Comparison of two methods for the isolation of phytolith occluded carbon from plant material
- 798 Downloads
Background and aims
Phytolith occluded carbon (PhytOC) is of interest for isotope studies, dating of sediments and the capture and storage of carbon. Many methodologies have been used for the isolation of phytoliths from plant material; however, there are wide disparities in the PhytOC contents when determined by different methodologies. In this study we examine the utility of the two main methods used for quantifying PhytOC.
These methods are: (1) a microwave digestion followed by a Walkley-Black digestion, and (2) H2SO4/H2O2.
Method (1) produced PhytOC values over 50 times higher than those acquired by method (2). SEM examination indicated that the differences were likely due to shattering of the phytoliths by method (2) allowing consumption by the acid and peroxide of PhytOC .
These results indicate that for the samples analysed here: 1] the modified microwave method allowed the total PhytOC to be measured, 2] the H2SO4/H2O2 method allowed the PhytOC within the tightly packed silica matrix to be measured, and 3] the PhytOC retained within the phytolith cavities could possibly be calculated by subtracting 2] from 1]. For the samples analysed here most of the PhytOC resided in the phytolith cavities.
KeywordsPhytolith occluded carbon PhytOC Phytolith Plantstone Plant silica
This research was funded by an Australian Research Council (ARC), Discovery Grant (DP0773868), the Australian Institute for Nuclear Science and Engineering, and Southern Cross GeoScience at Southern Cross University. The authors also wish to thank reviewer Martin Hodson for constructive comments and Yash Dang, Bede O’Mara and Dale Kirby of the Department of Primary Industries and Fisheries Queensland and Mr Robert Quirk canefarmer NSW for their assistance in plant collecting and access to field trials they were conducting.
- Bertoldi de Pomar H (1971) Ameghiniana 8:317–328, English summaryGoogle Scholar
- Bowdery D (1989) Phytolith analysis: introduction and applications. In: Beck WI, Clarke A, Head L (eds) Plants in Australian archaeology, archaeology and material culture studies in anthropology, tempus vol 1. Watson Ferguson & Company, Brisbane, pp 161–86Google Scholar
- Clifford HT, Watson L (1977) Identifying grasses: Data, methods and illustrations. University of Queensland Press, BrisbaneGoogle Scholar
- Deines P, (1980) The isotopic composition of reduced organic carbon. In: Fritz P, Fontes JC (eds), Handbook of Environmental Isotope Geochemistry. Elsevier, New York, pp 329–406Google Scholar
- Elbaum R, Weiner S, Albert RM, Elbaum M (2003) Detection of burning of plant materials in the archaeological record by changes in the refractive indices of siliceous phytoliths. J Archaeol Sci 30(217–226)Google Scholar
- Geiss JW (1978) Biogenic silica in three species of Gramineae. Ann Bot 42:1119–1129Google Scholar
- Hart DM (1998) Sample preparation techniques,. In: D. Hart, G.S. Humphreys and R.J. Field (Editors), Australasian Phytolith Workshop,. Geoecology Group, School of Earth Sciences, Macquarie University, Macquarie University, Sydney, pp. 9–16Google Scholar
- Lanning FC, Hopkins TL, Loera JC (1980) Silica and ash content and depositional patterns in tissues of mature Zea mays L. plants. Ann Bot 45:549–554Google Scholar
- Mulholland SC, Prior CA (1993) AMS radiocabon dating of phytoliths. In: Pearsall DM, Piperno DR (eds) MASCA research papers in science and archaeology. University of Pennsylvania, Philadelphia, pp 21–23Google Scholar
- Murphy DB (2002) Fundamentals of Light Microscopy and Electronic Imaging. A John Wiley & Sons, Inc., 121 ppGoogle Scholar
- Parr JF, Farrugia K (2003) Waste reduction and value adding during fossil phytolith extraction and palaeo-environmental analysis of volcanic sediments and tephra using Microwave Digestion and ICPMS. In: L. Wallace and D. Hart (Editors), Conference; The state of the art in phytolith and starch research, in the Australian-Pacific-Asian regions. Pandanus Press, terra australis, 15:19–30, Canberra, pp. 19–30Google Scholar
- Pearsall DM (1989) Paleoethnobotany: a handbook of procedures. Academic Press, Inc., LondonGoogle Scholar
- Piperno DR (1988) Phytolith analysis: an archaeological and geological perspective. Academic, LondonGoogle Scholar
- Reichert ET (1913) The Differentiation and Specificity of Starches in Relation to Genera, Species, Etc. Volumes I and II., Volumes I and II. Chapman, LondonGoogle Scholar
- Rovner I (1983) Plant opal phytolith analysis: major advances in archaeobotanical research. In: Schiffer MBE (ed) Advances in archaeological method and theory, vol 6. Academic Press, London pp 225–66Google Scholar
- Runge F (1998) The effect of dry oxidation temperatures (500–800°C) and of natural corrosion on opal phytoliths. In: Meunier JD, Faure-Denard L (eds) Second international meeting on phytolith research. Aix-en-Provence, Cerage, p 73Google Scholar
- Sakai WS, Thom M (1979) Localization of silicon in specific cell wall layers of the stomatal apparatus of sugarcane by use of energy dispersive X-ray analysis. Ann Bot 44:245–248Google Scholar
- Sangster AG, Williams SE, Hodson MJ (1997) Silica deposition in the needles of the gymnosperms. II. Scanning electron microscopy and x-ray microanalysis. In: Pinilla, A., Juan-Tresserras, J., & Machado, M.J., (Editors), The State-of-the-art of Phytoliths in Soils and Plants. Monografia 4 del Centro de Ciencias Medioambientales, CISC. Madrid. 135–146Google Scholar
- Santos GM et al (2010) The phytolith 14c puzzle: a tale of background determinations and accuracy tests. Radiocarbon 52:113–128Google Scholar
- Santos GM et al (2012) Possible source of ancient carbon in phytolith concentrates from harvested grasses. Biogeosciences 9:329–356Google Scholar
- Smith FA, Anderson KB (2001) Characterization of organic compounds in phytoliths: improving the resolving power of phytolith d13C as a tool for paleoecological reconstruction of C3 and C4 grasses. In: Meunier JD, Colin F (eds) Phytoliths: applications in earth science and human history. A.A. Balkema Publishers, Rotterdam pp 317–327Google Scholar
- Stewart WD, Arthur JM (1935) An improved standardized method for ashing of plant material. Am J Bot 22:905Google Scholar
- Taffs KH, Parr JF, Bolton KGE (2006) Using palaeobotany to resolve ecological disasters in East Australian peatlands. Ecol Manag Restor 7(2):132–135Google Scholar
- WHO (1998) Quality control methods for medicinal plant materials. Office of Publications. World Health Organisation, Geneva, 16 ppGoogle Scholar