Addressing the measurement of particulate organic and inorganic phosphorus in estuarine and coastal waters

Abstract

a b s t r a c tThe speciation of particulate phosphorus (TPP) into inorganic (PIP) and organic phosphorus (POP), has been scarcely investigated in suspended particulate matter (SPM), contrary to numerous sediment studies. This work evaluates the actual capacity of methods for TPP, POP and PIP determination in SPM to measure efficiently and specifically each pool. Methods were tested on a range of plankton-associated organic and inorganic P compounds, on microalgal cultures and estuarine samples. Then results are specifically discussed reviewing P speciation in phytoplankton. For TPP analysis, the method of Solórzano and Sharp (1980) is recommended compared with that of Aspila et al. (1976), originally dedicated to sediment, as there is one step less, the protocol is more explicit (use of MgSO 4 ) and it provides the best results. The application of the original protocol of the Aspila method for TPP (no MgSO 4 ) results in underestimated and highly variable values. For POP, the CWO (Chemical Wet Oxidation) method tested here succeeds in providing sufficient oxidation of organic P, but, inorganic polyphosphate is yet too significantly hydrolysed, and intracellular phosphate, an underestimated PIP fraction, contributes to the POP pool with this method. Finally the Aspila method for PIP is the best compromise in estimating the contribution of PIP to TPP and POP by difference. Even if particulate polyphosphate is only partially hydrolysed (41-49%), intracellular phosphate is included and only a very low percentage of organic P, essentially nucleotidic P, is attacked. In any case, our findings show clear evidence of the necessity to fully describe the procedure when P speciation methods are used.

High alkaline phosphatase activity in phosphate replete waters: The case of two macrotidal estuaries

“…TPP was determined as precisely described in Labry et al (), the original method being that of Solórzano and Sharp (). Filters placed in a borosilicate vial were dried with 2 mL of 0.017 mol L −1 MgSO 4 in a 95°C oven for 3 h, then ashed at 480°C for 2 h. After cooling, they were acid‐hydrolyzed in 5 mL of 0.2 mol L −1 HCl in an 80°C oven for 30 min.…”

Phytoplankton Blooms at Increasing Levels of Atmospheric Carbon Dioxide: Experimental Evidence for Negative Effects on Prymnesiophytes and Positive on Small Picoeukaryotes

“…POP, DOP and BSi were measured following Hansen and Koroleff (1999) on a Hitachi U2000 spectrophotometer, Chla and other phytoplankton pigments on a WATERS high performance liquid chromatograph (HPLC) equipped with a Varian Microsorb-MV 100-3 C8 column according to Barlow et al (1997), and DOC and DON as detailed in Engel et al (2014) and described by Qian and Mopper (1996) and Cauwet (1999) on a Shimadzu TOC-VCH. Further details on actual analytical procedures can be found in and it is noted that the here reported POP might comprise an inorganic phase (Labry et al, 2012).…”

The Relationship among Dissolved Inorganic Phosphate, Particulate Inorganic Phosphate, and Chlorophyll-a in Different Seasons in the Coastal Seas of Semarang and Jepara

“…The form of P particulates (PIP) was determined by extracting with 1 M HCl (Aspila et al 1976), filtering and supernatant were analyzed using the Molybdenum blue method (Labry et al 2013). The absorbance value was measured using a Shimadzu UV-VIS Optima spectrophotometer SP 3000, with 1 cm wide cuvet.…”

“…The data were analyzed with the SPSS statistical software v. 16 and Microsoft Office Excel 2007. The normality tests were performed on all data, before further analysis of the regression model.…”