 19-32. doi: 10.3354/meps12974
Van Hale, R., Schofield, M., Connor, M., Barker, R., & Frew, R. (2019). Stable isotope measurements to differentiate sources of monofluoroacetate in a blackmail case. Rapid Communications in Mass Spectrometry. Advance online publication. doi: 10.1002/rcm.8416
Gorman, A. R., Vennell, R., Holbrook, W. S., & Frew, R. (2018). Seismic characterization of oceanic water masses, water mass boundaries and mesoscale eddies SE of New Zealand. Journal of Geophysical Research: Oceans, 123(2), 1519-1532. doi: 10.1002/2017JC013459
Babaranti, O., Horn, S., Jowett, T., & Frew, R. (2018). Isotopic signatures in Mytilus galloprovincialis and Ulva latuca as bioindicators for assessing discharged sewage effluent in coastal waters along Otago Peninsula, New Zealand. Geology, Ecology, & Landscapes. Advance online publication. doi: 10.1080/24749508.2018.1485079
Rajapaksha, D., Waduge, V., Padilla‐Alvarez, R., Kalpage, M., Rathnayake, R. M. N. P., Migliori, A., Frew, R., … Amarakoon, T. (2017). XRF to support food traceability studies: Classification of Sri Lankan tea based on their region of origin. X-Ray Spectrometry, 46(4), 220-224. doi: 10.1002/xrs.2748
Wing, S. R., Gault-Ringold, M., Stirling, C. H., Wing, L. C., Shatova, O. A., & Frew, R. D. (2017). δ56Fe in seabird guano reveals extensive recycling of iron in the Southern Ocean ecosystem. Limnology & Oceanography, 62(4), 1671-1681. doi: 10.1002/lno.10524
Sabadel, A. J. M., Browning, T. J., Kruimer, D., Airs, R. L., Woodward, E. M. S., Van Hale, R., & Frew, R. D. (2017). Determination of picomolar dissolved free amino acids along a South Atlantic transect using reversed-phase high-performance liquid chromatography. Marine Chemistry, 196, 173-180. doi: 10.1016/j.marchem.2017.09.008
Li, Q., Zhao, Y., Zhu, D., Pang, X., Liu, Y., Frew, R., & Chen, G. (2017). Lipidomics profiling of goat milk, soymilk and bovine milk by UPLC-Q-Exactive Orbitrap Mass Spectrometry. Food Chemistry, 224, 302-309. doi: 10.1016/j.foodchem.2016.12.083
Li, Q., Yu, Z., Zhu, D., Meng, X., Pang, X., Liu, Y., Frew, R., … Chen, G. (2017). The application of NMR-based milk metabolite analysis in milk authenticity identification. Journal of the Science of Food & Agriculture, 97(9), 2875-2882. doi: 10.1002/jsfa.8118
Li, Q., Meng, X., Zhu, D., Pang, X., Wang, K., Frew, R., & Chen, G. (2016). Determination of nonprotein nitrogen components of milk by nuclear magnetic resonance. Analytical Letters, 49(18), 2953-2963. doi: 10.1080/00032719.2016.1164180
Sabadel, A. J. M., Woodward, E. M. S., Van Hale, R., & Frew, R. D. (2016). Compound-specific isotope analysis of amino-acids: A tool to unravel complex symbiotic trophic relationships. Food Webs, 6, 9-18. doi: 10.1016/j.fooweb.2015.12.003
Nielsen, J. A., Frew, R. D., Whigham, P. A., Callaway, R. M., & Dickinson, K. J. M. (2016). Thyme travels: 15N isoscapes of Thymus vulgaris L. invasion in lightly grazed pastoral communities. Austral Ecology, 41(1), 28-39. doi: 10.1111/aec.12284
Holder, P. W., Frew, R., & Van Hale, R. (2015). The geographic origin of an intercepted biosecurity pest beetle assigned using hydrogen stable isotopes. Journal of Economic Entomology, 108(2), 834-837. doi: 10.1093/jee/tou097
Nielsen, J. A., Whigham, P. A., Frew, R. D., Callaway, R. M., & Dickinson, K. J. M. (2015). Thyme and space invasion: Thymus vulgaris decreases exotic plant species diversity in Central Otago, New Zealand. Biological Invasions, 17(8), 2261-2274. doi: 10.1007/s10530-015-0872-9
Muhammad, S. A., Frew, R. D., & Hayman, A. R. (2015). Compound-specific isotope analysis of diesel fuels in a forensic investigation. Frontiers in Chemistry, 3, 12. doi: 10.3389/fchem.2015.00012
Muhammad, S. A., Hayman, A. R., Van Hale, R., & Frew, R. D. (2015). Assessing carbon and hydrogen isotopic fractionation of diesel fuel n-alkanes during progressive evaporation. Journal of Forensic Sciences, 60(S1), S56-S65. doi: 10.1111/1556-4029.12551
Nielsen, J. A., Frew, R. D., Whigham, P. A., Callaway, R. M., & Dickinson, K. J. M. (2015). Germination and growth responses of co-occurring grass species to soil from under invasive Thymus vulgaris. Allelopathy, 35(1), 139-152.
Jandrić, Z., Haughey, S. A., Frew, R. D., McComb, K., Galvin-King, P., Elliott, C. T., & Cannavan, A. (2015). Discrimination of honey of different floral origins by a combination of various chemical parameters. Food Chemistry, 189, 52-59. doi: 10.1016/j.foodchem.2014.11.165
Parr, E. B., Cotter, J. D., Frew, R. D., & Rehrer, N. J. (2015). Muscle glycogen dominates females fuel usage in moderately intensive endurance exercise even in the cold. Annals of Sports Medicine & Research, 2(3), 1021.
Sander, S. G., Tian, F., Ibisanmi, E. B., Currie, K. I., Hunter, K. A., & Frew, R. D. (2015). Spatial and seasonal variation of the iron speciation in surface waters of the Subantarctic front and the Otago Continental Shelf. Marine Chemistry, 173, 114-124. doi: 10.1016/j.marchem.2014.09.001
Ehtesham, E., Hayman, A., Van Hale, R., & Frew, R. (2015). Influence of feed and water on the stable isotopic composition of dairy milk. International Dairy Journal, 47, 37-45. doi: 10.1016/j.idairyj.2015.02.008
Wing, S. R., Jack, L., Shatova, O., Leichter, J. J., Barr, D., Frew, R. D., & Gault-Ringold, M. (2014). Seabirds and marine mammals redistribute bioavailable iron in the Southern Ocean. Marine Ecology Progress Series, 510, 1-13. doi: 10.3354/meps10923
Nielsen, J. A., Frew, R. D., Whigham, P. A., Callaway, R. M., & Dickinson, K. J. M. (2014). Thyme invasion and soil properties in the Central Otago region of New Zealand. Geoderma Regional, 1, 48-58. doi: 10.1016/j.geodrs.2014.08.002
Nielsen, J. A., Whigham, P. A., Frew, R. D., Callaway, R. M., & Dickinson, K. J. M. (2014). Invasion essentials: Does secondary chemistry plasticity contribute to the invasiveness of Thymus vulgaris L.? Chemoecology, 24(1), 15-27. doi: 10.1007/s00049-013-0142-1
Holder, P. W., Armstrong, K., Van Hale, R., Millet, M.-A., Frew, R., Clough, T. J., & Baker, J. A. (2014). Isotopes and trace elements as natal origin markers of Helicoverpa armigera: An experimental model for biosecurity pests. PLoS ONE, 9(3), e92384. doi: 10.1371/journal.pone.0092384
Benbow, T. J., Hayman, A. R., Van Hale, R., & Frew, R. (2013). Preparation of aqueous fatty acids for hydrogen and carbon stable isotope analysis by solid phase extraction. Marine & Freshwater Research, 64(4), 294-302. doi: 10.1071/MF12192
Ehtesham, E., Hayman, A. R., McComb, K. A., Van Hale, R., & Frew, R. D. (2013). Correlation of geographical location with the stable isotope values of hydrogen and carbon of fatty acids from New Zealand milk and bulk milk powder. Journal of Agricultural & Food Chemistry, 61(37), 8914-8923. doi: 10.1021/jf4024883
Frew, R., McComb, K., Croudis, L., Clark, D., & Van Hale, R. (2013). Modified sugar adulteration test applied to New Zealand honey. Food Chemistry, 141(4), 4127-4131. doi: 10.1016/j.foodchem.2013.06.124
McLeod, R. J., Garland, M., Van Hale, R., Steiman, S., & Frew, R. D. (2013). Determining the most effective combination of chemical parameters for differentiating the geographic origin of food products: An example using coffee beans. Journal of Food Chemistry & Nutrition, 1(2), 49-61.
Muhammad, S. A., Frew, R. D., & Hayman, A. R. (2013). Forensic differentiation of diesel fuels using hydrocarbon isotope fingerprints. Central European Geology, 56(1), 19-37. doi: 10.1556/CEuGeol.56.2013.1.3
Ehtesham, E., Baisden, W. T., Keller, E. D., Hayman, A. R., Van Hale, R., & Frew, R. D. (2013). Correlation between precipitation and geographical location of the δ2H values of the fatty acids in milk and bulk milk powder. Geochimica et Cosmochimica Acta, 111, 105-116. doi: 10.1016/j.gca.2012.10.026
McLeod, R. J., Hyndes, G. A., Hurd, C. L., & Frew, R. D. (2013). Unexpected shifts in fatty acid composition in response to diet in a common littoral amphipod. Marine Ecology Progress Series, 479, 1-12. doi: 10.3354/meps10327
Hepburn, C. D., Frew, R. D., & Hurd, C. L. (2012). Uptake and transport of nitrogen derived from sessile epifauna in the giant kelp Macrocystis pyrifera. Aquatic Biology, 14(2), 121-128. doi: 10.3354/ab00382
Wing, S. R., McLeod, R. J., Leichter, J. J., Frew, R. D., & Lamare, M. D. (2012). Sea ice microbial production supports Ross Sea benthic communities: Influence of a small but stable subsidy. Ecology, 93(2), 314-323. doi: 10.1890/11-0996.1
Strzepek, R. F., Hunter, K. A., Frew, R. D., Harrison, P. J., & Boyd, P. W. (2012). Iron-light interactions differ in Southern Ocean phytoplankton. Limnology & Oceanography, 57(4), 1182-1200. doi: 10.4319/lo.2012.57.4.1182
Fitzsimons, S., Mager, S., Frew, R., Clifford, A., & Wilson, G. (2012). Formation of ice-shelf moraines by accretion of sea water and marine sediment at the southern margin of the McMurdo Ice Shelf, Antarctica. Annals of Glaciology, 53(60), 211-220. doi: 10.3189/2012AoG60A155
Gault-Ringold, M., Adu, T., Stirling, C. H., Frew, R. D., & Hunter, K. A. (2012). Anomalous biogeochemical behavior of cadmium in subantarctic surface waters: Mechanistic constraints from cadmium isotopes. Earth & Planetary Science Letters, 341–344, 94-103. doi: 10.1016/j.epsl.2012.06.005
Fukuda, K., Thomas, D. B., Frew, R. D., & Fordyce, R. E. (2012). Antarctic glaciation recorded in Early Miocene New Zealand foraminifera. Marine Micropaleontology, 92–93, 52-60. doi: 10.1016/j.marmicro.2012.05.002
Smith, I. J., Langhorne, P. J., Frew, R. D., Vennell, R., & Haskell, T. G. (2012). Sea ice growth rates near ice shelves. Cold Regions Science & Technology, 83-84, 57-70. doi: 10.1016/j.coldregions.2012.06.005
Stokes, M. D., Leichter, J. J., Wing, S., & Frew, R. (2011). Temperature variability and algal isotopic heterogeneity on a Floridian coral reef. Marine Ecology, 32(3), 364-379. doi: 10.1111/j.1439-0485.2011.00469.x
