Assessment of a portable UV–Vis spectrophotometer's performance for stream water DOC and Fe content monitoring in remote areas

Quantification of dissolved organic carbon (DOC) and iron (Fe) in surface waters is critical for understanding the water quality dynamics, brownification balance northern hemisphere. Especially remote areas, sampling laboratory analysis DOC Fe content at a sufficient temporal frequency difficult. Ultraviolet–visible (UV–Vis) spectrophotometry promising tool monitoring to increase applications regions. The aim this study was (1) investigate performance an in-situ UV–Vis spectrophotometer detecting spectral absorbances comparison with benchtop instrument; (2) analyse stability estimates from spectrophotometers among different rivers using multivariate methods; (3) compare site-specific calibration models pooled extrapolation predictions one catchment another. This indicates that were measured by sensor explained 96% absorbance data instrument. Among three tested methods, multiple stepwise regression (MSR) best model both predictions. Accurate unbiased watersheds built successfully, these could be extrapolated watershed another even without DOC. However, combination datasets not possible.