|
|||||
|
|
Independent measurement of biogenic silica in sediments by FTIR spectroscopy and PLS regression |
|
| Authors: | Carsten Meyer-Jacob Hendrik Vogel Florian Boxberg Peter Rosén Michael E Weber Richard Bindler |
| Institution: | 1. Department of Ecology and Environmental Science, Ume? University, 901 87, Ume?, Sweden 2. Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Baltzerstrasse 1+3, 3012, Bern, Switzerland 3. Institute of Geology and Mineralogy, University of Cologne, Zuelpicher Str. 49a, 50674, Cologne, Germany 5. MARUM – Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, 28359, Bremen, Germany |
| Abstract: | We present an independent calibration model for the determination of biogenic silica (BSi) in sediments, developed from analysis of synthetic sediment mixtures and application of Fourier transform infrared spectroscopy (FTIRS) and partial least squares regression (PLSR) modeling. In contrast to current FTIRS applications for quantifying BSi, this new calibration is independent from conventional wet-chemical techniques and their associated measurement uncertainties. This approach also removes the need for developing internal calibrations between the two methods for individual sediments records. For the independent calibration, we produced six series of different synthetic sediment mixtures using two purified diatom extracts, with one extract mixed with quartz sand, calcite, 60/40 quartz/calcite and two different natural sediments, and a second extract mixed with one of the natural sediments. A total of 306 samples—51 samples per series—yielded BSi contents ranging from 0 to 100 %. The resulting PLSR calibration model between the FTIR spectral information and the defined BSi concentration of the synthetic sediment mixtures exhibits a strong cross-validated correlation ( \( {\text{R}}^{ 2}_{\text{cv}} \) = 0.97) and a low root-mean square error of cross-validation (RMSECV = 4.7 %). Application of the independent calibration to natural lacustrine and marine sediments yields robust BSi reconstructions. At present, the synthetic mixtures do not include the variation in organic matter that occurs in natural samples, which may explain the somewhat lower prediction accuracy of the calibration model for organic-rich samples. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |