Patent Description:
The present relates to a method of analyzing potassium content in soil, the method comprising: a) obtaining a soil sample; b) adding a liquid to the soil sample to form a soil slurry; c) flowing the soil slurry through a filter to form a filtrate; d) blending a reagent composition with the filtrate to form a soil mixture; and e) flowing the soil mixture through an analysis tool along a flow direction whereby a potassium absorbance of the soil mixture is measured; and wherein the flow direction is oriented such that the soil mixture flows orthogonal to the direction of gravity.

In other embodiments, the present disclosure includes a method of analyzing potassium content in soil, the method comprising: a) obtaining a soil sample; b) adding a liquid to the soil sample to form a soil slurry; c) flowing the soil slurry through a filter to form a filtrate; d) blending a reagent composition with the filtrate to form a soil mixture; and e) flowing the soil mixture through an analysis tool along a flow direction whereby a potassium absorbance of the soil mixture is measured; and wherein the soil mixture comprises a surfactant and the flow direction is substantially horizontal and orthogonal to the direction of gravity.

Moreover, the features and benefits of the disclosure are illustrated by reference to the exemplified embodiments. The present invention is defined by the claims appended hereto.

According to an embodiment of the present disclosure, potassium may be tested according to the following methodologies. A soil sample may be obtained and blended with liquid to create the soil slurry. The soil slurry may then flow through the filter element to create a filtrate, whereby one or more reagent may be added to the filtrate to create a mixture.

The soil mixture may then be analyzed for potassium content by absorbance that may be read via a spectrophotometer at a wave length ranging from <NUM> to <NUM> - preferably <NUM> to about <NUM> - including all wavelengths and sub-ranges there-between.

In alternative embodiments, the potassium content analysis may occur inside of the analysis tool <NUM> and as the soil mixture flows along the horizontal FD, whereby the horizontal FD is substantially orthogonal to the gravitational direction GD and the soil slurry flows horizontally through the analysis tool <NUM>.

According to embodiments of the potassium content analysis using the horizontal FD, a surfactant may be added to the soil slurry. It has been surprisingly discovered that the addition of an anionic surfactant provides an unexpected improvement in optical clarity that enhances the spectrophotometer potassium content analysis while other non-anionic surfactants fail to provide such improved optical properties. Non-limiting examples of anionic surfactant include sodium laurate phosphate, sodium laurate sulfate, and sodium dodecyl sulfate. The surfactant of this embodiment may be substantially free of non-ionic compounds. The surfactant of this embodiment may be substantially free of cationic compounds.

According to the embodiments directed to the potassium analysis, non-limiting examples of reagents include lithium hydroxide, sodium hydroxide, tetraphenylborate in sodium hydroxide, and sodium tetraborate decahydate in glycerol.

The reagents may comprise a first reagent that includes lithium hydroxide is present in a concentration of about <NUM> to about <NUM> - including all concentrations and sub-ranges there-between. The reagents may comprise a second reagent that includes tetraphenylborate in a concentration of <NUM> % to <NUM> % - including all concentrations and sub-ranges there-between - and NaOH in a concentration of about <NUM> to about <NUM> - including all concentrations and sub-ranges there-between. The reagents may comprise a third reagent that includes sodium tetraborate decahydrate in a concentration ranging from about <NUM> to about <NUM> - including all concentrations and sub-ranges there-between - in about <NUM> % to about <NUM> % aqueous glyercol - including all concentrations and sub-ranges there-between.

An extractant may be blended with the soil slurry. Non-limiting examples of extractant include nitric acid. The extractant may comprise nitric acid in a concentration ranging from about <NUM> to about <NUM> - including all concentrations and sub-ranges there-between.

According to this embodiment, the soil sample may be prepared by mixing the filtrate with the first reagent, subsequently mixing with the second reagent, subsequently mixing <NUM> of the third reagent, and subsequently performing the absorbance reading.

According to this embodiment, the soil slurry and soil mixture may not be subjected to a centrifuge force before performing the potassium absorbance reading.

A first experiment was performed to test the impact of horizontal FD and vertical FD as it relates to surfactant for a potassium soil analysis.

The samples of Examples <NUM>-<NUM> were prepared by blending soil and water together at a <NUM>:<NUM> ratio to create a slurry, whereby the slurry is pulled into the extraction portion of the system and potassium is extracted in a <NUM>:<NUM> ratio of slurry to extractant with <NUM> nitric acid. After extraction, the extracted samples were filtered and the filtrate was subsequently blended with reagent to create a soil mixture, the reagent including lithium hydroxide solution and then subsequently mixed with tetraphenylborate in NaOH, and subsequently, each sample is mixed with sodium tetraborate decahydrate in glycerol and sodium dodecyl sulfate (SDS) in an aqueous solution. Each soil mixture of Examples <NUM>-<NUM> were then flowed along the horizontal FD through the analysis tool.

The sample of Example <NUM> included a non-ionic surfactant. The sample of Example <NUM> included an anionic surfactant. The sample of Example <NUM> included a cationic surfactant. The sample of Example <NUM> was free of surfactant.

The samples of Examples <NUM>-<NUM> were prepared by blending soil and water together at a <NUM>:<NUM> ratio to create a slurry, whereby the slurry is pulled into the extraction portion of the system and potassium is extracted in a <NUM>:<NUM> ratio of slurry to extractant with <NUM> nitric acid. After extraction, the extracted samples were filtered and the filtrate was subsequently blended with reagent to create a soil mixture, the reagent including lithium hydroxide solution and then subsequently mixed with tetraphenylborate in NaOH, and subsequently, each sample is mixed with sodium tetraborate decahydrate in glycerol and sodium dodecyl sulfate (SDS) in an aqueous solution. Each soil mixture of Examples <NUM>-<NUM> were then flowed along the vertical FD through the analysis tool.

Each sample of Examples <NUM>-<NUM> were analyzed by the analysis tool at a wavelength between <NUM> - <NUM> to determine the potassium concentration in the sample. After mixing, each sample produces turbidity and the ability to read through each sample was recorded as either a pass or fail value - whereby the pass value equates to an optical property sufficiently clear to allow for the reading of the potassium concentration at a wavelength between <NUM> - <NUM> and the fail value equates to an optical property insufficiently clear to not allow for reading of the potassium concentration at a wavelength between <NUM> - <NUM>. The results are set forth below in Table <NUM>.

Claim 1:
A method of analyzing potassium content in soil, the method comprising:
a) obtaining a soil sample;
b) adding a liquid comprising a surfactant to the soil sample to form a soil slurry;
c) flowing the soil slurry through a filter to form a filtrate;
d) blending a reagent composition with the filtrate to form a soil mixture; and
e) flowing the soil mixture through an analysis tool along a flow direction and performing chemical analysis on the soil mixture flowing through the analysis tool, whereby a potassium absorbance of the soil mixture is measured; and
wherein the flow direction is substantially orthogonal to the direction of gravity.