title: High-resolution, two-dimensional measurement of dissolved reactive phosphorus in sediments using the diffusive gradients in thin films technique in combination with a routine procedure.
abstract: Dissolved reactive phosphorus (DRP) is the most available P form in sediments and often directly controls phytoplankton blooms in aquatic systems. In this study, a novel procedure was developed for two-dimensional (2D) measurement of DRP in sediments at a spatial resolution of 0.45 mm using the diffusive gradients in thin films (DGT) technique with a revised high-capacity binding phase (Zr oxide gel). This procedure involves DGT uptake of P in sediments, 2D slicing of the binding gel on a 0.45 × 0.45-mm grid system, elution of P from each gel square with 1 M NaOH, and microcolorimetric determination of DRP in each eluted solution using 384-microwell plates. Measurements of DRP via this procedure were tested in homogeneous solutions and sediments and produced an acceptable error (<20% relative standard deviation) for the analysis once the accumulated mass of P in each gel square reached 1.2 μg cm(-2). This method was successfully applied to produce 2D images of the DRP distribution in sediments with and without the influence of tubificid worm bioturbation, revealing a much more pronounced and localized impact from tubificid worms than that found using a one-dimensional measurement of pore water DRP concentrations at 1-cm resolution.
authors: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. smding@niglas.ac.cn
authors: Shiming
authors: S
authors: Ding
authors: Fei
authors: F
authors: Jia
authors: Di
authors: D
authors: Xu
authors: Qin
authors: Q
authors: Sun
authors: Lei
authors: L
authors: Zhang
authors: Chengxin
authors: C
authors: Fan
authors: Chaosheng
authors: C
authors: Zhang
mesh_terms: D004058:Diffusion; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005782:Gels / Q000737:chemistry; D019015:Geologic Sediments / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015040:Zirconium / Q000737:chemistry
chemical_list: D005782:Gels; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D015040:Zirconium; C028541:zirconium oxide