Quantifying tropical peatland dissolved organic carbon (DOC) using UV-visible spectroscopy

• Published in: Water research (Oxford) Vol. 115; pp. 229 - 235
• Main Authors: Cook, Sarah, Peacock, Mike, Evans, Chris D., Page, Susan E., Whelan, Mick J., Gauci, Vincent, Kho, Lip Khoon
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.05.2017
• Subjects: Carbon; DOC; Fresh Water - chemistry; Sarawak; Spectrophotometry; Spectrophotometry, Ultraviolet; Tropical peat; Water; Water samples; DOC; Sarawak; Spectrophotometry; Tropical peat; Water samples
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2017.02.059

UV–visible spectroscopy has been shown to be a useful technique for determining dissolved organic carbon (DOC) concentrations. However, at present we are unaware of any studies in the literature that have investigated the suitability of this approach for tropical DOC water samples from any tropical peatlands, although some work has been performed in other tropical environments. We used water samples from two oil palm estates in Sarawak, Malaysia to: i) investigate the suitability of both single and two-wavelength proxies for tropical DOC determination; ii) develop a calibration dataset and set of parameters to calculate DOC concentrations indirectly; iii) provide tropical researchers with guidance on the best spectrophotometric approaches to use in future analyses of DOC. Both single and two-wavelength model approaches performed well with no one model significantly outperforming the other. The predictive ability of the models suggests that UV–visible spectroscopy is both a viable and low cost method for rapidly analyzing DOC in water samples immediately post-collection, which can be important when working at remote field sites with access to only basic laboratory facilities. [Display omitted] •Tropical dissolved organic carbon can be determined using UV–visible spectroscopy.•Both single and two-wavelength model approaches perform well.•There is a threshold concentration (60 mg L−1) at which DOC cannot be determined.•Provides a viable/low cost method offering rapid sample analysis post-collection.