Total soluble phosphorus

Total Soluble Phosphorus. Total soluble phosphorus includes soluble orthophosphate (soluble condensed phosphate if present) and soluble organic phosphorus. A membrane-filtered sample is treated to release phosphorus as orthophosphate from combination with organic matter and condensed phosphates by some form of oxidation (and hydrolysis). 

Information concerning the metabolic function of unusual naturally occurring plant constituents might be used to develop new growth regulators. An example of a development that arose in this way began with the observation by Tolbert (143) that as much as 30% of the total soluble phosphorus in plant roots, and sometimes in the leaves,... 

The first hurdle encountered during the development of alfalfa as a recombinant protein production system was the relative inefficiency of the available expression cassettes. A study in which a tomato proteinase inhibitor I transgene was expressed in tobacco and alfalfa under the control of the cauliflower mosaic virus (CaMV) 35S promoter showed that 3-4 times more protein accumulated in tobacco leaves compared to alfalfa leaves [5]. Despite the low efficiency of the CaMV 35S promoter in alfalfa, bio-pharmaceutical production using this system has been reported in the scientific literature. Such reports include expression of the foot and mouth disease virus antigen [6], an enzyme to improve phosphorus utilization [7] and the anti-human IgG C5-1 [8]. In this last work, the C5-1 antibody accumulated to 1% total soluble protein [8]. 

Figure 4. Summer averages and winter maxima of phosphorus species soluble reactive P (SRP) (a) and total P (TP) (b). Bars are summer averages shaded, treatment and unshaded, reference. Squares are winter maxima black, treatment and white, reference.

For these reasons, numerous attempts have been made to identify and characterize DOP, but with little success because it is usually present in very low concentrations. Typical values in lake waters range from 5 to 100 xg of P/L in oligotrophic to eutrophic systems. Colorimetric methods have been used extensively to detect and differentiate between soluble reactive phosphorus (SRP) and soluble unreactive phosphorus (SUP) at concentrations as low as 10 xg of P/L (I). SRP is generally considered to consist of only orthophosphate compounds, whereas SUP is composed of all other phosphorus species, primarily organic phosphorus compounds. The sum of SRP and SUP is equal to the total soluble phosphorus (TSP). These methods were used to study the dynamics of bulk phosphorus fractionation between the sediments, suspended particulate matter, the biota, and the dissolved fraction (2). Despite these studies, very little is known regarding the identity and characteristics of the DOP in the hydrosphere. 

Lake-Water Samples. Ten lake-water samples were collected from September 1990 to May 1991. The total soluble phosphorus concentration for the concentrated samples ranged from 23.8 to 60.8 mg of P/L, and the soluble reactive phosphorus concentrations ranged from 1.0 to 18.1 mg of P/L (Table I). Dissolved organic carbon concentration values for the concentrated samples ranged from 5000 to 20,000 mg of C/L. The signal-to-noise ratios from 12-14-h runs achieved for the NMR spectra range from 3.0 to 7.0. The pH of the concentrated samples after the addition of FeEDTA fell between the values of 7.00 and 8.00. Addition of the FeEDTA increased the pH by only a few tenths of a pH unit. 

Figure 12. 31P FT-NMR spectrum of Crystal Lake sample G, 1000-dalton membrane retentate fraction, before and after alkaline bromination. The total soluble phosphorus concentration was 50 mg of P/L.

The nutritional composition of ripe edible aril indicates that mangosteen contains a high percentage of carbohydrates, mostly in sugar form. It is relatively low in minerals and vitamins. The calcium and phosphorus content is high. The percentage of total soluble solids ranges from 13 to 15.2% in immature and 18.3 to 19% in mature fruits (Table 19.2). 

Digestion by boiling in the presence pf 30% hydrogen peroxide (Jackson (8)) yielded incomplete recoveries of total soluble phosphorus from all the estuarine water samples tested and from organic media such as Difco tryptone and peptone. Moreover, the method failed to yield quantitative recovery of an orthophosphate standard carried through the test procedure. 

Table VI. Comparison of Several Techniques for the Analysis of Total Soluble Phosphorus (Based on Recovery)...

The precision of the persulfate digestion technique for the determination of total soluble phosphorus was tested on estuarine water samples of widely differing salinity at total soluble phosphorus concentrations varying between 60-100 /xg. P/liter. The maximum coeflBcient of variation of the technique was 1.2% (Table V). 

Chemical analyses can measure the total quantities of N, P and K in FYM but not their availability to the crop. At most, all of the N in FYM is combined with organic substances and is released only when they decay in practice about a third of the nitrogen is released quite quickly, but much is very resistant and persists in the soil. Much of the phosphorus is also combined with the organic matter but approximately half is quickly available. Most of the potassium is soluble in water and is quickly available to the crop. 

Total phosphorus includes colloidal inorganic phosphate, casein (organic) phosphate, soluble inorganic phosphate, ester phosphate and phospholipids. 

A number of instrumental analytical techniques can be used to measure the total phosphorus content of organophosphorus compounds, regardless of the chemical bonding of phosphorus within the molecules, as opposed to the determination of phosphate in mineralized samples. If the substances are soluble, there is no need for their destruction and for the conversion of phosphorus into phosphate, a considerable advantage over chemical procedures. The most important methods are flame photometry and inductively coupled plasma atomic emission spectrometry the previously described atomic absorption spectrometry is sometimes useful. 

Schwer and Clausen (1989) reported that a fescue/ryegrass/bluegrass filter strip retained 89% of the phosphorus from dairy milk-house wastewater. Vought et al. (1994), summarizing his own research on phosphorus removal from surface runoff, noted exponential removal with 66% and 95% of soluble phosphorus retained in the first 8 and 16m of buffer strip, respectively. Daniels and Gilliam (1996) determined that fescue and riparian filter strips reduced total phosphorus load by 50%, but that 80% of the soluble phosphorus frequently moved through the strips. 

Under no-flow conditions where sufficient time had passed to establish chemical equilibrium, the right-hand side of Eqs. (9.5)-(9.8) would equal zero and could be solved simultaneously to provide a relationship between the total sorbed quantity q of phosphorus and the concentration A of water-soluble phosphorus. For the linear case where the order of the reaction n = 1, the relationship is... 

P has a 14.3-day half-life and emits an energetic f particle, making 21P useful for nutritional studies in plants and animals. A 0.01 - xCi sample of 32P in the form of a soluble phosphate was added to a hydroponic bath containing a young tomato plant. Exactly three weeks later, the entire plant was rinsed, dried, and liquefied in a blender. A portion of the preparation was placed in a total activity counter. In a 1.00-min period an average of 625 counts was recorded. How efficient was the tomato plant in utilizing the phosphorus ... 

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