ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments
Biogenic silica is the major component of the external skeleton of marine micro-organisms, such as diatoms, which, after the organisms death, settle down onto the seabed. These micro-organisms are involved in the CO<sub>2</sub> cycle because they remove it from the atmosphere through pho...
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MDPI AG
2019-10-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/24/21/3927 |
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| author | Dora Melucci Alessandro Zappi Francesca Poggioli Pietro Morozzi Federico Giglio Laura Tositti |
| author_facet | Dora Melucci Alessandro Zappi Francesca Poggioli Pietro Morozzi Federico Giglio Laura Tositti |
| author_sort | Dora Melucci |
| collection | DOAJ |
| description | Biogenic silica is the major component of the external skeleton of marine micro-organisms, such as diatoms, which, after the organisms death, settle down onto the seabed. These micro-organisms are involved in the CO<sub>2</sub> cycle because they remove it from the atmosphere through photosynthesis. The biogenic silica content in marine sediments, therefore, is an indicator of primary productivity in present and past epochs, which is useful to study the CO<sub>2</sub> trends. Quantification of biosilica in sediments is traditionally carried out by wet chemistry followed by spectrophotometry, a time-consuming analytical method that, besides being destructive, is affected by a strong risk of analytical biases owing to the dissolution of other silicatic components in the mineral matrix. In the present work, the biosilica content was directly evaluated in sediment samples, without chemically altering them, by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Quantification was performed by combining the multivariate standard addition method (MSAM) with the net analyte signal (NAS) procedure to solve the strong matrix effect of sediment samples. Twenty-one sediment samples from a sediment core and one reference standard sample were analyzed, and the results (extrapolated concentrations) were found to be comparable to those obtained by the traditional wet method, thus demonstrating the feasibility of the ATR-FTIR-MSAM-NAS approach as an alternative method for the quantification of biosilica. Future developments will cover in depth investigation on biosilica from other biogenic sources, the extension of the method to sediments of other provenance, and the use higher resolution IR spectrometers. |
| first_indexed | 2024-12-16T10:01:00Z |
| format | Article |
| id | doaj.art-7fb9e86e3afa42a5b3fc6e86b4539124 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-16T10:01:00Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-7fb9e86e3afa42a5b3fc6e86b45391242022-12-21T22:35:47ZengMDPI AGMolecules1420-30492019-10-012421392710.3390/molecules24213927molecules24213927ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine SedimentsDora Melucci0Alessandro Zappi1Francesca Poggioli2Pietro Morozzi3Federico Giglio4Laura Tositti5Department of Chemistry “G. Ciamician”, University of Bologna, 40126 Bologna, ItalyDepartment of Chemistry “G. Ciamician”, University of Bologna, 40126 Bologna, ItalyDepartment of Chemistry “G. Ciamician”, University of Bologna, 40126 Bologna, ItalyDepartment of Chemistry “G. Ciamician”, University of Bologna, 40126 Bologna, ItalyPolar Science Institute-National Research Council ISP-CNR, Via P. Gobetti 101, 40129 Bologna, ItalyDepartment of Chemistry “G. Ciamician”, University of Bologna, 40126 Bologna, ItalyBiogenic silica is the major component of the external skeleton of marine micro-organisms, such as diatoms, which, after the organisms death, settle down onto the seabed. These micro-organisms are involved in the CO<sub>2</sub> cycle because they remove it from the atmosphere through photosynthesis. The biogenic silica content in marine sediments, therefore, is an indicator of primary productivity in present and past epochs, which is useful to study the CO<sub>2</sub> trends. Quantification of biosilica in sediments is traditionally carried out by wet chemistry followed by spectrophotometry, a time-consuming analytical method that, besides being destructive, is affected by a strong risk of analytical biases owing to the dissolution of other silicatic components in the mineral matrix. In the present work, the biosilica content was directly evaluated in sediment samples, without chemically altering them, by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Quantification was performed by combining the multivariate standard addition method (MSAM) with the net analyte signal (NAS) procedure to solve the strong matrix effect of sediment samples. Twenty-one sediment samples from a sediment core and one reference standard sample were analyzed, and the results (extrapolated concentrations) were found to be comparable to those obtained by the traditional wet method, thus demonstrating the feasibility of the ATR-FTIR-MSAM-NAS approach as an alternative method for the quantification of biosilica. Future developments will cover in depth investigation on biosilica from other biogenic sources, the extension of the method to sediments of other provenance, and the use higher resolution IR spectrometers.https://www.mdpi.com/1420-3049/24/21/3927diatomsbiogenic silicaatr-ftirchemometricsnas |
| spellingShingle | Dora Melucci Alessandro Zappi Francesca Poggioli Pietro Morozzi Federico Giglio Laura Tositti ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments Molecules diatoms biogenic silica atr-ftir chemometrics nas |
| title | ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments |
| title_full | ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments |
| title_fullStr | ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments |
| title_full_unstemmed | ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments |
| title_short | ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments |
| title_sort | atr ftir spectroscopy a new non destructive approach for the quantitative determination of biogenic silica in marine sediments |
| topic | diatoms biogenic silica atr-ftir chemometrics nas |
| url | https://www.mdpi.com/1420-3049/24/21/3927 |
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