Determination of low phosphate concentrations in seawater by an isobutyl acetate extraction procedure

Cescon, Bruno; Scarazzato, Paolo

doi:10.4319/lo.1973.18.3.0499

Cited by 10 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After the algal culturing period, dissolved phosphate was measured by isobutyl acetate extraction (34) trations were <0.1 pM dissolved phosphate in both samples, suggesting an efficient depletion of P during the algal culturing period. This result and the direct dependence of S on PTo support the hypothesis of yield limitation by P in S-3.…”

Section: Resultsmentioning

confidence: 93%

Phosphorus-zinc interactive effects on growth by Selenastrum capricornutum (Chlorophyta)

Kuwabara¹

1985

Environ. Sci. Technol.

View full text Add to dashboard Cite

rn Culturing experiments in chemically defined growth media were conducted to observe possible Zn and P interactions on Selenastrum capricornutum Printz growth indexes. Elevated Zn concentrations (7.5 X and 1.5 X lo-' M [Zn2+]) were highly detrimental to algal growth, affecting lag, exponential, and stationary growth phases. P behaved as a yield-limiting nutrient with maximum cell densities increasing linearly with total P. This yield limitation was intensified at elevated Zn concentrations. Although calculated cellular phosphorus concentrations increased markedly with Zn ion activity, elevated Zn concentrations had no apparent effect on rates of phosphorus uptake estimated for Selenastrum during exponential growth. Results indicated that P-Zn interactions were significant in describing Selenastwm cell yield results and are consistent with previous Zn studies on chlorophytes. These P-Zn interactions and the observed inhibitory growth effects of submicromolar Zn concentrations suggest that in nature an apparent P yield-limiting condition may result from elevated Zn concentrations.Not subject to US.

show abstract

Section: Resultsmentioning

confidence: 93%

Phosphorus-zinc interactive effects on growth by Selenastrum capricornutum (Chlorophyta)

Kuwabara¹

1985

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Phosphorus, on the other hand, may be less subject to such analytical problems because of its availability in carrier-free radioisotopic form and because techniques for measuring extremely low concentrations have been developed (e. g. Strickland and Parson, 1972;Cescon and Scarazzato, 1973). Furthermore, because of the apparent close interrelationship between nitrogen and phosphorus in the biological production cycle (e. g. Redfield et al, 1963) and particularly in oceanic waters (Perry and Eppley, 1981), studies of the dynamics of phosphorus cycling are clearly relevant to the more general question of how nutrient regeneration processes regulate primary production rate.…”

Section: Introductionmentioning

confidence: 99%

Uptake and Recycling of Soluble Reactive Phosphorus by Marine Microplankton

Harrison¹

1983

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Simultaneous measurements of soluble reactive phosphorus (SRP) uptake and regeneration (using isotope-dilution methodology) by natural marine microplankton populations are described for coastal and oceanic waters. Seasonal fluctuations in SRP fluxes in Bedford Basin (Canada) were characterized by high uptake and low regeneration rates during spring and fall bloom periods and higher relative (compared with uptake) and absolute regeneration rates during summer. On an annual basis, SRP regeneration by microplankton could meet ca. 50 % of the phosphorus requirements for planktonic production. In oceanic waters microplankton were also important in recycling SRP, providing > 60 % of the P-requirements for growth in the Peruvian upwelling region and in the Eastern Tropical Pacific Ocean. At times, > 100 % of uptake requirements may be supplied by microplankton in Arctic waters. Size-fractionation studies showed that SRP uptake and regeneration were generally partitioned by particle size with relatively greater regeneration rates associated wlth organisms larger than l pm in size.

show abstract

“…SRP (soluble reactive phosphorus) was measured (in /jg P 1-1) after extraction of the molybdate complex with 10 ml isobutyle acetate from 200 ml filtered sample (Golterman, 1969;Cescon & Scarazzato 1973). SRSi (soluble reactive silicate) and NO 3 + NO 2 were also measured colourimetrically (Golterman, 1969).…”

Section: Methodsmentioning

confidence: 99%

Biotests with phytoplankton assemblages. Growth limitation along temporal and spatial gradients

Løvstad

1986

Hydrobiologia

View full text Add to dashboard Cite

The development of eight different species (populations) along temporal and vertical gradients in several lakes was studied. Many populations had an exponential growth phase and a decline phase. The growth rate was often high during the exponential phase. Some species, e.g. Oscillatoria spp. and Synedra cf. acus, often also had a long stationary phase. The growth rate and the sinking rate of these populations were often very low.Laboratory batch experiments with dilute phytoplankton populations were carried out to estimate the degree of growth limitation (L) for different populations sample from different lakes during the three growth phases. L was always low and often zero for populations initially in the exponential phase and always high for populations initially in the decline phase. The biotests also gave results that can help to explain the vertical distribution of Oscillatoria or Asterionella in three lakes investigated.The results indicate that the growth rates and the development of the populations were dependent on the external chemical and physical conditions. The transition between the different growth phases seemed often to be dependent on the external nutrient conditions. P, N, Si and Fe were probably the most growth-limiting nutrients. The growth rate of some diatoms was probably limited directly or indirectly at high pH.Laboratory biotests with natural populations may give valuable information on the growth-properties of different populations in the lakes. The biotests should, however, be carried out in combination with chemical and physical measurements and quantitative determinations of population densities.

show abstract

Determination of low phosphate concentrations in seawater by an isobutyl acetate extraction procedure

Abstract: Isobutyl acetate is proposed as an extracting reagent for the determination of low phosphate concentrations in seawater. Since this ester is immiscible with water, its use improves both the accuracy and the ease of the method.

Cited by 10 publications

References 0 publications

Phosphorus-zinc interactive effects on growth by Selenastrum capricornutum (Chlorophyta)

Phosphorus-zinc interactive effects on growth by Selenastrum capricornutum (Chlorophyta)

Uptake and Recycling of Soluble Reactive Phosphorus by Marine Microplankton

Biotests with phytoplankton assemblages. Growth limitation along temporal and spatial gradients

Contact Info

Product

Resources

About